diff --git a/src/core/task/Task.ts b/src/core/task/Task.ts index 4de2b84590..b6b6b18ded 100644 --- a/src/core/task/Task.ts +++ b/src/core/task/Task.ts @@ -111,6 +111,7 @@ import { buildNativeToolsArrayWithRestrictions } from "./build-tools" import { ToolRepetitionDetector } from "../tools/ToolRepetitionDetector" import { restoreTodoListForTask } from "../tools/UpdateTodoListTool" import { FileContextTracker } from "../context-tracking/FileContextTracker" +import { ObservationRegistry } from "./observationRegistry" import { RooIgnoreController } from "../ignore/RooIgnoreController" import { RooProtectedController } from "../protect/RooProtectedController" import { type AssistantMessageContent, presentAssistantMessage } from "../assistant-message" @@ -286,6 +287,10 @@ export class Task extends EventEmitter implements TaskLike { readonly instanceId: string readonly metadata: TaskMetadata + // The observed on-disk version of each file this task has read. Declared here so the + // read tools can record it; a write guard later compares a token against this registry. + readonly observationRegistry = new ObservationRegistry() + todoList?: TodoItem[] readonly rootTask: Task | undefined = undefined @@ -383,6 +388,12 @@ export class Task extends EventEmitter implements TaskLike { providerRef: WeakRef private readonly globalStoragePath: string abort: boolean = false + // Monotonic cancellation counter. `abort` is a mutable flag that resumeAfterDelegation + // resets to false, so a write still waiting on a path chain cannot tell from `abort` + // alone that the task was cancelled while it waited - the flag may be back to false by + // the time its turn comes. Every cancellation bumps this counter, and the guarded-write + // path compares the value it captured when the write was queued. + cancellationGeneration: number = 0 currentRequestAbortController?: AbortController /** * Controller for the waiter on an in-flight `ensureModelFetched()` call (see @@ -3259,6 +3270,7 @@ export class Task extends EventEmitter implements TaskLike { } this.abort = true + this.cancellationGeneration++ this.cancelAssistantMessagePersistence() this.abortPromise ??= this.abortTaskOnce() return this.abortPromise @@ -3344,6 +3356,7 @@ export class Task extends EventEmitter implements TaskLike { // signals below are cancelled and a request already past those checks // could still build tools and call `createMessage()`. this.abort = true + this.cancellationGeneration++ // Cancel any in-progress HTTP request try { diff --git a/src/core/task/__tests__/Task.spec.ts b/src/core/task/__tests__/Task.spec.ts index 06f07d2e02..86c732b4cc 100644 --- a/src/core/task/__tests__/Task.spec.ts +++ b/src/core/task/__tests__/Task.spec.ts @@ -3208,6 +3208,54 @@ describe("Cline", () => { ).toHaveLength(1) }) + it("advances the cancellation generation on each cancellation and keeps it advanced across a resume", async () => { + // The S4a write guard compares the cancellation generation a queued write + // captured against the generation at publish time. The abort FLAG cannot do that + // on its own: resumeAfterDelegation() clears it, and a write that belongs to the + // cancelled run would then publish as if nothing had been cancelled. Only the + // generation keeps the two runs apart, so it must never go backwards. + const task = new Task({ + provider: mockProvider, + apiConfiguration: mockApiConfig, + task: "test task", + startTask: false, + }) + vi.spyOn(task, "dispose").mockResolvedValue(undefined) + + expect(task.cancellationGeneration).toBe(0) + + await task.abortTask() + expect(task.abort).toBe(true) + expect(task.cancellationGeneration).toBe(1) + + await task.resumeAfterDelegation() + expect(task.abort).toBe(false) + expect(task.cancellationGeneration).toBe(1) + + await task.abortTask() + expect(task.abort).toBe(true) + expect(task.cancellationGeneration).toBe(2) + }) + + it("advances the cancellation generation on disposal, without any explicit cancel", async () => { + // A task torn down by the host never sees abortTask(). Disposal has to raise the + // same generation, or a write still parked on its path chain publishes after the + // task is gone. + const task = new Task({ + provider: mockProvider, + apiConfiguration: mockApiConfig, + task: "test task", + startTask: false, + }) + + expect(task.cancellationGeneration).toBe(0) + + await task.dispose() + + expect(task.abort).toBe(true) + expect(task.cancellationGeneration).toBe(1) + }) + it("flushes pending state before TaskAborted and disposal while queue state is intact", async () => { const task = new Task({ provider: mockProvider, diff --git a/src/core/task/__tests__/observationRegistry.spec.ts b/src/core/task/__tests__/observationRegistry.spec.ts new file mode 100644 index 0000000000..a3c55ebc6d --- /dev/null +++ b/src/core/task/__tests__/observationRegistry.spec.ts @@ -0,0 +1,108 @@ +import { describe, it, expect, vi } from "vitest" + +import { ObservationRegistry } from "../observationRegistry" + +describe("ObservationRegistry", () => { + it("observe → get returns the recorded version and observedAt", () => { + const reg = new ObservationRegistry() + reg.observe("/a/b/c.ts", "1:2:300:4000000000:5000000000") + + const obs = reg.get("/a/b/c.ts") + expect(obs).toBeDefined() + expect(obs!.version).toBe("1:2:300:4000000000:5000000000") + expect(typeof obs!.observedAt).toBe("number") + }) + + it("re-observe replaces the entry with a fresh observedAt", () => { + vi.useFakeTimers() + const reg = new ObservationRegistry() + reg.observe("/a/b/c.ts", "v1") + const first = reg.get("/a/b/c.ts")! + expect(first.version).toBe("v1") + + vi.advanceTimersByTime(50) + reg.observe("/a/b/c.ts", "v2") + const second = reg.get("/a/b/c.ts")! + expect(second.version).toBe("v2") + expect(second.observedAt).toBeGreaterThan(first.observedAt) + + vi.useRealTimers() + }) + + it("has returns true for observed paths, false otherwise", () => { + const reg = new ObservationRegistry() + reg.observe("/x.ts", "t1") + expect(reg.has("/x.ts")).toBe(true) + expect(reg.has("/y.ts")).toBe(false) + }) + + it("size reflects the number of observed entries", () => { + const reg = new ObservationRegistry() + expect(reg.size).toBe(0) + reg.observe("/a.ts", "t1") + reg.observe("/b.ts", "t2") + expect(reg.size).toBe(2) + }) + + it("clear removes all entries and resets size to 0", () => { + const reg = new ObservationRegistry() + reg.observe("/a.ts", "t1") + reg.observe("/b.ts", "t2") + reg.clear() + expect(reg.size).toBe(0) + expect(reg.get("/a.ts")).toBeUndefined() + expect(reg.has("/b.ts")).toBe(false) + }) + + it("get on empty registry returns undefined", () => { + const reg = new ObservationRegistry() + expect(reg.get("/any.ts")).toBeUndefined() + }) + + it("separate instances are independent — observing in one does not appear in the other", () => { + const regA = new ObservationRegistry() + const regB = new ObservationRegistry() + regA.observe("/shared.ts", "v1") + expect(regA.get("/shared.ts")).toBeDefined() + expect(regB.get("/shared.ts")).toBeUndefined() + regB.observe("/shared.ts", "v2") + expect(regA.get("/shared.ts")!.version).toBe("v1") + expect(regB.get("/shared.ts")!.version).toBe("v2") + }) + + describe("completeness scope (S4b follow-up #46)", () => { + it("defaults to a complete observation when the read scope is not given", () => { + const reg = new ObservationRegistry() + reg.observe("/a/b/c.ts", "v1") + + expect(reg.get("/a/b/c.ts")!.complete).toBe(true) + }) + + it("records a partial observation when the read only returned a view of the file", () => { + const reg = new ObservationRegistry() + reg.observe("/a/b/c.ts", "v1", false) + + expect(reg.get("/a/b/c.ts")!.complete).toBe(false) + }) + + it("re-observing replaces the entry's completeness with the new read's scope", () => { + const reg = new ObservationRegistry() + reg.observe("/a/b/c.ts", "v1", false) + reg.observe("/a/b/c.ts", "v2") + + const obs = reg.get("/a/b/c.ts")! + expect(obs.version).toBe("v2") + expect(obs.complete).toBe(true) + }) + + it("re-observing with a partial scope downgrades a previously complete entry", () => { + const reg = new ObservationRegistry() + reg.observe("/a/b/c.ts", "v1") + reg.observe("/a/b/c.ts", "v2", false) + + const obs = reg.get("/a/b/c.ts")! + expect(obs.version).toBe("v2") + expect(obs.complete).toBe(false) + }) + }) +}) diff --git a/src/core/task/observationRegistry.ts b/src/core/task/observationRegistry.ts new file mode 100644 index 0000000000..0ef9115f21 --- /dev/null +++ b/src/core/task/observationRegistry.ts @@ -0,0 +1,59 @@ +/** + * Per-task file observation registry (upstream epic #1375, phase A2). + * + * Each Task owns its own instance so parent and subtask observations are + * independent. The S4 guarded-write will compare these versions against the + * token recomputed pre-write to detect stale reads or file replacement. + * + * Pure in-memory — zero I/O, no dependencies. The S4 guarded-write consults + * these observations for the version check and for the completeness check that + * gates a full-file replacement. + */ + +export interface FileObservation { + /** Version token derived from on-disk fs.stat (bigint mode). */ + version: string + /** Millisecond timestamp when the observation was recorded. */ + observedAt: number + /** + * Whether the read that produced this observation returned the complete + * file. A slice, line-range, truncated, or indentation-block read returns + * only a view of the file; such an observation authorizes targeted edits + * on the view the model saw, but never a full-file replacement. + */ + complete: boolean +} + +export class ObservationRegistry { + private readonly entries = new Map() + + /** + * Record an observation for a file at its absolute path. + * + * Re-observing replaces the entry with a fresh observedAt timestamp, the + * new version token, and the read's completeness. `complete` defaults to + * true for callers that read the whole file themselves (spec doubles, + * WriteToFileTool). A caller whose read is internal to a targeted edit must + * carry the model's prior completeness instead, so the tool's own read cannot + * upgrade a partial read into authority for a full-file replacement. + */ + observe(absolutePath: string, version: string, complete: boolean = true): void { + this.entries.set(absolutePath, { version, observedAt: Date.now(), complete }) + } + + get(absolutePath: string): FileObservation | undefined { + return this.entries.get(absolutePath) + } + + has(absolutePath: string): boolean { + return this.entries.has(absolutePath) + } + + clear(): void { + this.entries.clear() + } + + get size(): number { + return this.entries.size + } +} diff --git a/src/core/tools/ReadFileTool.ts b/src/core/tools/ReadFileTool.ts index 2107cfe21b..e61c9cc808 100644 --- a/src/core/tools/ReadFileTool.ts +++ b/src/core/tools/ReadFileTool.ts @@ -16,13 +16,14 @@ import type { ReadFileParams, ReadFileMode, ReadFileToolParams, FileEntry, LineR import { isLegacyReadFileParams, type ClineSayTool } from "@roo-code/types" import { Task } from "../task/Task" +import { versionTokenOfStat } from "../../utils/versionToken" import { formatResponse } from "../prompts/responses" import { RecordSource } from "../context-tracking/FileContextTrackerTypes" import { isPathOutsideWorkspace } from "../../utils/pathUtils" import { getReadablePath } from "../../utils/path" import { extractTextFromFile, addLineNumbers, getSupportedBinaryFormats } from "../../integrations/misc/extract-text" import { readWithIndentation, readWithSlice } from "../../integrations/misc/indentation-reader" -import { DEFAULT_LINE_LIMIT } from "../prompts/tools/native-tools/read_file" +import { DEFAULT_LINE_LIMIT, MAX_LINE_LENGTH } from "../prompts/tools/native-tools/read_file" import type { ToolUse, PushToolResult } from "../../shared/tools" import { @@ -214,14 +215,36 @@ export class ReadFileTool extends BaseTool<"read_file"> { // Read text file content with lossy UTF-8 conversion // Reading as Buffer first allows graceful handling of non-UTF8 bytes // (they become U+FFFD replacement characters instead of throwing) + // A2 (epic #1375): capture the on-disk token before the read so a mutation + // landing mid-read is detected by the post-read stat below. + const preReadStats = await fs.stat(fullPath, { bigint: true }).catch(() => undefined) const buffer = await fs.readFile(fullPath) const fileContent = buffer.toString("utf-8") - const result = this.processTextFile(fileContent, entry) + // A lossy decode is not the whole file: the model never saw those bytes. + const lossyDecode = !Buffer.from(fileContent).equals(buffer) + // S4b follow-up (#46 / epic #1375): processTextFile reports whether the + // returned content is the whole file; the observation below records that + // scope so the write guard can deny full-file updates built on a partial view. + const processed = this.processTextFile(fileContent, entry) await task.fileContextTracker.trackFileContext(relPath, "read_tool" as RecordSource) + // A2 (plan #33 / epic #1375): record the observed on-disk version for the future write guard. + // The token is captured before AND after the read; the target is observed only + // when both match — a mutation between the two stats means the content the model + // received is not the on-disk state, and observing it would let a later write + // match a token the model never saw. A stat failure leaves the target + // unobserved and never fails the read. + const postReadStats = await fs.stat(fullPath, { bigint: true }).catch(() => undefined) + if (preReadStats && postReadStats) { + const preReadToken = versionTokenOfStat(preReadStats) + if (preReadToken === versionTokenOfStat(postReadStats)) { + task.observationRegistry.observe(fullPath, preReadToken, processed.complete && !lossyDecode) + } + } + updateFileResult(relPath, { - nativeContent: `File: ${relPath}\n${result}`, + nativeContent: `File: ${relPath}\n${processed.content}`, }) } catch (error) { const errorMsg = error instanceof Error ? error.message : String(error) @@ -265,8 +288,14 @@ export class ReadFileTool extends BaseTool<"read_file"> { /** * Process a text file according to the requested mode. + * + * Returns the content string plus whether that content is the complete + * file (S4b follow-up #46 / epic #1375): slice mode is complete only + * when it starts at line 1, returns every line, and was not truncated; + * indentation mode is never complete because it returns semantic blocks + * of the file, not the file itself. */ - private processTextFile(content: string, entry: InternalFileEntry): string { + private processTextFile(content: string, entry: InternalFileEntry): { content: string; complete: boolean } { const mode = entry.mode || "slice" if (mode === "indentation") { @@ -299,7 +328,8 @@ export class ReadFileTool extends BaseTool<"read_file"> { output += `\n\nIncluded ranges: ${rangeStr} (total: ${result.totalLines} lines)` } - return output + // Indentation mode returns semantic blocks: never a complete file view. + return { content: output, complete: false } } // Slice mode (default): simple offset/limit reading @@ -321,12 +351,33 @@ export class ReadFileTool extends BaseTool<"read_file"> { Status: Showing lines ${startLine}-${endLine} of ${result.totalLines} total lines. To read more: Use the read_file tool with offset=${nextOffset} and limit=${limit}. + ${result.content}` + if (result.hasClippedLines) { + // The slice cut lines off and also clipped long lines inside it, so both + // notices belong to the response. + output += `\nNote: Some lines in this view exceed ${MAX_LINE_LENGTH} characters and were clipped in this view.` + } + } else if (result.hasClippedLines) { + // Every line was returned, so there is no later offset to read: report the + // clipping without a next-offset hint, and keep the read incomplete so a + // full-file replacement cannot be built from a clipped line. + // A slice that starts past line 1 never showed the whole file, so the + // notice must not tell the model the file was read in full while the + // observation records it as incomplete. + const viewWasFull = offset0 === 0 + output = `IMPORTANT: Some lines exceed ${MAX_LINE_LENGTH} characters and were clipped in this view. ${viewWasFull ? "The file was read in full, but the clipped lines were not shown in full." : `The view starts at line ${offset0 + 1}, so lines 1-${offset0} were not shown and the file was not read in full.`} ${result.content}` } else if (result.returnedLines === 0) { output = "Note: File is empty" } - return output + // Complete only when the slice starts at line 1, returned every line, and + // showed every line in full (returnedLines === totalLines follows from the + // first two conditions): a partial start, a truncated tail, or a clipped + // line means the model did not see the whole file. + const complete = offset0 === 0 && !result.wasTruncated && !result.hasClippedLines + + return { content: output, complete } } /** @@ -768,9 +819,20 @@ export class ReadFileTool extends BaseTool<"read_file"> { } // Read text file - const rawContent = await fs.readFile(fullPath, "utf8") + // A2 (epic #1375): capture the on-disk token before the read so a mutation + // landing mid-read is detected by the post-read stat below. + const preReadStats = await fs.stat(fullPath, { bigint: true }).catch(() => undefined) + const rawBuffer = await fs.readFile(fullPath) + const rawContent = rawBuffer.toString("utf-8") + // Same contract: a lossy decode is a partial view. + const lossyDecode = !Buffer.from(rawContent).equals(rawBuffer) // Handle line ranges if specified + // S4b follow-up (#46 / epic #1375): a line-range read returns only the requested + // ranges, and a slice truncated to DEFAULT_LINE_LIMIT returns only the head of + // the file — record such observations as partial so the write guard denies a + // full-file update built on them. + let readComplete = false let content: string if (entry.lineRanges && entry.lineRanges.length > 0) { const lines = rawContent.split("\n") @@ -790,8 +852,16 @@ export class ReadFileTool extends BaseTool<"read_file"> { // Read with default limits using slice mode const result = readWithSlice(rawContent, 0, DEFAULT_LINE_LIMIT) content = result.content + readComplete = !result.wasTruncated && !result.hasClippedLines if (result.wasTruncated) { content += `\n\n[File truncated: showing ${result.returnedLines} of ${result.totalLines} total lines]` + if (result.hasClippedLines) { + // Both notices: the slice was truncated and a line inside it was + // clipped. + content += `\n\n[Some lines exceed the per-line length cap and were clipped in this view]` + } + } else if (result.hasClippedLines) { + content += `\n\n[Some lines exceed the per-line length cap and were clipped in this view]` } } @@ -799,6 +869,19 @@ export class ReadFileTool extends BaseTool<"read_file"> { // Track file in context await task.fileContextTracker.trackFileContext(relPath, "read_tool") + + // A2 (plan #33 / epic #1375): mirror the native path — record the observed + // on-disk version so legacy-format reads also feed the future write guard. + // Observe only when the pre-read and post-read tokens match (a mutation between + // them means the returned content is not the on-disk state). A stat failure + // leaves the target unobserved and never fails the read. + const postReadStats = await fs.stat(fullPath, { bigint: true }).catch(() => undefined) + if (preReadStats && postReadStats) { + const preReadToken = versionTokenOfStat(preReadStats) + if (preReadToken === versionTokenOfStat(postReadStats)) { + task.observationRegistry.observe(fullPath, preReadToken, readComplete && !lossyDecode) + } + } } catch (error) { const errorMsg = error instanceof Error ? error.message : String(error) results.push(`File: ${relPath}\nError: ${errorMsg}`) diff --git a/src/core/tools/__tests__/guardedWrite.spec.ts b/src/core/tools/__tests__/guardedWrite.spec.ts new file mode 100644 index 0000000000..414731cf6b --- /dev/null +++ b/src/core/tools/__tests__/guardedWrite.spec.ts @@ -0,0 +1,1235 @@ +/** + * Tests for the guarded-write compare-and-swap core (upstream epic #1375, + * phase A4a). + * + * Covers guard selection through the S2 observation registry, version-token + * CAS, remediation messages, and the per-absolute-path FIFO chain: FIFO + * ordering, last-write-wins for same-task writes through the post-publish + * observation refresh, no wedge after a rejected link, and independence across + * paths. + */ + +import * as fs from "fs/promises" +import type { BigIntStats } from "fs" +import * as path from "path" + +import { describe, expect, it, beforeEach, vi } from "vitest" + +import { createIfAbsent, guardedWrite, replaceIfVersion, resetChain, GuardRejectedError } from "../guardedWrite" +import { safeWriteText, TargetExistsError } from "../../../services/file-safety/safeWriteText" +import { computeVersionToken } from "../../../utils/versionToken" +import { withFileLock } from "../../../utils/fileLock" +import { resolveLockKey } from "../../../services/file-safety/safeWriteText" +import { ObservationRegistry } from "../../task/observationRegistry" +import type { Task } from "../../task/Task" + +// -- Mocks ------------------------------------------------------------------- + +vi.mock("fs/promises", () => ({ + access: vi.fn(), + stat: vi.fn(), + realpath: vi.fn(), + lstat: vi.fn(), +})) + +vi.mock("../../../utils/versionToken", () => ({ + computeVersionToken: vi.fn(), +})) + +vi.mock("../../../services/file-safety/safeWriteText", async (importOriginal) => { + // Keep the real error classes: guardedWrite compares the publish failure against + // TargetExistsError, so the identity has to be the production one. + const actual = await importOriginal() + return { + ...actual, + safeWriteText: vi.fn(), + resolveLockKey: vi.fn(async (p: string) => p), + } +}) + +vi.mock("../../../utils/fileLock", () => ({ + withFileLock: vi.fn(), +})) + +const mockedWithFileLock = vi.mocked(withFileLock) +const mockedResolveLockKey = vi.mocked(resolveLockKey) +const mockedFsAccess = vi.mocked(fs.access) +const mockedFsRealpath = vi.mocked(fs.realpath) +const mockedFsLstat = vi.mocked(fs.lstat) +const mockedFsStat = vi.mocked(fs.stat) +const mockedComputeVersionToken = vi.mocked(computeVersionToken) +const mockedSafeWriteText = vi.mocked(safeWriteText) + +// -- Fixtures ---------------------------------------------------------------- + +const WORKSPACE = "/test/workspace" + +/** Resolve a fixture path the same way guardedWrite resolves task.cwd-relative paths. */ +const abs = (relPath: string): string => path.resolve(WORKSPACE, relPath) + +interface MockTaskOptions { + cwd?: string + observationRegistry?: ObservationRegistry + abort?: boolean +} + +/** + * Minimal structural Task: guardedWrite only reads task.cwd and + * task.observationRegistry. The real Task constructor needs the full provider + * machinery, so a single documented double cast stands in for the class. + */ +/** + * BigIntStats double for the ancestor-identity pin. BigIntStats is class-backed with no + * public constructor and the guard reads only dev/ino, so this is a last-resort double + * assertion (test-local, per AGENTS.md). + */ +function dirStat(ino: bigint): BigIntStats { + return { dev: 1n, ino } as unknown as BigIntStats +} + +function createMockTask(options: MockTaskOptions = {}): Task { + const task = { + cwd: options.cwd ?? WORKSPACE, + abort: options.abort ?? false, + cancellationGeneration: 0, + observationRegistry: options.observationRegistry ?? new ObservationRegistry(), + } + return task as unknown as Task +} + +// -- Tests ------------------------------------------------------------------- + +describe("guardedWrite (S4a, epic #1375)", () => { + beforeEach(() => { + vi.resetAllMocks() + mockedWithFileLock.mockImplementation((filePath, operation) => operation(path.resolve(filePath))) + // The canonical containment check resolves the workspace first and REFUSES the + // write when the workspace cannot be resolved, so the default resolves every path + // to itself: the fixture workspace behaves like a real directory. The containment + // tests below override this to exercise the link cases. + mockedFsRealpath.mockImplementation(async (p) => String(p)) + // Nothing on the walked path is a symlink by default; the dangling-link test + // overrides this for the component it plants. + mockedFsLstat.mockRejectedValue(Object.assign(new Error("ENOENT"), { code: "ENOENT" })) + // By default no directory on the way to the target exists, so the ancestor + // identity pin is empty and the publish assertions stay readable. The pinning + // tests install real stats. + mockedFsStat.mockRejectedValue(Object.assign(new Error("ENOENT"), { code: "ENOENT" })) + resetChain() + }) + + describe("unobserved create", () => { + it("succeeds when the file is absent and publishes via safeWriteText", async () => { + mockedFsAccess.mockRejectedValue({ code: "ENOENT" }) + mockedComputeVersionToken.mockResolvedValue("v1") // post-publish refresh + const task = createMockTask() + + await guardedWrite(task, "new-file.txt", "hello", "create") + + expect(mockedSafeWriteText).toHaveBeenCalledTimes(1) + expect(mockedSafeWriteText).toHaveBeenCalledWith(abs("new-file.txt"), "hello", { failIfExist: true, expectedResolvedPath: abs("new-file.txt"), expectedAncestorIdentities: [] }) + }) + + it("publishes caller-supplied bytes unchanged", async () => { + // The extension host hands over bytes already encoded by VS Code's + // codec; the guard must pass them to the publish primitive as they are. + mockedFsAccess.mockRejectedValue({ code: "ENOENT" }) + mockedComputeVersionToken.mockResolvedValue("v1") // post-publish refresh + const task = createMockTask() + + await guardedWrite(task, "bytes.txt", Buffer.from([0x00, 0x68]), "create") + + expect(mockedSafeWriteText).toHaveBeenCalledWith(abs("bytes.txt"), Buffer.from([0x00, 0x68]), { failIfExist: true, expectedResolvedPath: abs("bytes.txt"), expectedAncestorIdentities: [] }) + }) + + it("records an unobserved create as complete so a later full-file update is allowed", async () => { + // Nothing was read, so the model supplied the whole file: the post-publish + // refresh must record completeness, otherwise the next update would be + // rejected as a partial read. + const reg = new ObservationRegistry() + mockedFsAccess.mockRejectedValue({ code: "ENOENT" }) + mockedComputeVersionToken.mockResolvedValue("v1") + const task = createMockTask({ observationRegistry: reg }) + + await guardedWrite(task, "new-file.txt", "hello", "create") + + expect(reg.get(abs("new-file.txt"))?.complete).toBe(true) + }) + + it("carries a caller-supplied completeness through the publish for a fresh destination", async () => { + // A move publishes content built from a view of another file. Recording the + // create as complete would hand the model authority over source lines it never + // read, so the caller's completeness has to survive the refresh. + const reg = new ObservationRegistry() + mockedFsAccess.mockRejectedValue({ code: "ENOENT" }) + mockedComputeVersionToken.mockResolvedValue("v1") + const task = createMockTask({ observationRegistry: reg }) + + await guardedWrite(task, "new-file.txt", "hello", "create", false) + + expect(reg.get(abs("new-file.txt"))?.complete).toBe(false) + }) + + it("fails with the read-first remediation when the file exists - nothing published", async () => { + mockedFsAccess.mockResolvedValue(undefined) + const task = createMockTask() + + await expect(guardedWrite(task, "existing.txt", "hello", "create")).rejects.toThrow( + "File already exists at " + + "existing.txt" + + " and was not read before this write -- read the file first, then retry.", + ) + expect(mockedSafeWriteText).not.toHaveBeenCalled() + }) + + it("refuses a create when the target appears between the absence check and the commit", async () => { + // The advisory lock only serializes writers that take it. A writer that never + // takes it can create the file after fs.access reported it absent, so the + // commit itself has to refuse: the no-replace link fails EEXIST and the guard + // turns that into the same read-first verdict the pre-check produces. + const task = createMockTask() + mockedFsAccess.mockRejectedValue({ code: "ENOENT" }) + mockedSafeWriteText.mockRejectedValueOnce(new TargetExistsError(abs("race.txt"))) + + await expect(guardedWrite(task, "race.txt", "hello", "create")).rejects.toThrow( + "File already exists at race.txt and was not read before this write -- read the file first, then retry.", + ) + + expect(mockedSafeWriteText).toHaveBeenCalledWith(abs("race.txt"), "hello", { + failIfExist: true, + expectedResolvedPath: abs("race.txt"), + expectedAncestorIdentities: [], + }) + }) + + it("rethrows I/O errors that are not ENOENT verbatim (no guard verdict on access failure)", async () => { + const failures = [{ code: "EACCES" }, null, "volume offline", new Error("EIO-ish failure")] + for (const failure of failures) { + mockedFsAccess.mockRejectedValueOnce(failure) + await expect(createIfAbsent(abs("io-error.txt"), "x", "io-error.txt")).rejects.toBe(failure) + } + expect(mockedSafeWriteText).not.toHaveBeenCalled() + }) + }) + + describe("deleted-after-read target", () => { + it("normalizes an ENOENT from the version token into the re-read remediation", async () => { + const reg = new ObservationRegistry() + reg.observe(abs("vanished.txt"), "v1") + const task = createMockTask({ observationRegistry: reg }) + + // The file was deleted after the read: the token computation fails + // with a raw ENOENT, which the guard must convert into the standard + // re-read-then-retry contract. + mockedComputeVersionToken.mockRejectedValue({ code: "ENOENT" }) + + await expect(guardedWrite(task, "vanished.txt", "next", "update")).rejects.toThrow( + "File was deleted after it was read", + ) + expect(mockedSafeWriteText).not.toHaveBeenCalled() + }) + + it("rethrows non-ENOENT token failures verbatim from replaceIfVersion", async () => { + const failure = { code: "EACCES" } + mockedComputeVersionToken.mockRejectedValueOnce(failure) + + await expect(replaceIfVersion(abs("locked.txt"), "v1", "next", "locked.txt")).rejects.toBe(failure) + expect(mockedSafeWriteText).not.toHaveBeenCalled() + }) + }) + describe("unobserved update", () => { + it("succeeds when the file is absent (same create guard)", async () => { + mockedFsAccess.mockRejectedValue({ code: "ENOENT" }) + mockedComputeVersionToken.mockResolvedValue("v1") // post-publish refresh + const task = createMockTask() + + await guardedWrite(task, "new-file.txt", "hello", "update") + + expect(mockedSafeWriteText).toHaveBeenCalledWith(abs("new-file.txt"), "hello", { failIfExist: true, expectedResolvedPath: abs("new-file.txt"), expectedAncestorIdentities: [] }) + }) + + it("fails with the read-first remediation when the file exists - nothing published", async () => { + mockedFsAccess.mockResolvedValue(undefined) + const task = createMockTask() + + await expect(guardedWrite(task, "existing.txt", "hello", "update")).rejects.toThrow( + "File already exists at " + + "existing.txt" + + " and was not read before this write -- read the file first, then retry.", + ) + expect(mockedSafeWriteText).not.toHaveBeenCalled() + }) + }) + + describe("workspace containment", () => { + it("rejects an absolute path outside the workspace before any lock or publish", async () => { + const task = createMockTask() + + await expect(guardedWrite(task, "/elsewhere/outside.txt", "data", "create")).rejects.toThrow( + "Path resolves outside the workspace", + ) + + // Nothing is queued, locked, or touched: the decision is made on the path + // alone, before the FIFO chain or the filesystem is involved. + expect(mockedWithFileLock).not.toHaveBeenCalled() + expect(mockedSafeWriteText).not.toHaveBeenCalled() + expect(mockedFsAccess).not.toHaveBeenCalled() + }) + + it("rejects a relative path that escapes the workspace through dot-dot", async () => { + const task = createMockTask() + + await expect(guardedWrite(task, "../outside.txt", "data", "create")).rejects.toThrow( + "Path resolves outside the workspace", + ) + + expect(mockedSafeWriteText).not.toHaveBeenCalled() + }) + + it("rejects a target whose resolved path leaves the workspace", async () => { + // The lexical check cannot see a link that lands outside. With the workspace + // resolvable, the canonical comparison is what rejects the write. + mockedFsRealpath.mockImplementation(async (p) => { + const s = String(p) + if (s === path.resolve(WORKSPACE)) { + return "/real/workspace" + } + return "/real/outside/secret.txt" + }) + const task = createMockTask() + + await expect(guardedWrite(task, "planted.txt", "data", "create")).rejects.toThrow( + "resolves through a link to outside the workspace", + ) + + expect(mockedSafeWriteText).not.toHaveBeenCalled() + }) + + + it("fails closed when the workspace itself cannot be resolved", async () => { + // EACCES/ELOOP on the workspace means a symlink inside it would never be resolved, so + // the containment decision cannot be made at all: the write is refused rather than + // falling back to the lexical-only check. + mockedFsRealpath.mockRejectedValue(Object.assign(new Error("EACCES"), { code: "EACCES" })) + const task = createMockTask() + + await expect(guardedWrite(task, "inside.txt", "data", "create")).rejects.toThrow( + "Workspace could not be resolved", + ) + + expect(mockedSafeWriteText).not.toHaveBeenCalled() + }) + + it("refuses a target that runs through a dangling symlink ancestor", async () => { + // A component of the path exists as a symlink whose referent is gone. realpath + // reports ENOENT for it, which is also what a not-yet-created directory + // reports; rejoining the lexical names would authorize a write whose publish + // lands outside the container that was checked. + const planted = path.join(path.resolve(WORKSPACE), "linkdir") + mockedFsRealpath.mockImplementation(async (p) => { + const s = String(p) + if (s === path.resolve(WORKSPACE)) return path.resolve(WORKSPACE) + throw Object.assign(new Error("ENOENT"), { code: "ENOENT" }) + }) + mockedFsLstat.mockImplementation(async (p) => { + if (String(p) === planted) { + return { isSymbolicLink: () => true } as never + } + throw Object.assign(new Error("ENOENT"), { code: "ENOENT" }) + }) + const task = createMockTask() + + await expect(guardedWrite(task, "linkdir/nested/new.txt", "data", "create")).rejects.toThrow( + "runs through a link", + ) + + expect(mockedSafeWriteText).not.toHaveBeenCalled() + }) + + it("authorizes a create under an aliased ancestor and pins the publish's own spelling", async () => { + // The macOS /var -> /private/var shape: the workspace resolves through a link, and + // the directory the create lands in does not exist yet. Both the containment check + // and the publish primitive canonicalize through the nearest existing ancestor, so + // the write must proceed and the pin must be the SAME canonical spelling the + // publish computes for itself - two spellings of one file would make the pin + // reject a write that was just authorized. + const canonicalRoot = "/real/workspace" + mockedFsRealpath.mockImplementation(async (p) => { + const s = String(p) + if (s === path.resolve(WORKSPACE)) return canonicalRoot + throw Object.assign(new Error("ENOENT"), { code: "ENOENT" }) + }) + mockedFsAccess.mockRejectedValue({ code: "ENOENT" }) + mockedComputeVersionToken.mockResolvedValue("v1") + const task = createMockTask() + + await guardedWrite(task, "linkdir/new.txt", "data", "create") + + expect(mockedSafeWriteText).toHaveBeenCalledTimes(1) + const options = mockedSafeWriteText.mock.calls[0][2] as Record + // path.join, not a literal: the canonical spelling is joined the same way the + // guard and the publish both join it. + expect(options.expectedResolvedPath).toBe(path.join(canonicalRoot, "linkdir", "new.txt")) + // No TargetMovedError, no refusal: the guard and the publish agree on the + // canonical spelling of the file they are about to write. + expect(mockedSafeWriteText.mock.calls[0][0]).toBe(abs("linkdir/new.txt")) + }) + + it("re-checks containment under the lock, after the wait on the FIFO chain", async () => { + // The path was inside the workspace when it was queued; a link is swapped in while the + // write waits. The publish must not follow the new link. + let targetLookups = 0 + mockedFsRealpath.mockImplementation(async (p) => { + const s = String(p) + if (s === path.resolve(WORKSPACE)) { + return "/real/workspace" + } + targetLookups++ + return targetLookups === 1 ? "/real/workspace/in.txt" : "/real/outside/secret.txt" + }) + mockedFsAccess.mockRejectedValue({ code: "ENOENT" }) + const task = createMockTask() + + await expect(guardedWrite(task, "in.txt", "data", "create")).rejects.toThrow( + "resolves through a link to outside the workspace", + ) + + expect(targetLookups).toBeGreaterThan(1) + expect(mockedSafeWriteText).not.toHaveBeenCalled() + }) + it("publishes when the resolved path stays inside the workspace", async () => { + mockedFsRealpath.mockImplementation(async (p) => { + const s = String(p) + if (s === path.resolve(WORKSPACE)) { + return "/real/workspace" + } + return "/real/workspace/nested/in.txt" + }) + mockedFsAccess.mockRejectedValue({ code: "ENOENT" }) + mockedComputeVersionToken.mockResolvedValue("v1") + const task = createMockTask() + + await guardedWrite(task, "nested/in.txt", "data", "create") + + expect(mockedSafeWriteText).toHaveBeenCalledWith(abs("nested/in.txt"), "data", { + failIfExist: true, + // The canonical target the containment check authorized is pinned onto the + // publish, so a link swapped in afterwards cannot redirect it. + expectedResolvedPath: "/real/workspace/nested/in.txt", + // No ancestor is pinned here: the fixture stat reports "not on disk". + expectedAncestorIdentities: [], + }) + }) + + it("refuses a write when the workspace is missing from disk, instead of falling back to the lexical check", async () => { + // ENOENT on the workspace used to fall through to the lexical-only decision - the + // exact decision a symlink defeats. With no canonical root there is nothing to + // contain the write in, so the write is refused rather than published on a weaker + // guarantee. + mockedFsRealpath.mockRejectedValue(Object.assign(new Error("ENOENT"), { code: "ENOENT" })) + const task = createMockTask() + + await expect(guardedWrite(task, "inside.txt", "data", "create")).rejects.toThrow( + "Workspace could not be resolved", + ) + + expect(mockedSafeWriteText).not.toHaveBeenCalled() + }) + + it("pins the identity of every existing directory between the workspace root and the target", async () => { + // expectedResolvedPath pins the NAME that gets published. The pin below is what + // lets the publish notice that the directory the name sits in is no longer the + // directory that was authorized. + mockedFsAccess.mockRejectedValue({ code: "ENOENT" }) + mockedComputeVersionToken.mockResolvedValue("v1") + mockedFsStat.mockImplementation(async (p) => { + const dir = String(p) + if (dir === path.resolve(WORKSPACE)) return dirStat(100n) + if (dir === abs("nested")) return dirStat(200n) + throw Object.assign(new Error("ENOENT"), { code: "ENOENT" }) + }) + const task = createMockTask() + + await guardedWrite(task, "nested/in.txt", "data", "create") + + expect(mockedSafeWriteText).toHaveBeenCalledWith(abs("nested/in.txt"), "data", { + failIfExist: true, + expectedResolvedPath: abs("nested/in.txt"), + expectedAncestorIdentities: [ + { dir: path.resolve(WORKSPACE), dev: 1n, ino: 100n }, + { dir: abs("nested"), dev: 1n, ino: 200n }, + ], + }) + }) + + it("refuses the publish when an authorized parent directory is swapped after the containment check", async () => { + // The target name and its resolved path are unchanged, so expectedResolvedPath + // still matches; what changed is the directory the name lives in - it was replaced + // by another directory (a link to outside the workspace looks exactly like this). + // The recorded identities are what catch it, and nothing is published. + mockedFsAccess.mockRejectedValue({ code: "ENOENT" }) + let statCalls = 0 + mockedFsStat.mockImplementation(async (p) => { + statCalls++ + // First pass (the pre-queue check) sees the authorized directories; the + // second pass (under the lock, before the publish) sees a replaced parent. + const replaced = statCalls > 2 + const dir = String(p) + if (dir === path.resolve(WORKSPACE)) return dirStat(100n) + if (dir === abs("nested")) return dirStat(replaced ? 999n : 200n) + throw Object.assign(new Error("ENOENT"), { code: "ENOENT" }) + }) + const task = createMockTask() + + await expect(guardedWrite(task, "nested/in.txt", "data", "create")).rejects.toThrow( + "A directory on the authorized path was replaced after this write was checked", + ) + + expect(statCalls).toBeGreaterThan(2) + expect(mockedSafeWriteText).not.toHaveBeenCalled() + }) + + it("refuses an already-cancelled task before any containment work starts", async () => { + // The cancellation verdict must be reached before the first await, so a write for + // a task that is already gone does not touch the filesystem at all. + const task = createMockTask({ abort: true }) + mockedFsAccess.mockRejectedValue({ code: "ENOENT" }) + + await expect(guardedWrite(task, "new-file.txt", "data", "create")).rejects.toThrow( + "Task was cancelled before this write ran -- the queued publish is not performed.", + ) + + expect(mockedFsRealpath).not.toHaveBeenCalled() + expect(mockedSafeWriteText).not.toHaveBeenCalled() + }) + + it("refuses a write cancelled while the pre-publish containment check is in flight", async () => { + // The containment check awaits. A cancel that lands inside that await, followed by + // a resume, must not be invisible: capturing the generation after the await would + // record the POST-cancel generation, the dequeue comparison would pass, and the + // cancelled run's content would publish. + const task = createMockTask() + mockedFsAccess.mockRejectedValue({ code: "ENOENT" }) + let release!: () => void + const gate = new Promise((resolve) => { + release = resolve + }) + let targetLookups = 0 + mockedFsRealpath.mockImplementation(async (p) => { + const s = String(p) + if (s === path.resolve(WORKSPACE)) return s + targetLookups++ + if (targetLookups === 1) { + task.abort = true + task.cancellationGeneration++ + task.abort = false + await gate + } + return s + }) + + const write = guardedWrite(task, "in.txt", "data", "create") + await new Promise((resolve) => setTimeout(resolve, 0)) + release() + + await expect(write).rejects.toThrow( + "Task was cancelled before this write ran -- the queued publish is not performed.", + ) + expect(mockedSafeWriteText).not.toHaveBeenCalled() + }) + }) + + describe("observed create", () => { + it("recreates a file that vanished after the read", async () => { + const reg = new ObservationRegistry() + reg.observe(abs("gone.txt"), "v1") + mockedFsAccess.mockRejectedValue({ code: "ENOENT" }) + mockedComputeVersionToken.mockResolvedValue("v1") // post-publish refresh + const task = createMockTask({ observationRegistry: reg }) + + await guardedWrite(task, "gone.txt", "back", "create") + + expect(mockedSafeWriteText).toHaveBeenCalledTimes(1) + expect(mockedSafeWriteText).toHaveBeenCalledWith(abs("gone.txt"), "back", { failIfExist: true, expectedResolvedPath: abs("gone.txt"), expectedAncestorIdentities: [] }) + }) + + it("goes through the version guard when the file still exists", async () => { + const reg = new ObservationRegistry() + reg.observe(abs("kept.txt"), "v1") + mockedFsAccess.mockResolvedValue(undefined) + mockedComputeVersionToken.mockResolvedValue("v1") + const task = createMockTask({ observationRegistry: reg }) + + await guardedWrite(task, "kept.txt", "rewritten", "create") + + expect(mockedSafeWriteText).toHaveBeenCalledWith(abs("kept.txt"), "rewritten", { expectedResolvedPath: abs("kept.txt"), expectedAncestorIdentities: [] }) + }) + + it("fails with the stale remediation suffix when the version moved", async () => { + const reg = new ObservationRegistry() + reg.observe(abs("kept.txt"), "v1") + mockedFsAccess.mockResolvedValue(undefined) + mockedComputeVersionToken.mockResolvedValue("v2") + const task = createMockTask({ observationRegistry: reg }) + + await expect(guardedWrite(task, "kept.txt", "rewritten", "create")).rejects.toThrow( + "Stale version -- the file changed since you read it (expected v1, current v2); re-read the file, then retry.", + ) + expect(mockedSafeWriteText).not.toHaveBeenCalled() + }) + + it("defers to the version guard when the access check is denied (not ENOENT)", async () => { + const reg = new ObservationRegistry() + reg.observe(abs("locked.txt"), "v1") + mockedFsAccess.mockRejectedValue({ code: "EACCES" }) + mockedComputeVersionToken.mockResolvedValue("v2") + const task = createMockTask({ observationRegistry: reg }) + + await expect(guardedWrite(task, "locked.txt", "rewritten", "create")).rejects.toThrow( + "Stale version -- the file changed since you read it (expected v1, current v2); re-read the file, then retry.", + ) + expect(mockedSafeWriteText).not.toHaveBeenCalled() + }) + }) + + describe("observed update (version CAS)", () => { + it("publishes when the on-disk version matches the observation", async () => { + const reg = new ObservationRegistry() + reg.observe(abs("doc.txt"), "v1") + mockedComputeVersionToken.mockResolvedValue("v1") + const task = createMockTask({ observationRegistry: reg }) + + await guardedWrite(task, "doc.txt", "new content", "update") + + expect(mockedComputeVersionToken).toHaveBeenCalledWith(abs("doc.txt")) + expect(mockedSafeWriteText).toHaveBeenCalledWith(abs("doc.txt"), "new content", { expectedResolvedPath: abs("doc.txt"), expectedAncestorIdentities: [] }) + }) + + it("fails with the stale remediation suffix when the version moved - nothing published", async () => { + const reg = new ObservationRegistry() + reg.observe(abs("doc.txt"), "v1") + mockedComputeVersionToken.mockResolvedValue("v2") + const task = createMockTask({ observationRegistry: reg }) + + await expect(guardedWrite(task, "doc.txt", "new content", "update")).rejects.toThrow( + "Stale version -- the file changed since you read it (expected v1, current v2); re-read the file, then retry.", + ) + expect(mockedSafeWriteText).not.toHaveBeenCalled() + }) + }) + + describe("observed update (read completeness, S4b follow-up #46)", () => { + it("rejects a full-file update when only a partial read observed the file - no I/O, nothing published", async () => { + const reg = new ObservationRegistry() + reg.observe(abs("doc.txt"), "v1", false) + mockedComputeVersionToken.mockResolvedValue("v1") + const task = createMockTask({ observationRegistry: reg }) + + await expect(guardedWrite(task, "doc.txt", "new content", "update")).rejects.toThrow( + "File was only partially read (line slice, range, truncated view, or indentation block) -- " + + "a full-file replacement needs the complete content; re-read the whole file, then retry.", + ) + expect(mockedSafeWriteText).not.toHaveBeenCalled() + expect(mockedComputeVersionToken).not.toHaveBeenCalled() + expect(mockedFsAccess).not.toHaveBeenCalled() + }) + + it("publishes a full-file update when the observation is complete and the version matches", async () => { + const reg = new ObservationRegistry() + reg.observe(abs("doc.txt"), "v1", true) + mockedComputeVersionToken.mockResolvedValue("v1") + const task = createMockTask({ observationRegistry: reg }) + + await guardedWrite(task, "doc.txt", "new content", "update") + + expect(mockedSafeWriteText).toHaveBeenCalledWith(abs("doc.txt"), "new content", { expectedResolvedPath: abs("doc.txt"), expectedAncestorIdentities: [] }) + }) + + it("leaves edit-kind publishes unaffected by a partial observation - the model saw the edited region", async () => { + const reg = new ObservationRegistry() + reg.observe(abs("doc.txt"), "v1", false) + mockedComputeVersionToken.mockResolvedValue("v1") + const task = createMockTask({ observationRegistry: reg }) + + await guardedWrite(task, "doc.txt", "patched", "edit") + + expect(mockedSafeWriteText).toHaveBeenCalledWith(abs("doc.txt"), "patched", { expectedResolvedPath: abs("doc.txt"), expectedAncestorIdentities: [] }) + }) + + it("keeps a partial observation partial after an edit so a later full replacement is rejected", async () => { + // The edit replaced only the region the model saw. Refreshing the + // observation to complete would let a following full-file write publish + // content built from the slice alone. + const reg = new ObservationRegistry() + reg.observe(abs("doc.txt"), "v1", false) + mockedComputeVersionToken.mockResolvedValue("v1") + const task = createMockTask({ observationRegistry: reg }) + + await guardedWrite(task, "doc.txt", "patched", "edit") + + expect(reg.get(abs("doc.txt"))?.complete).toBe(false) + + await expect(guardedWrite(task, "doc.txt", "full replacement", "update")).rejects.toThrow( + "File was only partially read (line slice, range, truncated view, or indentation block) -- " + + "a full-file replacement needs the complete content; re-read the whole file, then retry.", + ) + }) + + it("rejects a create-kind full-file overwrite of an existing file when only a partial read observed it", async () => { + const reg = new ObservationRegistry() + reg.observe(abs("doc.txt"), "v1", false) + mockedFsAccess.mockResolvedValue(undefined) // target still on disk + const task = createMockTask({ observationRegistry: reg }) + + // A "create" whose target exists publishes through the same + // full-file replacement path as "update": a partial observation must + // not authorize dropping the content the model never read. + await expect(guardedWrite(task, "doc.txt", "created", "create")).rejects.toThrow( + "File was only partially read (line slice, range, truncated view, or indentation block) -- " + + "a full-file replacement needs the complete content; re-read the whole file, then retry.", + ) + expect(mockedSafeWriteText).not.toHaveBeenCalled() + expect(mockedComputeVersionToken).not.toHaveBeenCalled() + }) + + it("allows a create-kind recreate of a vanished file despite a partial observation - a fresh create needs no prior read", async () => { + const reg = new ObservationRegistry() + reg.observe(abs("doc.txt"), "v1", false) + mockedFsAccess.mockRejectedValue({ code: "ENOENT" }) // target absent + mockedComputeVersionToken.mockResolvedValue("v1") // post-publish refresh + const task = createMockTask({ observationRegistry: reg }) + + await guardedWrite(task, "doc.txt", "created", "create") + + expect(mockedSafeWriteText).toHaveBeenCalledWith(abs("doc.txt"), "created", { failIfExist: true, expectedResolvedPath: abs("doc.txt"), expectedAncestorIdentities: [] }) + }) + + it("publishes a create-kind overwrite of an existing file when the observation is complete", async () => { + const reg = new ObservationRegistry() + reg.observe(abs("doc.txt"), "v1") + mockedFsAccess.mockResolvedValue(undefined) // target still on disk + mockedComputeVersionToken.mockResolvedValue("v1") + const task = createMockTask({ observationRegistry: reg }) + + await guardedWrite(task, "doc.txt", "created", "create") + + expect(mockedSafeWriteText).toHaveBeenCalledWith(abs("doc.txt"), "created", { expectedResolvedPath: abs("doc.txt"), expectedAncestorIdentities: [] }) + }) + }) + + describe("observation refresh after publish (S4b review round)", () => { + it("refreshes the observation with the post-publish token so a consecutive edit does not fail stale", async () => { + const reg = new ObservationRegistry() + reg.observe(abs("doc.txt"), "v1") + const task = createMockTask({ observationRegistry: reg }) + // The first publish moves the on-disk token: edit 1's pre-write CAS + // sees v1, the post-publish refresh sees v2, and edit 2's CAS sees v2. + mockedComputeVersionToken.mockResolvedValueOnce("v1").mockResolvedValueOnce("v2").mockResolvedValue("v2") + + await guardedWrite(task, "doc.txt", "first edit", "edit") + await guardedWrite(task, "doc.txt", "second edit", "edit") + + expect(mockedSafeWriteText).toHaveBeenCalledTimes(2) + expect(mockedSafeWriteText).toHaveBeenLastCalledWith(abs("doc.txt"), "second edit", { expectedResolvedPath: abs("doc.txt"), expectedAncestorIdentities: [] }) + // the observation now carries the post-publish token, complete + expect(reg.get(abs("doc.txt"))?.version).toBe("v2") + expect(reg.get(abs("doc.txt"))?.complete).toBe(true) + }) + + it("refreshes as a COMPLETE observation so a consecutive full-file update is not rejected partial", async () => { + const reg = new ObservationRegistry() + reg.observe(abs("doc.txt"), "v1") + const task = createMockTask({ observationRegistry: reg }) + mockedComputeVersionToken + .mockResolvedValueOnce("v1") // update 1 pre-write CAS + .mockResolvedValueOnce("v2") // update 1 post-publish refresh + .mockResolvedValue("v2") // update 2 pre-write CAS + + await guardedWrite(task, "doc.txt", "first", "update") + await guardedWrite(task, "doc.txt", "second", "update") + + // a refresh recorded as partial would have the second update + // rejected by the completeness gate + expect(mockedSafeWriteText).toHaveBeenCalledTimes(2) + expect(reg.get(abs("doc.txt"))?.complete).toBe(true) + }) + + it("keeps the previous observation when the post-publish token cannot be computed (deletion race after publish)", async () => { + const reg = new ObservationRegistry() + reg.observe(abs("doc.txt"), "v1") + const task = createMockTask({ observationRegistry: reg }) + // The publish succeeded but the file was deleted before the refresh + // stat: the token computation rejects (ENOENT) and the guard's + // .catch normalizes it to undefined. The observation must keep the + // pre-publish version (the next write fails closed through the + // standard deleted/stale path) rather than a token-less record. + mockedComputeVersionToken + .mockResolvedValueOnce("v1") // edit 1 pre-write CAS + .mockRejectedValueOnce({ code: "ENOENT" }) // edit 1 post-publish refresh - file deleted + .mockResolvedValue("v1") // edit 2 pre-write CAS + + await guardedWrite(task, "doc.txt", "first edit", "edit") + await guardedWrite(task, "doc.txt", "second edit", "edit") + + expect(mockedSafeWriteText).toHaveBeenCalledTimes(2) + expect(reg.get(abs("doc.txt"))?.version).toBe("v1") + }) + }) + + describe("edit", () => { + it("fails read-first when the file was never observed - nothing published, no I/O", async () => { + const task = createMockTask() + + await expect(guardedWrite(task, "any.txt", "patched", "edit")).rejects.toThrow( + "File not read yet -- read the file, then retry.", + ) + expect(mockedSafeWriteText).not.toHaveBeenCalled() + expect(mockedComputeVersionToken).not.toHaveBeenCalled() + expect(mockedFsAccess).not.toHaveBeenCalled() + }) + + it("publishes when the version matches the observation", async () => { + const reg = new ObservationRegistry() + reg.observe(abs("doc.txt"), "v1") + mockedComputeVersionToken.mockResolvedValue("v1") + const task = createMockTask({ observationRegistry: reg }) + + await guardedWrite(task, "doc.txt", "patched", "edit") + + expect(mockedSafeWriteText).toHaveBeenCalledWith(abs("doc.txt"), "patched", { expectedResolvedPath: abs("doc.txt"), expectedAncestorIdentities: [] }) + }) + + it("fails with the stale remediation suffix when the version moved", async () => { + const reg = new ObservationRegistry() + reg.observe(abs("doc.txt"), "v1") + mockedComputeVersionToken.mockResolvedValue("v3") + const task = createMockTask({ observationRegistry: reg }) + + await expect(guardedWrite(task, "doc.txt", "patched", "edit")).rejects.toThrow( + "Stale version -- the file changed since you read it (expected v1, current v3); re-read the file, then retry.", + ) + expect(mockedSafeWriteText).not.toHaveBeenCalled() + }) + }) + + describe("concurrency: per-path FIFO chain", () => { + it("two concurrent updates on one path - serialized, both publish against the refreshed observation", async () => { + const reg = new ObservationRegistry() + reg.observe(abs("shared.txt"), "v1") + mockedComputeVersionToken.mockResolvedValue("v1") + const task = createMockTask({ observationRegistry: reg }) + + // The first publish changes the on-disk state (new token), and the + // guarded write refreshes the observation to it, so the second + // write CASes against v2 and publishes too: same-task writes are + // serialized last-write-wins in submission order, while a token that + // moves outside the task's own publish still fails stale. + mockedSafeWriteText.mockImplementation(async () => { + mockedComputeVersionToken.mockResolvedValue("v2") + }) + + const p1 = guardedWrite(task, "shared.txt", "first", "update") + const p2 = guardedWrite(task, "shared.txt", "second", "update") + const [r1, r2] = await Promise.allSettled([p1, p2]) + + expect(r1.status).toBe("fulfilled") + expect(r2.status).toBe("fulfilled") + expect(mockedSafeWriteText).toHaveBeenCalledTimes(2) + expect(mockedSafeWriteText).toHaveBeenNthCalledWith(1, abs("shared.txt"), "first", { expectedResolvedPath: abs("shared.txt"), expectedAncestorIdentities: [] }) + expect(mockedSafeWriteText).toHaveBeenNthCalledWith(2, abs("shared.txt"), "second", { expectedResolvedPath: abs("shared.txt"), expectedAncestorIdentities: [] }) + }) + + it("observed-absent then two concurrent creates - the second publishes against the refreshed observation", async () => { + const reg = new ObservationRegistry() + reg.observe(abs("absent.txt"), "v1") // read before, file later vanished + mockedFsAccess.mockRejectedValue({ code: "ENOENT" }) + const task = createMockTask({ observationRegistry: reg }) + + let publishes = 0 + mockedSafeWriteText.mockImplementation(async () => { + publishes += 1 + if (publishes === 1) { + // After the first publish the file exists again under a new + // token, and the guarded write refreshes the observation to it. + mockedFsAccess.mockResolvedValue(undefined) + mockedComputeVersionToken.mockResolvedValue("v2") + } + }) + + const p1 = guardedWrite(task, "absent.txt", "first", "create") + const p2 = guardedWrite(task, "absent.txt", "second", "create") + const [r1, r2] = await Promise.allSettled([p1, p2]) + + // Both same-task creates serialize: the second CASes against the + // refreshed v2 observation and publishes its content last-write-wins. + expect(r1.status).toBe("fulfilled") + expect(r2.status).toBe("fulfilled") + expect(publishes).toBe(2) + expect(mockedSafeWriteText).toHaveBeenNthCalledWith(1, abs("absent.txt"), "first", { failIfExist: true, expectedResolvedPath: abs("absent.txt"), expectedAncestorIdentities: [] }) + expect(mockedSafeWriteText).toHaveBeenNthCalledWith(2, abs("absent.txt"), "second", { expectedResolvedPath: abs("absent.txt"), expectedAncestorIdentities: [] }) + }) + + it("the chain settles after a rejection - a later matching write still runs", async () => { + const reg = new ObservationRegistry() + reg.observe(abs("settle.txt"), "v1") + mockedComputeVersionToken.mockResolvedValue("v2") // already stale at v1 + const task = createMockTask({ observationRegistry: reg }) + + const p1 = guardedWrite(task, "settle.txt", "first", "update") + await expect(p1).rejects.toThrow("Stale version") + + // No resetChain: the rejected link must not wedge the chain. The + // caller re-reads the file (observation refreshed to v2) and retries. + reg.observe(abs("settle.txt"), "v2") + const p2 = guardedWrite(task, "settle.txt", "second", "update") + await expect(p2).resolves.toBeUndefined() + + expect(mockedSafeWriteText).toHaveBeenCalledTimes(1) + expect(mockedSafeWriteText).toHaveBeenCalledWith(abs("settle.txt"), "second", { expectedResolvedPath: abs("settle.txt"), expectedAncestorIdentities: [] }) + }) + + it("evicts settled chain entries - a later write still serializes in order", async () => { + const reg = new ObservationRegistry() + reg.observe(abs("evict.txt"), "v1") + mockedComputeVersionToken.mockResolvedValue("v1") + const task = createMockTask({ observationRegistry: reg }) + + // A first write settles; its chain entry is evicted with it. + const p1 = guardedWrite(task, "evict.txt", "first", "update") + await expect(p1).resolves.toBeUndefined() + + // Two rapid writes submitted after the eviction must still run one + // at a time in submission order (the eviction must not drop the + // chain for in-flight or just-enqueued links). + const order: (string | Uint8Array)[] = [] + mockedSafeWriteText.mockImplementation(async (_path: string, content: string | Uint8Array) => { + order.push(content) + }) + const p2 = guardedWrite(task, "evict.txt", "second", "update") + const p3 = guardedWrite(task, "evict.txt", "third", "update") + await Promise.all([p2, p3]) + + expect(order).toEqual(["second", "third"]) + // Three publishes in total: the settled first write plus the two + // serialized rapid writes. + expect(mockedSafeWriteText).toHaveBeenCalledTimes(3) + }) + + it("writes on different paths are independent (no cross-path serialization)", async () => { + const reg = new ObservationRegistry() + reg.observe(abs("a.txt"), "v1") + reg.observe(abs("b.txt"), "v1") + mockedComputeVersionToken.mockResolvedValue("v1") + const task = createMockTask({ observationRegistry: reg }) + + const p1 = guardedWrite(task, "a.txt", "a", "update") + const p2 = guardedWrite(task, "b.txt", "b", "update") + await Promise.all([p1, p2]) + + expect(mockedSafeWriteText).toHaveBeenCalledTimes(2) + }) + }) + + describe("path resolution", () => { + it("resolves a relative path against task.cwd", async () => { + const reg = new ObservationRegistry() + reg.observe(abs("sub/dir.txt"), "v1") + mockedComputeVersionToken.mockResolvedValue("v1") + const task = createMockTask({ observationRegistry: reg }) + + await guardedWrite(task, "sub/dir.txt", "content", "update") + + expect(mockedSafeWriteText).toHaveBeenCalledWith(abs("sub/dir.txt"), "content", { expectedResolvedPath: abs("sub/dir.txt"), expectedAncestorIdentities: [] }) + }) + + it("normalizes an already-absolute input (trailing separator) to the observation key", async () => { + const reg = new ObservationRegistry() + const canonical = abs("sub/dir.txt") + // ReadFileTool observes under path.resolve(task.cwd, relPath) — the + // canonical spelling. A write addressed with a trailing separator used + // to bypass the observation (isAbsolute passthrough) and fail + // "File already exists" / "File not read yet" for a file that was read. + reg.observe(canonical, "v1") + mockedComputeVersionToken.mockResolvedValue("v1") + const task = createMockTask({ observationRegistry: reg }) + + await guardedWrite(task, canonical + "/", "content", "update") + + expect(mockedSafeWriteText).toHaveBeenCalledTimes(1) + expect(mockedSafeWriteText).toHaveBeenCalledWith(canonical, "content", { expectedResolvedPath: canonical, expectedAncestorIdentities: [] }) + }) + + it("serializes two spellings of one file through a single chain key", async () => { + const reg = new ObservationRegistry() + const canonical = abs("shared2.txt") + reg.observe(canonical, "v1") + mockedComputeVersionToken.mockResolvedValue("v1") + const task = createMockTask({ observationRegistry: reg }) + + // The first publish changes the on-disk state (new token). + mockedSafeWriteText.mockImplementation(async () => { + mockedComputeVersionToken.mockResolvedValue("v2") + }) + + // Plain spelling vs the trailing-separator spelling: with one chain + // key they are strictly ordered. The first matches v1 and publishes; + // its post-publish refresh records v2, so the second CASes against + // v2 and publishes too (serialized same-task writes). + const p1 = guardedWrite(task, canonical, "first", "update") + const p2 = guardedWrite(task, canonical + "/", "second", "update") + const [r1, r2] = await Promise.allSettled([p1, p2]) + + expect(r1.status).toBe("fulfilled") + expect(r2.status).toBe("fulfilled") + expect(mockedSafeWriteText).toHaveBeenCalledTimes(2) + expect(mockedSafeWriteText).toHaveBeenNthCalledWith(1, canonical, "first", { expectedResolvedPath: canonical, expectedAncestorIdentities: [] }) + expect(mockedSafeWriteText).toHaveBeenNthCalledWith(2, canonical, "second", { expectedResolvedPath: canonical, expectedAncestorIdentities: [] }) + }) + }) + + describe("lock serialization with other writers", () => { + it("holds the shared advisory lock across the version check and the publish", async () => { + // The guard decision and the publish must be one operation under the same + // advisory lock that safeWriteJson and task-history deletion use, otherwise + // a lock-using writer can land between the check and the write. + const order: string[] = [] + mockedWithFileLock.mockImplementation(async (filePath, operation) => { + order.push("lock") + const result = await operation(path.resolve(filePath)) + order.push("release") + return result + }) + mockedComputeVersionToken.mockImplementation(async () => { + order.push("check") + return "v1" + }) + mockedSafeWriteText.mockImplementation(async () => { + order.push("publish") + }) + + await replaceIfVersion(abs("a.txt"), "v1", "content", "a.txt") + + expect(order).toEqual(["lock", "check", "publish", "check", "release"]) + expect(mockedWithFileLock).toHaveBeenCalledWith(abs("a.txt"), expect.any(Function)) + }) + + it("holds the same lock across the absence check and the publish for an unobserved create", async () => { + const order: string[] = [] + mockedWithFileLock.mockImplementation(async (filePath, operation) => { + order.push("lock") + const result = await operation(path.resolve(filePath)) + order.push("release") + return result + }) + mockedFsAccess.mockImplementation(async () => { + order.push("check") + throw { code: "ENOENT" } + }) + mockedSafeWriteText.mockImplementation(async () => { + order.push("publish") + }) + + mockedComputeVersionToken.mockImplementation(async () => { + order.push("token") + return "v1" + }) + + await createIfAbsent(abs("new.txt"), "hello", "new.txt") + + expect(order).toEqual(["lock", "check", "publish", "token", "release"]) + }) + + it("locks the resolved publish target instead of the link path", async () => { + // proper-lockfile keys by the path it is given, so a symlink alias and its + // referent would take two locks for one file. The guard must lock the key + // every other writer to that file uses. + const referent = abs("real/file.txt") + mockedResolveLockKey.mockResolvedValue(referent) + mockedFsAccess.mockRejectedValue({ code: "ENOENT" }) + mockedComputeVersionToken.mockResolvedValue("v1") + + await createIfAbsent(abs("link.txt"), "hello", "link.txt") + + expect(mockedResolveLockKey).toHaveBeenCalledWith(abs("link.txt")) + expect(mockedWithFileLock).toHaveBeenCalledWith(referent, expect.any(Function)) + }) + + it("reads the post-publish token inside the lock, before releasing it", async () => { + // A peer lock-using writer can publish in the gap between the publish and + // a post-publish stat made after the lock is released, and the task would + // then record that peer's token as its own observation. + const order: string[] = [] + mockedWithFileLock.mockImplementation(async (filePath, operation) => { + order.push("lock") + const result = await operation(path.resolve(filePath)) + order.push("release") + return result + }) + mockedComputeVersionToken.mockImplementation(async () => { + order.push("check") + return "v1" + }) + mockedSafeWriteText.mockImplementation(async () => { + order.push("publish") + return undefined + }) + + const token = await replaceIfVersion(abs("a.txt"), "v1", "content", "a.txt") + + expect(order).toEqual(["lock", "check", "publish", "check", "release"]) + expect(token).toBe("v1") + }) + }) + + describe("resetChain", () => { + it("detaches pending links so later writes start a fresh chain", async () => { + const reg = new ObservationRegistry() + reg.observe(abs("x.txt"), "v1") + mockedComputeVersionToken.mockResolvedValue("v1") + const task = createMockTask({ observationRegistry: reg }) + + await guardedWrite(task, "x.txt", "a", "update") + resetChain() + await guardedWrite(task, "x.txt", "b", "update") + + expect(mockedSafeWriteText).toHaveBeenLastCalledWith(abs("x.txt"), "b", { expectedResolvedPath: abs("x.txt"), expectedAncestorIdentities: [] }) + }) + }) + + it("does not run a queued write once the owning task is cancelled", async () => { + const task = createMockTask({ abort: true }) + mockedFsAccess.mockRejectedValue({ code: "ENOENT" }) + + await expect(guardedWrite(task, "new-file.txt", "hello", "create")).rejects.toThrow( + "Task was cancelled before this write ran -- the queued publish is not performed.", + ) + + expect(mockedSafeWriteText).not.toHaveBeenCalled() + }) + + it("refuses a queued write whose task was cancelled and resumed before its turn", async () => { + // A write parks on the path chain behind another write for a different task, so it + // has not reached its own checks yet. Its task is then cancelled and resumed: by the + // time the link dequeues, abort is back to false, and the flag alone cannot tell the + // write that it belongs to the cancelled run. The captured generation can. + const blocker = createMockTask() + const cancelled = createMockTask() + mockedComputeVersionToken.mockResolvedValue("v1") // post-publish refresh + let releaseCheck!: () => void + const gate = new Promise((resolve) => { + releaseCheck = resolve + }) + let accessCalls = 0 + mockedFsAccess.mockImplementation(async () => { + accessCalls++ + if (accessCalls === 1) { + await gate + } + throw { code: "ENOENT" } + }) + + const first = guardedWrite(blocker, "queued.txt", "first", "create") + const second = guardedWrite(cancelled, "queued.txt", "second", "create") + + // Both links have captured their generation; the first is parked inside its + // absence check with the second still queued behind it on the same path. + await new Promise((resolve) => setTimeout(resolve, 0)) + expect(accessCalls).toBe(1) + + cancelled.abort = true + cancelled.cancellationGeneration++ + cancelled.abort = false + + releaseCheck() + await first + await expect(second).rejects.toThrow( + "Task was cancelled before this write ran -- the queued publish is not performed.", + ) + + // Only the write that was already running published; the cancelled one did not. + expect(mockedSafeWriteText).toHaveBeenCalledTimes(1) + expect(mockedSafeWriteText).toHaveBeenCalledWith(abs("queued.txt"), "first", { failIfExist: true, expectedResolvedPath: abs("queued.txt"), expectedAncestorIdentities: [] }) + }) + + it("re-checks cancellation under the publish lock before writing", async () => { + // The dequeue check passed; the abort landed while the lock was being taken, + // so the guard must refuse before the publish rather than write for a task that + // is already gone. + const task = createMockTask() + mockedWithFileLock.mockImplementation(function (filePath, operation) { + task.abort = true + return operation(path.resolve(filePath)) + }) + mockedFsAccess.mockRejectedValue({ code: "ENOENT" }) + + await expect(guardedWrite(task, "new-file.txt", "hello", "create")).rejects.toThrow( + "Task was cancelled before this write published -- nothing was written.", + ) + + expect(mockedSafeWriteText).not.toHaveBeenCalled() + }) + + it("re-checks cancellation after the awaited preflight, before publication starts", async () => { + // The abort lands while the version token is being computed. The guard has to + // refuse on the way to the publish, not write for a task that is already gone. + mockedComputeVersionToken.mockImplementation(async () => { + task.abort = true + return "v1" + }) + const reg = new ObservationRegistry() + reg.observe(abs("a.txt"), "v1", true) + const task = createMockTask({ observationRegistry: reg }) + + await expect(guardedWrite(task, "a.txt", "content", "update")).rejects.toThrow( + "Task was cancelled before this write published -- nothing was written.", + ) + + expect(mockedSafeWriteText).not.toHaveBeenCalled() + }) + + it("names the caller's path, not the resolved absolute path, in a model-facing rejection", async () => { + // The guard key stays absolute, but the message and the error field go to the + // model, so they must not carry a user-specific absolute path. + mockedFsAccess.mockResolvedValue(undefined) + const task = createMockTask() + + let error: GuardRejectedError | undefined + await guardedWrite(task, "src/thing.ts", "hello", "create").catch((e: unknown) => { + if (e instanceof GuardRejectedError) { + error = e + return + } + throw e + }) + + expect(error?.message).toBe( + "File already exists at src/thing.ts and was not read before this write -- read the file first, then retry.", + ) + expect(error?.path).toBe("src/thing.ts") + expect(mockedSafeWriteText).not.toHaveBeenCalled() + }) + it("names the caller's path on a stale-version rejection as well", async () => { + // The stale branch is the most common rejection, so it has to follow the same rule + // as the create, delete and cancellation branches. + mockedFsAccess.mockResolvedValue(undefined) + mockedComputeVersionToken.mockResolvedValue("v2") + const reg = new ObservationRegistry() + reg.observe(abs("src/thing.ts"), "v1", true) + const task = createMockTask({ observationRegistry: reg }) + + let staleError: GuardRejectedError | undefined + await guardedWrite(task, "src/thing.ts", "hello", "update").catch((e: unknown) => { + if (e instanceof GuardRejectedError) { + staleError = e + return + } + throw e + }) + + expect(staleError?.message).toBe( + "Stale version -- the file changed since you read it (expected v1, current v2); re-read the file, then retry.", + ) + expect(staleError?.path).toBe("src/thing.ts") + expect(mockedSafeWriteText).not.toHaveBeenCalled() + }) +}) diff --git a/src/core/tools/__tests__/readFileTool.spec.ts b/src/core/tools/__tests__/readFileTool.spec.ts index 6c9e177d38..1eef40f4ad 100644 --- a/src/core/tools/__tests__/readFileTool.spec.ts +++ b/src/core/tools/__tests__/readFileTool.spec.ts @@ -13,10 +13,16 @@ */ import path from "path" +import type { Stats } from "fs" + +import type { LegacyReadFileParams } from "@roo-code/types" import { isBinaryFile } from "isbinaryfile" import { readFileTool, ReadFileTool } from "../ReadFileTool" +import type { Task } from "../../task/Task" +import { ObservationRegistry } from "../../task/observationRegistry" +import { computeVersionToken } from "../../../utils/versionToken" import { formatResponse } from "../../prompts/responses" import { validateImageForProcessing, @@ -136,6 +142,7 @@ interface MockTaskOptions { rooIgnoreAllowed?: boolean maxImageFileSize?: number maxTotalImageSize?: number + observationRegistry?: ObservationRegistry } function createMockTask(options: MockTaskOptions = {}) { @@ -143,6 +150,9 @@ function createMockTask(options: MockTaskOptions = {}) { return { cwd: "/test/workspace", + // Mirror Task: every task always owns an observation registry (A2, #1375). + // Tests asserting on observations pass their own instance via options. + observationRegistry: options.observationRegistry ?? new ObservationRegistry(), api: { getModel: vi.fn().mockReturnValue({ info: { supportsImages }, @@ -187,7 +197,18 @@ describe("ReadFileTool", () => { vi.clearAllMocks() // Default mock implementations - mockedFsStat.mockResolvedValue({ isDirectory: () => false } as any) + // The stat default carries BigIntStats fields (A2, epic #1375): reads now + // token-ize the pre/post stats, so the default must look like a real bigint stat. + // Tests overriding it do so per-call with mockResolvedValue(Once). + mockedFsStat.mockResolvedValue({ + isDirectory: () => false, + dev: BigInt(1), + ino: BigInt(2), + size: BigInt(300), + mtimeNs: BigInt(4_000_000_000n), + ctimeNs: BigInt(5_000_000_000n), + // Cast: the mock only implements the members the tool and versionToken read. + } as unknown as Stats) mockedIsBinaryFile.mockResolvedValue(false) mockedFsReadFile.mockResolvedValue(Buffer.from("test content")) mockedReadWithSlice.mockReturnValue({ @@ -839,7 +860,7 @@ describe("ReadFileTool", () => { mockTask.ask.mockResolvedValue({ response: "yesButtonClicked", text: undefined, images: undefined }) // fs.readFile with "utf8" encoding returns a string, not a Buffer - mockedFsReadFile.mockResolvedValue("line1\nline2\nline3\nline4\nline5" as any) + mockedFsReadFile.mockResolvedValue(Buffer.from("line1\nline2\nline3\nline4\nline5")) await readFileTool.execute( { files: [{ path: "test.ts", lineRanges: [{ start: 2, end: 4 }] }] } as any, @@ -1489,5 +1510,803 @@ describe("ReadFileTool", () => { expect(mockTask.didToolFailInCurrentTurn).toBe(true) }) + + describe("observation registry", () => { + it("records an observation on successful read of an existing file", async () => { + const mockTask = createMockTask({ + observationRegistry: new ObservationRegistry(), + }) + const callbacks = createMockCallbacks() + + // Override the beforeEach default stat mock with proper BigIntStats. + mockedFsStat.mockResolvedValue({ + isDirectory: () => false, + dev: BigInt(1), + ino: BigInt(2), + size: BigInt(300), + mtimeNs: BigInt(4_000_000_000n), + ctimeNs: BigInt(5_000_000_000n), + // Cast: the mock only implements the members the tool and versionToken read. + } as unknown as Stats) + mockedIsBinaryFile.mockResolvedValue(false) + + // Spy on observe to capture the exact key used (Windows path.resolve may use backslashes). + const reg = mockTask.observationRegistry! + const observeSpy = vi.spyOn(reg, "observe") + + // Cast: the mock task only implements the members ReadFileTool.execute touches. + await readFileTool.execute({ path: "existing.ts" }, mockTask as unknown as Task, callbacks) + + // Verify the tool called observe exactly once with a valid token. + expect(observeSpy).toHaveBeenCalledTimes(1) + const [calledPath, calledVersion] = observeSpy.mock.calls[0] + expect(calledPath).toContain("existing.ts") + expect(calledVersion).toMatch(/^\d+:\d+:\d+:\d+:\d+$/) + + // Verify get() returns the same data using the spy-captured key. + const obs = reg.get(calledPath) + expect(obs).toBeDefined() + expect(obs!.version).toBe(calledVersion) + }) + + it("a failed read (absent path) leaves the registry size 0 and does not throw", async () => { + const mockTask = createMockTask({ + observationRegistry: new ObservationRegistry(), + }) + const callbacks = createMockCallbacks() + + mockedFsReadFile.mockRejectedValue(new Error("ENOENT")) + + // Cast: the mock task only implements the members ReadFileTool.execute touches. + await readFileTool.execute({ path: "missing.ts" }, mockTask as unknown as Task, callbacks) + + // observationRegistry is guaranteed present because we passed it in createMockTask. + const reg = mockTask.observationRegistry + expect(reg).toBeDefined() + expect(reg!.size).toBe(0) + }) + + it("records an observation for legacy-format reads of existing files", async () => { + const mockTask = createMockTask({ + observationRegistry: new ObservationRegistry(), + }) + const callbacks = createMockCallbacks() + + mockedFsStat.mockResolvedValue({ + isDirectory: () => false, + dev: BigInt(1), + ino: BigInt(2), + size: BigInt(300), + mtimeNs: BigInt(4_000_000_000n), + ctimeNs: BigInt(5_000_000_000n), + // Cast: the mock only implements the members the tool and versionToken read. + } as unknown as Stats) + mockedIsBinaryFile.mockResolvedValue(false) + + const reg = mockTask.observationRegistry! + const observeSpy = vi.spyOn(reg, "observe") + + // Typed legacy (pre-refactor) params: the multi-file format with the + // _legacyFormat discriminant (see LegacyReadFileParams). + const legacyParams: LegacyReadFileParams = { + files: [{ path: "legacy.ts" }], + _legacyFormat: true, + } + + // Cast: the mock task only implements the members ReadFileTool.execute touches. + await readFileTool.execute(legacyParams, mockTask as unknown as Task, callbacks) + + expect(observeSpy).toHaveBeenCalledTimes(1) + const [calledPath, calledVersion] = observeSpy.mock.calls[0] + expect(calledPath).toContain("legacy.ts") + expect(calledVersion).toMatch(/^\d+:\d+:\d+:\d+:\d+$/) + }) + + it("does not observe when the file mutates between the pre-read and post-read stats", async () => { + const mockTask = createMockTask({ + observationRegistry: new ObservationRegistry(), + }) + const callbacks = createMockCallbacks() + + const preStats = { + isDirectory: () => false, + dev: BigInt(1), + ino: BigInt(2), + size: BigInt(300), + mtimeNs: BigInt(4_000_000_000n), + ctimeNs: BigInt(5_000_000_000n), + } + // A mutation lands mid-read: the post-read stat differs. + const postStats = { ...preStats, size: BigInt(301) } + + // Call order: directory check, pre-read stat, post-read stat. + mockedFsStat + .mockResolvedValueOnce({ isDirectory: () => false } as unknown as Stats) + .mockResolvedValueOnce(preStats as unknown as Stats) + .mockResolvedValueOnce(postStats as unknown as Stats) + mockedIsBinaryFile.mockResolvedValue(false) + + const reg = mockTask.observationRegistry! + const observeSpy = vi.spyOn(reg, "observe") + + // Cast: the mock task only implements the members ReadFileTool.execute touches. + await readFileTool.execute({ path: "mutated.ts" }, mockTask as unknown as Task, callbacks) + + // The read itself succeeded, but the target stays unobserved: the content the + // model received is not the on-disk state, so observing it would let a later + // write match a token the model never saw. + expect(observeSpy).not.toHaveBeenCalled() + expect(reg.size).toBe(0) + expect(mockTask.didToolFailInCurrentTurn).toBe(false) + }) + + it("leaves the target unobserved without failing the read when the pre-read stat fails", async () => { + const mockTask = createMockTask({ + observationRegistry: new ObservationRegistry(), + }) + const callbacks = createMockCallbacks() + + // Directory check OK; the pre-read stat fails (caught, target unobserved). + mockedFsStat + .mockResolvedValueOnce({ isDirectory: () => false } as unknown as Stats) + .mockRejectedValueOnce(new Error("EACCES")) + mockedIsBinaryFile.mockResolvedValue(false) + + const reg = mockTask.observationRegistry! + const observeSpy = vi.spyOn(reg, "observe") + + // Cast: the mock task only implements the members ReadFileTool.execute touches. + await readFileTool.execute({ path: "stat-fail.ts" }, mockTask as unknown as Task, callbacks) + + expect(observeSpy).not.toHaveBeenCalled() + expect(reg.size).toBe(0) + // The read still succeeds — a stat failure never fails the read. + expect(mockTask.didToolFailInCurrentTurn).toBe(false) + // Assert the pushed payload, not just that something was pushed. + const pushed = callbacks.pushToolResult.mock.calls[0][0] + expect(pushed).toContain("File: stat-fail.ts") + expect(pushed).toContain("test content") + expect(pushed).not.toContain("Error:") + }) + + it("leaves the target unobserved without failing the read when the post-read stat fails", async () => { + const mockTask = createMockTask({ + observationRegistry: new ObservationRegistry(), + }) + const callbacks = createMockCallbacks() + + const okStats = { + isDirectory: () => false, + dev: BigInt(1), + ino: BigInt(2), + size: BigInt(300), + mtimeNs: BigInt(4_000_000_000n), + ctimeNs: BigInt(5_000_000_000n), + } + // Directory check and pre-read stat OK; the post-read stat fails. + mockedFsStat + .mockResolvedValueOnce({ isDirectory: () => false } as unknown as Stats) + .mockResolvedValueOnce(okStats as unknown as Stats) + .mockRejectedValueOnce(new Error("EACCES")) + mockedIsBinaryFile.mockResolvedValue(false) + + const reg = mockTask.observationRegistry! + const observeSpy = vi.spyOn(reg, "observe") + + // Cast: the mock task only implements the members ReadFileTool.execute touches. + await readFileTool.execute({ path: "post-stat-fail.ts" }, mockTask as unknown as Task, callbacks) + + expect(observeSpy).not.toHaveBeenCalled() + expect(reg.size).toBe(0) + expect(mockTask.didToolFailInCurrentTurn).toBe(false) + // Assert the pushed payload, not just that something was pushed. + const pushed = callbacks.pushToolResult.mock.calls[0][0] + expect(pushed).toContain("File: post-stat-fail.ts") + expect(pushed).toContain("test content") + expect(pushed).not.toContain("Error:") + }) + + it("legacy format: does not observe when the file mutates between the pre-read and post-read stats", async () => { + const mockTask = createMockTask({ + observationRegistry: new ObservationRegistry(), + }) + const callbacks = createMockCallbacks() + + const preStats = { + isDirectory: () => false, + dev: BigInt(1), + ino: BigInt(2), + size: BigInt(300), + mtimeNs: BigInt(4_000_000_000n), + ctimeNs: BigInt(5_000_000_000n), + } + // Call order: directory check, pre-read stat, post-read stat (mutated). + mockedFsStat + .mockResolvedValueOnce({ isDirectory: () => false } as unknown as Stats) + .mockResolvedValueOnce(preStats as unknown as Stats) + .mockResolvedValueOnce({ ...preStats, size: BigInt(301) } as unknown as Stats) + mockedIsBinaryFile.mockResolvedValue(false) + + const reg = mockTask.observationRegistry! + const observeSpy = vi.spyOn(reg, "observe") + + const legacyParams: LegacyReadFileParams = { + files: [{ path: "legacy-mutated.ts" }], + _legacyFormat: true, + } + + // Cast: the mock task only implements the members ReadFileTool.execute touches. + await readFileTool.execute(legacyParams, mockTask as unknown as Task, callbacks) + + expect(observeSpy).not.toHaveBeenCalled() + expect(reg.size).toBe(0) + expect(mockTask.didToolFailInCurrentTurn).toBe(false) + }) + + it("legacy format: leaves the target unobserved when a stat fails without failing the read", async () => { + const mockTask = createMockTask({ + observationRegistry: new ObservationRegistry(), + }) + const callbacks = createMockCallbacks() + + // Directory check OK; the pre-read stat fails (caught, target unobserved). + mockedFsStat + .mockResolvedValueOnce({ isDirectory: () => false } as unknown as Stats) + .mockRejectedValueOnce(new Error("EACCES")) + mockedIsBinaryFile.mockResolvedValue(false) + + const reg = mockTask.observationRegistry! + const observeSpy = vi.spyOn(reg, "observe") + + const legacyParams: LegacyReadFileParams = { + files: [{ path: "legacy-stat-fail.ts" }], + _legacyFormat: true, + } + + // Cast: the mock task only implements the members ReadFileTool.execute touches. + await readFileTool.execute(legacyParams, mockTask as unknown as Task, callbacks) + + expect(observeSpy).not.toHaveBeenCalled() + expect(reg.size).toBe(0) + expect(mockTask.didToolFailInCurrentTurn).toBe(false) + // Assert the pushed payload, not just that something was pushed. + const pushed = callbacks.pushToolResult.mock.calls[0][0] + expect(pushed).toContain("File: legacy-stat-fail.ts") + expect(pushed).toContain("test content") + expect(pushed).not.toContain("Error:") + }) + it("legacy format: leaves the target unobserved when the post-read stat fails", async () => { + const mockTask = createMockTask({ + observationRegistry: new ObservationRegistry(), + }) + const callbacks = createMockCallbacks() + + const okStats = { + isDirectory: () => false, + dev: BigInt(1), + ino: BigInt(2), + size: BigInt(300), + mtimeNs: BigInt(4_000_000_000n), + ctimeNs: BigInt(5_000_000_000n), + } + // Directory check and pre-read stat OK; the post-read stat fails. + mockedFsStat + .mockResolvedValueOnce({ isDirectory: () => false } as unknown as Stats) + .mockResolvedValueOnce(okStats as unknown as Stats) + .mockRejectedValueOnce(new Error("EACCES")) + mockedIsBinaryFile.mockResolvedValue(false) + + const reg = mockTask.observationRegistry! + const observeSpy = vi.spyOn(reg, "observe") + + const legacyParams: LegacyReadFileParams = { + files: [{ path: "legacy-post-stat-fail.ts" }], + _legacyFormat: true, + } + + // Cast: the mock task only implements the members ReadFileTool.execute touches. + await readFileTool.execute(legacyParams, mockTask as unknown as Task, callbacks) + + expect(observeSpy).not.toHaveBeenCalled() + expect(reg.size).toBe(0) + expect(mockTask.didToolFailInCurrentTurn).toBe(false) + // Assert the pushed payload, not just that something was pushed. + const pushed = callbacks.pushToolResult.mock.calls[0][0] + expect(pushed).toContain("File: legacy-post-stat-fail.ts") + expect(pushed).toContain("test content") + expect(pushed).not.toContain("Error:") + }) + it("two separate Task-owned registries are independent", async () => { + const regA = new ObservationRegistry() + const regB = new ObservationRegistry() + regA.observe("/shared.ts", "v1") + expect(regA.get("/shared.ts")!.version).toBe("v1") + expect(regB.get("/shared.ts")).toBeUndefined() + regB.observe("/shared.ts", "v2") + expect(regA.get("/shared.ts")!.version).toBe("v1") + expect(regB.get("/shared.ts")!.version).toBe("v2") + }) + }) + + describe("read completeness scope (S4b follow-up #46)", () => { + // The stat mock only implements the members the tool and versionToken read. + const bigintStats = (): Stats => + ({ + isDirectory: () => false, + dev: BigInt(1), + ino: BigInt(2), + size: BigInt(300), + mtimeNs: BigInt(4_000_000_000n), + ctimeNs: BigInt(5_000_000_000n), + }) as unknown as Stats + + it("native: a full, untruncated slice read from line 1 records a complete observation", async () => { + const mockTask = createMockTask({ + observationRegistry: new ObservationRegistry(), + }) + const callbacks = createMockCallbacks() + + mockedFsStat.mockResolvedValue(bigintStats()) + mockedIsBinaryFile.mockResolvedValue(false) + mockedFsReadFile.mockResolvedValue(Buffer.from("a\nb\n")) + mockedReadWithSlice.mockReturnValue({ + content: "1 | a\n2 | b", + returnedLines: 2, + totalLines: 2, + wasTruncated: false, + includedRanges: [[1, 2]], + }) + + const reg = mockTask.observationRegistry! + const observeSpy = vi.spyOn(reg, "observe") + + await readFileTool.execute({ path: "full.ts" }, mockTask as unknown as Task, callbacks) + + expect(observeSpy).toHaveBeenCalledTimes(1) + const [calledPath, calledVersion, calledComplete] = observeSpy.mock.calls[0] + expect(calledPath).toContain("full.ts") + expect(calledVersion).toMatch(/^\d+:\d+:\d+:\d+:\d+$/) + expect(calledComplete).toBe(true) + expect(reg.get(calledPath)!.complete).toBe(true) + }) + + it("native: a truncated slice read records a partial observation", async () => { + const mockTask = createMockTask({ + observationRegistry: new ObservationRegistry(), + }) + const callbacks = createMockCallbacks() + + mockedFsStat.mockResolvedValue(bigintStats()) + mockedIsBinaryFile.mockResolvedValue(false) + mockedFsReadFile.mockResolvedValue(Buffer.from("a\nb\nc\nd\ne")) + mockedReadWithSlice.mockReturnValue({ + content: "1 | a", + returnedLines: 1, + totalLines: 5, + wasTruncated: true, + includedRanges: [[1, 1]], + }) + + const reg = mockTask.observationRegistry! + const observeSpy = vi.spyOn(reg, "observe") + + await readFileTool.execute( + { path: "trunc.ts", offset: 1, limit: 1 }, + mockTask as unknown as Task, + callbacks, + ) + + expect(observeSpy).toHaveBeenCalledTimes(1) + const [calledPath, , calledComplete] = observeSpy.mock.calls[0] + expect(calledComplete).toBe(false) + expect(reg.get(calledPath)!.complete).toBe(false) + }) + + it("native: a full read whose line content was clipped records a partial observation", async () => { + const mockTask = createMockTask({ + observationRegistry: new ObservationRegistry(), + }) + const callbacks = createMockCallbacks() + + mockedFsStat.mockResolvedValue(bigintStats()) + mockedIsBinaryFile.mockResolvedValue(false) + mockedFsReadFile.mockResolvedValue(Buffer.from("a\nb\n")) + mockedReadWithSlice.mockReturnValue({ + content: "1 | a\n2 | b", + returnedLines: 2, + totalLines: 2, + wasTruncated: false, + hasClippedLines: true, + includedRanges: [[1, 2]], + }) + + const reg = mockTask.observationRegistry! + const observeSpy = vi.spyOn(reg, "observe") + + await readFileTool.execute({ path: "clipped.ts" }, mockTask as unknown as Task, callbacks) + + const [, , calledComplete] = observeSpy.mock.calls[0] + expect(calledComplete).toBe(false) + // Every line was returned, so the notice must not point at a next + // offset that is beyond the file. + const pushed = callbacks.pushToolResult.mock.calls[0][0] + expect(pushed).toContain("clipped in this view") + expect(pushed).not.toContain("To read more") + // The notice is added on top of the read, it does not replace it. + expect(pushed).toContain("1 | a") + }) + it("native: a clipped slice that starts past line 1 does not claim the file was read in full", async () => { + const mockTask = createMockTask({ + observationRegistry: new ObservationRegistry(), + }) + const callbacks = createMockCallbacks() + + mockedFsStat.mockResolvedValue(bigintStats()) + mockedIsBinaryFile.mockResolvedValue(false) + mockedFsReadFile.mockResolvedValue(Buffer.from("a\nb\n")) + mockedReadWithSlice.mockReturnValue({ + content: "2 | b", + returnedLines: 1, + totalLines: 2, + wasTruncated: false, + hasClippedLines: true, + includedRanges: [[2, 2]], + }) + + const reg = mockTask.observationRegistry! + const observeSpy = vi.spyOn(reg, "observe") + + await readFileTool.execute({ path: "clipped.ts", offset: 2 }, mockTask as unknown as Task, callbacks) + + const [, , calledComplete] = observeSpy.mock.calls[0] + expect(calledComplete).toBe(false) + + const pushed = callbacks.pushToolResult.mock.calls[0][0] + expect(pushed).toContain("clipped in this view") + // The notice has to agree with the recorded completeness: the view + // started past line 1, so it cannot claim a full read. + expect(pushed).not.toContain("The file was read in full") + expect(pushed).toContain("The view starts at line 2, so lines 1-1 were not shown") + // The content must not inherit the source indentation: the template literal's + // leading tabs would reach the model as part of the first line of the view. + // This branch uses the same single tab as the truncated branch above. + expect(pushed).toContain("\n\t2 | b") + expect(pushed).not.toContain("\n\t\t2 | b") + }) + + + it("native: a truncated slice that also clipped a line reports both notices", async () => { + // A long line inside a slice that also cut lines off is a plausible case, + // and the response has to say both things. + const mockTask = createMockTask({ + observationRegistry: new ObservationRegistry(), + }) + const callbacks = createMockCallbacks() + + mockedFsStat.mockResolvedValue(bigintStats()) + mockedIsBinaryFile.mockResolvedValue(false) + mockedFsReadFile.mockResolvedValue(Buffer.from("a\nb\nc")) + mockedReadWithSlice.mockReturnValue({ + content: "1 | a\n2 | b", + returnedLines: 2, + totalLines: 3, + wasTruncated: true, + hasClippedLines: true, + includedRanges: [[1, 2]], + }) + + const reg = mockTask.observationRegistry! + const observeSpy = vi.spyOn(reg, "observe") + + await readFileTool.execute({ path: "both.ts" }, mockTask as unknown as Task, callbacks) + + const [, , calledComplete] = observeSpy.mock.calls[0] + expect(calledComplete).toBe(false) + + const pushed = callbacks.pushToolResult.mock.calls[0][0] + expect(pushed).toContain("Showing lines 1-2 of 3 total lines") + expect(pushed).toContain("clipped in this view") + }) + + it("native: an offset read that is not truncated still records a partial observation", async () => { + const mockTask = createMockTask({ + observationRegistry: new ObservationRegistry(), + }) + const callbacks = createMockCallbacks() + + mockedFsStat.mockResolvedValue(bigintStats()) + mockedIsBinaryFile.mockResolvedValue(false) + mockedFsReadFile.mockResolvedValue(Buffer.from("a\nb\nc\nd\ne")) + mockedReadWithSlice.mockReturnValue({ + content: "4 | d\n5 | e", + returnedLines: 2, + totalLines: 5, + wasTruncated: false, + includedRanges: [[4, 5]], + }) + + const reg = mockTask.observationRegistry! + const observeSpy = vi.spyOn(reg, "observe") + + await readFileTool.execute( + { path: "offset.ts", offset: 4, limit: 2 }, + mockTask as unknown as Task, + callbacks, + ) + + expect(observeSpy).toHaveBeenCalledTimes(1) + const [calledPath, , calledComplete] = observeSpy.mock.calls[0] + expect(calledComplete).toBe(false) + }) + + it("native: an indentation-mode block read records a partial observation", async () => { + const mockTask = createMockTask({ + observationRegistry: new ObservationRegistry(), + }) + const callbacks = createMockCallbacks() + + mockedFsStat.mockResolvedValue(bigintStats()) + mockedIsBinaryFile.mockResolvedValue(false) + mockedFsReadFile.mockResolvedValue(Buffer.from("function f() { return 1 }")) + mockedReadWithIndentation.mockReturnValue({ + content: "10 | function f() {", + wasTruncated: false, + includedRanges: [[10, 20]], + totalLines: 100, + returnedLines: 11, + }) + + const reg = mockTask.observationRegistry! + const observeSpy = vi.spyOn(reg, "observe") + + await readFileTool.execute( + { path: "indent.ts", mode: "indentation" }, + mockTask as unknown as Task, + callbacks, + ) + + expect(observeSpy).toHaveBeenCalledTimes(1) + const [calledPath, , calledComplete] = observeSpy.mock.calls[0] + expect(calledComplete).toBe(false) + }) + + it("legacy: a line-range read records a partial observation", async () => { + const mockTask = createMockTask({ + observationRegistry: new ObservationRegistry(), + }) + const callbacks = createMockCallbacks() + + mockedFsStat.mockResolvedValue(bigintStats()) + mockedIsBinaryFile.mockResolvedValue(false) + mockedFsReadFile.mockResolvedValue(Buffer.from("a\nb\nc\nd\ne")) + + const reg = mockTask.observationRegistry! + const observeSpy = vi.spyOn(reg, "observe") + + const legacyParams: LegacyReadFileParams = { + files: [{ path: "ranges.ts", lineRanges: [{ start: 2, end: 4 }] }], + _legacyFormat: true, + } + + await readFileTool.execute(legacyParams, mockTask as unknown as Task, callbacks) + + expect(observeSpy).toHaveBeenCalledTimes(1) + const [calledPath, , calledComplete] = observeSpy.mock.calls[0] + expect(calledPath).toContain("ranges.ts") + expect(calledComplete).toBe(false) + }) + + it("legacy: a full, untruncated slice read records a complete observation", async () => { + const mockTask = createMockTask({ + observationRegistry: new ObservationRegistry(), + }) + const callbacks = createMockCallbacks() + + mockedFsStat.mockResolvedValue(bigintStats()) + mockedIsBinaryFile.mockResolvedValue(false) + mockedFsReadFile.mockResolvedValue(Buffer.from("a\nb")) + mockedReadWithSlice.mockReturnValue({ + content: "1 | a\n2 | b", + returnedLines: 2, + totalLines: 2, + wasTruncated: false, + includedRanges: [[1, 2]], + }) + + const reg = mockTask.observationRegistry! + const observeSpy = vi.spyOn(reg, "observe") + + const legacyParams: LegacyReadFileParams = { + files: [{ path: "legacy-full.ts" }], + _legacyFormat: true, + } + + await readFileTool.execute(legacyParams, mockTask as unknown as Task, callbacks) + + expect(observeSpy).toHaveBeenCalledTimes(1) + const [calledPath, , calledComplete] = observeSpy.mock.calls[0] + expect(calledComplete).toBe(true) + + // Nothing was omitted and nothing was clipped, so no note is added. + const pushed = callbacks.pushToolResult.mock.calls[0][0] + expect(pushed).not.toContain("clipped in this view") + expect(pushed).not.toContain("total lines") + }) + + it("legacy: a full read with a clipped line records a partial observation and reports the clipping", async () => { + const mockTask = createMockTask({ + observationRegistry: new ObservationRegistry(), + }) + const callbacks = createMockCallbacks() + + mockedFsStat.mockResolvedValue(bigintStats()) + mockedIsBinaryFile.mockResolvedValue(false) + mockedFsReadFile.mockResolvedValue(Buffer.from("a\nb")) + mockedReadWithSlice.mockReturnValue({ + content: "1 | a\n2 | b", + returnedLines: 2, + totalLines: 2, + wasTruncated: false, + hasClippedLines: true, + includedRanges: [[1, 2]], + }) + + const reg = mockTask.observationRegistry! + const observeSpy = vi.spyOn(reg, "observe") + + const legacyParams: LegacyReadFileParams = { + files: [{ path: "legacy-clipped.ts" }], + _legacyFormat: true, + } + + await readFileTool.execute(legacyParams, mockTask as unknown as Task, callbacks) + + const [, , calledComplete] = observeSpy.mock.calls[0] + expect(calledComplete).toBe(false) + + // Every line was returned, so the note reports the clipping instead of + // a showing-N-of-N count that would point past the file. + const pushed = callbacks.pushToolResult.mock.calls[0][0] + expect(pushed).toContain("clipped in this view") + expect(pushed).not.toContain("showing 2 of 2 total lines") + }) + + it("legacy: a truncated slice that also clipped a line reports both notices", async () => { + const mockTask = createMockTask({ + observationRegistry: new ObservationRegistry(), + }) + const callbacks = createMockCallbacks() + + mockedFsStat.mockResolvedValue(bigintStats()) + mockedIsBinaryFile.mockResolvedValue(false) + mockedFsReadFile.mockResolvedValue(Buffer.from("a\nb\nc")) + mockedReadWithSlice.mockReturnValue({ + content: "1 | a\n2 | b", + returnedLines: 2, + totalLines: 3, + wasTruncated: true, + hasClippedLines: true, + includedRanges: [[1, 2]], + }) + + const reg = mockTask.observationRegistry! + const observeSpy = vi.spyOn(reg, "observe") + + const legacyParams: LegacyReadFileParams = { + files: [{ path: "legacy-both.ts" }], + _legacyFormat: true, + } + + await readFileTool.execute(legacyParams, mockTask as unknown as Task, callbacks) + + const [, , calledComplete] = observeSpy.mock.calls[0] + expect(calledComplete).toBe(false) + + const pushed = callbacks.pushToolResult.mock.calls[0][0] + expect(pushed).toContain("showing 2 of 3 total lines") + expect(pushed).toContain("clipped in this view") + }) + + it("legacy: a slice truncated to the default limit records a partial observation", async () => { + const mockTask = createMockTask({ + observationRegistry: new ObservationRegistry(), + }) + const callbacks = createMockCallbacks() + + mockedFsStat.mockResolvedValue(bigintStats()) + mockedIsBinaryFile.mockResolvedValue(false) + mockedFsReadFile.mockResolvedValue(Buffer.from("a\nb\nc")) + mockedReadWithSlice.mockReturnValue({ + content: "1 | a", + returnedLines: 1, + totalLines: 5000, + wasTruncated: true, + includedRanges: [[1, 1]], + }) + + const reg = mockTask.observationRegistry! + const observeSpy = vi.spyOn(reg, "observe") + + const legacyParams: LegacyReadFileParams = { + files: [{ path: "legacy-trunc.ts" }], + _legacyFormat: true, + } + + await readFileTool.execute(legacyParams, mockTask as unknown as Task, callbacks) + + expect(observeSpy).toHaveBeenCalledTimes(1) + const [calledPath, , calledComplete] = observeSpy.mock.calls[0] + expect(calledComplete).toBe(false) + + // Lines were omitted here, so the note reports the omitted range rather + // than clipping. + const pushed = callbacks.pushToolResult.mock.calls[0][0] + expect(pushed).toContain("showing 1 of 5000 total lines") + }) + + it("native: a read whose bytes did not survive the UTF-8 decode records a partial observation", async () => { + const mockTask = createMockTask({ + observationRegistry: new ObservationRegistry(), + }) + const callbacks = createMockCallbacks() + + // 0xFF is not valid UTF-8, so the model receives U+FFFD instead of the byte. + const raw = Buffer.from([0x61, 0xff]) + mockedFsStat.mockResolvedValue(bigintStats()) + mockedIsBinaryFile.mockResolvedValue(false) + mockedFsReadFile.mockResolvedValue(raw) + mockedReadWithSlice.mockReturnValue({ + content: "1 | a\uFFFD", + returnedLines: 1, + totalLines: 1, + wasTruncated: false, + includedRanges: [[1, 1]], + }) + + const reg = mockTask.observationRegistry! + const observeSpy = vi.spyOn(reg, "observe") + + await readFileTool.execute({ path: "lossy.ts" }, mockTask as unknown as Task, callbacks) + + expect(observeSpy).toHaveBeenCalledTimes(1) + const [calledPath, , calledComplete] = observeSpy.mock.calls[0] + expect(calledComplete).toBe(false) + expect(reg.get(calledPath)!.complete).toBe(false) + }) + + it("legacy: a read whose bytes did not survive the UTF-8 decode records a partial observation", async () => { + const mockTask = createMockTask({ + observationRegistry: new ObservationRegistry(), + }) + const callbacks = createMockCallbacks() + + const raw = Buffer.from([0x61, 0xff]) + mockedFsStat.mockResolvedValue(bigintStats()) + mockedIsBinaryFile.mockResolvedValue(false) + mockedFsReadFile.mockResolvedValue(raw) + mockedReadWithSlice.mockReturnValue({ + content: "1 | a\uFFFD", + returnedLines: 1, + totalLines: 1, + wasTruncated: false, + includedRanges: [[1, 1]], + }) + + const reg = mockTask.observationRegistry! + const observeSpy = vi.spyOn(reg, "observe") + + const legacyParams: LegacyReadFileParams = { + files: [{ path: "legacy-lossy.ts" }], + _legacyFormat: true, + } + + await readFileTool.execute(legacyParams, mockTask as unknown as Task, callbacks) + + expect(observeSpy).toHaveBeenCalledTimes(1) + const [calledPath, , calledComplete] = observeSpy.mock.calls[0] + expect(calledComplete).toBe(false) + expect(reg.get(calledPath)!.complete).toBe(false) + }) + }) }) }) diff --git a/src/core/tools/guardedWrite.ts b/src/core/tools/guardedWrite.ts new file mode 100644 index 0000000000..2f876e115b --- /dev/null +++ b/src/core/tools/guardedWrite.ts @@ -0,0 +1,656 @@ +/** + * Guarded-write compare-and-swap core (upstream epic #1375, phase A4a). + * + * Wraps the S3 safeWriteText publish primitive behind version-token guards so + * that every write is deterministic: + * + * - an unobserved target may only be created when it is absent + * (createIfAbsent); + * - an observed target is published only when the on-disk version token still + * matches the current observation token (replaceIfVersion); + * - an edit-style write requires a prior observation (unobservedEditGuard). + * + * A per-absolute-path FIFO chain of tail promises orders concurrent + * in-process writes to the same path. Each publish refreshes the observation to + * the token it wrote when the new token can be computed, so same-task writes + * apply last-write-wins; when that refresh fails the observation keeps the + * previous observation token. A write that goes through replaceIfVersion fails + * stale when the on-disk token differs from the token the observation currently + * holds; an observed "create" whose target has disappeared instead uses + * createIfAbsent and can recreate it. Observations come from the task's S2 + * ObservationRegistry and authorize the write as well as the version check. + */ + +import * as fs from "fs/promises" +import * as path from "path" + +import { safeWriteText, TargetExistsError, type DirectoryIdentity } from "../../services/file-safety/safeWriteText" +import { computeVersionToken } from "../../utils/versionToken" +import { withFileLock } from "../../utils/fileLock" +import { resolveLockKey } from "../../services/file-safety/safeWriteText" +import type { Task } from "../task/Task" + +// -- Types ------------------------------------------------------------------ + +/** Write kind that drives guard selection. */ +export type GuardedWriteKind = "create" | "update" | "edit" + +/** Error thrown when a guard rejects a write. Exported so a caller can tell a guard verdict from an unrelated failure. + */ +export class GuardRejectedError extends Error { + constructor( + message: string, + readonly path: string, + ) { + super(message) + this.name = "GuardRejectedError" + } +} + +// -- Per-path tail-promise chain -------------------------------------------- + +/** + * Per-absolute-path FIFO chain of pending guarded writes (tail promise per + * path). Every write enqueues onto the current tail for its path, so + * concurrent writes to the same path run one at a time in submission order. + * + * The chain never leaks a rejection through itself: each link settles, a + * rejected link is skipped by the next writer (a failed write must not block + * later writes to the same path), and every caller receives its own link + * promise to handle. + * + * Settled entries are evicted (below), so a long-lived extension does not + * accumulate a map entry per distinct written path. + */ +const pendingChains = new Map>() + +/** + * Enqueue a write operation on the per-path FIFO chain. + * + * Returns the promise for this link; it always settles. A prior link that + * rejected is skipped, not propagated. The map entry for this link is + * deleted once it settles — but only while it is still the current tail for + * the path, so a replacement enqueued in the meantime keeps ownership. + */ +function enqueue(pathKey: string, fn: () => Promise): Promise { + const prev = pendingChains.get(pathKey) ?? Promise.resolve() + const next = prev.then(fn, fn) + pendingChains.set(pathKey, next) + void next.then( + () => { + if (pendingChains.get(pathKey) === next) { + pendingChains.delete(pathKey) + } + }, + () => { + if (pendingChains.get(pathKey) === next) { + pendingChains.delete(pathKey) + } + }, + ) + return next +} + +// -- Guard primitives -------------------------------------------------------- + +/** + * Extract a Node errno code (e.g. "ENOENT") from a thrown value, or + * undefined when the value carries none. + */ +export function errorCode(error: unknown): string | undefined { + return typeof error === "object" && error !== null && "code" in error + ? (error as { code?: string }).code + : undefined +} + +/** + * Cancellation re-check under the publish lock. A write queued on the FIFO + * chain can outlive its task: the caller already reported the write to the model, + * so a task aborted while its link waited must not publish afterwards. + */ +function cancelledBeforePublish(absolutePath: string, displayPath: string, isCancelled?: () => boolean): void { + if (isCancelled?.()) { + throw new GuardRejectedError( + "Task was cancelled before this write published -- nothing was written.", + displayPath, + ) + } +} + +/** True when the path is absent on disk (fs.access reports ENOENT). */ +async function fileIsAbsent(absolutePath: string): Promise { + try { + await fs.access(absolutePath) + return false + } catch (error: unknown) { + return errorCode(error) === "ENOENT" + } +} + +/** + * Publish content only if the target file does not exist. + * + * Rejects with a loud remediation error when the file already exists: the + * write was issued for a file that was never read, so the caller must read + * the file first, then retry. + */ +/** + * Read the on-disk token after a publish, best-effort: a publish that + * succeeded is not undone by a failed stat, so the caller keeps the publish + * and only skips the observation refresh. + */ +async function tokenAfterPublish(absolutePath: string): Promise { + return computeVersionToken(absolutePath).catch(() => undefined) +} + +export async function createIfAbsent( + absolutePath: string, + content: string | Uint8Array, + displayPath: string, + // Re-checked under the lock: a link that waited on the FIFO chain can outlive + // the task that queued it. + isCancelled?: () => boolean, + // Re-checked under the lock, immediately before the publish: the path was authorized + // when it was queued, but a symlink can be swapped in while the link waited on the + // FIFO chain or on this lock. + // Resolves the path again and returns the authorized target plus the directory + // identities it was authorized against, so the publish can pin both. + verifyTarget?: () => Promise, +): Promise { + // Lock the key every other writer to this file uses: the resolved publish + // target, so a symlink alias and its referent share one lock. + return withFileLock(await resolveLockKey(absolutePath), async () => { + cancelledBeforePublish(absolutePath, displayPath, isCancelled) + try { + await fs.access(absolutePath) + } catch (error: unknown) { + if (errorCode(error) !== "ENOENT") { + // A real I/O failure (EACCES, EIO, ...) -- not a guard verdict. + throw error + } + // Immediately before publication starts. + cancelledBeforePublish(absolutePath, displayPath, isCancelled) + const authorized = await verifyTarget?.() + // No-replace commit. The access check above only proves absence at the moment + // it runs: a writer that never takes the advisory lock can create the target + // before this publish, and a plain rename would silently replace that newer + // file. The commit is therefore a link that fails EEXIST, and the collision is + // reported as the same guard verdict the pre-check produces. + try { + await safeWriteText(absolutePath, content, { + failIfExist: true, + expectedResolvedPath: authorized?.target, + expectedAncestorIdentities: authorized?.ancestors, + }) + } catch (error: unknown) { + if (error instanceof TargetExistsError) { + throw new GuardRejectedError( + "File already exists at " + + displayPath + + " and was not read before this write -- read the file first, then retry.", + displayPath, + ) + } + throw error + } + // Read the new token under the same lock, otherwise a peer lock-using + // writer can publish in the gap and the caller records that writer's + // token as its own observation. + return tokenAfterPublish(absolutePath) + } + + throw new GuardRejectedError( + "File already exists at " + + displayPath + + " and was not read before this write -- read the file first, then retry.", + displayPath, + ) + }) +} + +/** + * Publish content only if the current on-disk version token equals + * expectedVersion (the token observed at read time). + * + * On a match the content is published via the S3 safeWriteText primitive; on + * a mismatch the write is rejected stale with a re-read-then-retry + * remediation suffix. + * + * Atomicity boundary: the check and the publish run inside one acquisition of the + * shared advisory lock, and the post-publish token is read under that same lock, so + * no writer that participates in the protocol can interleave here. Every production + * caller of the publish primitive holds the same canonical key (safeWriteJson + * acquires it before publishing; TaskHistoryStore deletion takes it on the same + * resolved key). The primitive itself cannot re-acquire the lock -- withFileLock must + * not be re-entered inside an operation, and the callers already hold it, so wrapping + * it would deadlock them. A writer that never takes the lock is outside the supported + * threat model: a plain rename has no conditional form, so no advisory mechanism can + * bind a checked version to it. + */ +export async function replaceIfVersion( + absolutePath: string, + expectedVersion: string, + content: string | Uint8Array, + // Re-checked under the lock: a link that waited on the FIFO chain can outlive + // the task that queued it. + displayPath: string, + isCancelled?: () => boolean, + // Re-checked under the lock, immediately before the publish: the path was authorized + // when it was queued, but a symlink can be swapped in while the link waited on the + // FIFO chain or on this lock. + // Resolves the path again and returns the authorized target plus the directory + // identities it was authorized against, so the publish can pin both. + verifyTarget?: () => Promise, +): Promise { + // Lock the key every other writer to this file uses: the resolved publish + // target, so a symlink alias and its referent share one lock. + return withFileLock(await resolveLockKey(absolutePath), async () => { + cancelledBeforePublish(absolutePath, displayPath, isCancelled) + let currentVersion: string + try { + currentVersion = await computeVersionToken(absolutePath) + } catch (error: unknown) { + if (errorCode(error) === "ENOENT") { + // The observed file was deleted after the read: the version recorded + // at read time no longer exists on disk. Normalize the raw ENOENT + // into the guard's re-read-then-retry contract so the caller gets a + // remediation it can act on, not a raw errno. + throw new GuardRejectedError( + "File was deleted after it was read -- the version recorded at read time (" + + expectedVersion + + ") no longer exists; re-read the file, then retry.", + displayPath, + ) + } + // A real I/O failure (EACCES, EIO, ...) -- not a guard verdict. + throw error + } + + // Re-checked after the awaited preflight: the task can be aborted while this + // operation waits, and a publish that starts after that is a write the caller + // has already reported as not performed. + cancelledBeforePublish(absolutePath, displayPath, isCancelled) + + if (currentVersion === expectedVersion) { + // Immediately before publication starts. + cancelledBeforePublish(absolutePath, displayPath, isCancelled) + const authorized = await verifyTarget?.() + await safeWriteText(absolutePath, content, { + expectedResolvedPath: authorized?.target, + expectedAncestorIdentities: authorized?.ancestors, + }) + // Read the new token under the same lock, otherwise a peer lock-using + // writer can publish in the gap and the caller records that writer's + // token as its own observation. + return tokenAfterPublish(absolutePath) + } + + throw new GuardRejectedError( + "Stale version -- the file changed since you read it (expected " + + expectedVersion + + ", current " + + currentVersion + + "); re-read the file, then retry.", + displayPath, + ) + }) +} + +/** + * Unobserved-edit guard: an edit-style write without a prior observation is + * rejected before any I/O. The literal-match / patch logic stays with the + * tools in S4b; this guard only verifies that a read happened first. + * + * Returns Promise because the rejection is total: this function + * never resolves. + */ +export async function unobservedEditGuard(absolutePath: string, displayPath: string): Promise { + throw new GuardRejectedError("File not read yet -- read the file, then retry.", displayPath) +} + +// -- Public API -------------------------------------------------------------- + +/** + * Resolve a relative or absolute path against task.cwd. + * + * path.resolve also normalizes an already-absolute input (collapsing "." / ".." + * segments and trailing separators), so the key always matches the + * ObservationRegistry key recorded at read time (ReadFileTool observes under + * path.resolve(task.cwd, relPath)) and two spellings of one file share one + * FIFO chain. + */ +function resolveAbsolutePath(task: Task, relPathOrAbsolute: string): string { + return path.resolve(task.cwd, relPathOrAbsolute) +} + +/** + * Reject a target that is not inside the task's workspace, before anything is + * queued or touched. path.resolve keeps an absolute input unchanged and collapses + * ".." segments, so a model-supplied string forwarded verbatim can name any path + * on the machine. The rooignore rules, protected-path rules and the user-approval + * flow live in the tool layer; this is the containment line inside the publish + * helper itself, so a caller that forgets them cannot publish outside the + * workspace by accident. + */ +function isInside(root: string, target: string): boolean { + const relative = path.relative(root, target) + return !( + relative === "" || relative === ".." || relative.startsWith(".." + path.sep) || path.isAbsolute(relative) + ) +} + +function assertInsideWorkspace(task: Task, absolutePath: string, displayPath: string): void { + if (!isInside(path.resolve(task.cwd), absolutePath)) { + throw new GuardRejectedError( + `Path resolves outside the workspace -- write inside the workspace, then retry.`, + displayPath, + ) + } +} + +/** + * The lexical check above cannot see a symlink whose referent leaves the workspace, and + * the publish resolves through that link. Resolve both sides the same way and compare + * again. Only a missing TARGET is walked up to the nearest existing ancestor (a create + * has no target yet); a workspace that cannot be resolved - for any reason, ENOENT + * included - is rejected rather than falling back to the lexical decision, because the + * lexical decision is exactly what a symlink defeats. An unresolvable root means there + * is no canonical container to check against, so the write is refused instead of + * published on a weaker guarantee. + * + * The check also records the identity (dev, ino) of every directory it walked from the + * workspace root down to the target's parent. expectedResolvedPath pins the NAME that + * gets published; it cannot notice a parent directory being swapped for a link. The pin + * lets the guard notice that. + */ +async function assertCanonicalInsideWorkspace( + task: Task, + absolutePath: string, + displayPath: string, +): Promise { + let workspaceRoot: string + try { + workspaceRoot = await fs.realpath(path.resolve(task.cwd)) + } catch { + throw new GuardRejectedError( + "Workspace could not be resolved, so this write cannot be checked against it -- retry with a path inside the workspace.", + displayPath, + ) + } + const target = await realpathNearest(absolutePath, displayPath) + if (!isInside(workspaceRoot, target)) { + throw new GuardRejectedError( + `Path resolves through a link to outside the workspace -- write a real file inside the workspace, then retry.`, + displayPath, + ) + } + return { target, ancestors: await ancestorIdentities(workspaceRoot, target) } +} + +/** + * The directories between the canonical workspace root and the target's parent, each + * with the identity it had when the write was authorized. A component that does not + * exist yet (a create into a directory that will be made by the publish) has no + * identity to pin, so it is skipped; every component that DID exist is pinned. + */ +async function ancestorIdentities(root: string, target: string): Promise { + const parent = path.dirname(target) + const relative = path.relative(root, parent) + const chain: string[] = [root] + if (relative && relative !== "." && !relative.startsWith(".." + path.sep)) { + let cursor = root + for (const segment of relative.split(path.sep)) { + cursor = path.join(cursor, segment) + chain.push(cursor) + } + } + const pinned: DirectoryIdentity[] = [] + for (const dir of chain) { + const stat = await fs.stat(dir, { bigint: true }).catch(() => undefined) + if (stat) { + pinned.push({ dir, dev: stat.dev, ino: stat.ino }) + } + } + return pinned +} + +/** + * What the canonical containment check decided, and the directory identities that + * decision was made about. The publish has to be refused when either drifts. + */ +export type AuthorizedTarget = { + target: string + ancestors: DirectoryIdentity[] +} + +async function realpathNearest(target: string, displayPath: string): Promise { + const lexical = path.resolve(target) + try { + return await fs.realpath(lexical) + } catch (error: unknown) { + if (errorCode(error) !== "ENOENT") { + throw new GuardRejectedError( + "Path could not be resolved, so it cannot be checked against the workspace -- retry with a path inside the workspace.", + displayPath, + ) + } + const missing: string[] = [] + let ancestor = lexical + while (true) { + const parent = path.dirname(ancestor) + if (parent === ancestor) { + return lexical + } + missing.push(path.basename(ancestor)) + ancestor = parent + try { + const real = await fs.realpath(ancestor) + return path.join(real, ...missing.reverse()) + } catch (innerError: unknown) { + if (errorCode(innerError) !== "ENOENT") { + throw new GuardRejectedError( + "Path could not be resolved, so it cannot be checked against the workspace -- retry with a path inside the workspace.", + displayPath, + ) + } + // "Missing" has two meanings and only one of them is benign. A directory + // that has not been created yet is fine - the publish makes it. A component + // that EXISTS as a symlink whose referent is gone is a dangling link: the + // lexical name would be re-joined onto a container that points elsewhere + // (or nowhere), and the publish would then create the file outside the + // directory this check authorized. + const asLink = await fs.lstat(ancestor, { bigint: true }).catch(() => undefined) + if (asLink?.isSymbolicLink()) { + throw new GuardRejectedError( + `Path runs through a link (${ancestor}) that does not resolve -- retry with a path inside the workspace.`, + displayPath, + ) + } + } + } + } +} + +/** + * Guarded write entry point. + * + * 1. Resolves the absolute path against task.cwd. + * 2. Consults the task's S2 observation registry to pick the guard: + * - unobserved + create/update: createIfAbsent (rejects if it exists); + * - observed + create on a file that vanished after the read: recreate; + * - observed otherwise: replaceIfVersion (CAS on the S1 version token); + * - unobserved + edit: unobservedEditGuard. + * 3. A full-file replacement ("update", or a "create" whose target still + * exists) additionally requires a complete observation: a partial read + * (slice, range, truncated, indentation block) authorizes targeted edits + * only, never a full-file overwrite of the existing content. + * 4. Runs the chosen guard on the per-path FIFO chain so concurrent writes to + * the same path are deterministically ordered. + * 5. After a successful publish, refreshes the observation with the new + * on-disk token (complete) so consecutive writes by the same task do not + * fail stale against the version they just published. + */ +export async function guardedWrite( + task: Task, + relPathOrAbsolute: string, + content: string | Uint8Array, + kind: GuardedWriteKind = "update", + // Optional completeness for the refresh. A tool that built its content from a + // view of another file must carry that view's completeness through the publish + // instead of claiming completeness for lines it never read. + completeOverride?: boolean, +): Promise { + const absolutePath = resolveAbsolutePath(task, relPathOrAbsolute) + // Model-facing path: the caller's own spelling, not the resolved absolute + // path. The guard key stays absolute, but a rejection must not put a + // user-specific absolute path into the model's context. + const displayPath = relPathOrAbsolute + + // Captured before the FIRST await in this function. The chain is FIFO, so this write + // may not run until long after it was submitted, and task.abort can be raised and then + // cleared by a resume in the meantime; the generation is what tells the two apart. + // Capturing it after the containment awaits would leave a cancel that lands during + // those awaits invisible: the write would capture the POST-cancel generation, sail + // through the dequeue comparison, and publish work that belongs to the cancelled run. + const cancellationGeneration = task.cancellationGeneration + if (task.abort) { + throw new GuardRejectedError( + "Task was cancelled before this write ran -- the queued publish is not performed.", + displayPath, + ) + } + + // Containment is decided before the link is queued: a write that would land + // outside the workspace must not take a slot on the FIFO chain, take the file + // lock, or touch the filesystem at all. + assertInsideWorkspace(task, absolutePath, displayPath) + // Bound to the task and the caller's spelling so the guard can re-run the same + // decision under the lock, immediately before the publish. The first call records + // what was authorized; every later call has to agree with it, or the publish is + // acting on a decision that was never made about the file now at this name. + let pin: AuthorizedTarget | undefined + const verifyTarget = async (): Promise => { + const fresh = await assertCanonicalInsideWorkspace(task, absolutePath, displayPath) + if (!pin) { + pin = fresh + return fresh + } + if (fresh.target !== pin.target) { + throw new GuardRejectedError( + "Path changed between the containment check and the publish -- nothing was written.", + displayPath, + ) + } + for (const expected of pin.ancestors) { + const current = await fs.stat(expected.dir, { bigint: true }).catch(() => undefined) + if (!current || current.dev !== expected.dev || current.ino !== expected.ino) { + throw new GuardRejectedError( + "A directory on the authorized path was replaced after this write was checked -- nothing was written.", + displayPath, + ) + } + } + return fresh + } + await verifyTarget() + + return enqueue(absolutePath, async () => { + // Cancellation is checked when the link is dequeued, not when it was enqueued: + // a write queued before an abort can still reach its turn on the chain after the + // task is gone, and the caller has already reported the write to the model. The + // generation is compared as well because abort is a mutable flag: a cancel followed + // by a resume while this link waited leaves abort false again, and the write still + // belongs to the cancelled run. + if (task.abort || task.cancellationGeneration !== cancellationGeneration) { + throw new GuardRejectedError( + "Task was cancelled before this write ran -- the queued publish is not performed.", + displayPath, + ) + } + const obs = task.observationRegistry.get(absolutePath) + // A targeted edit authorizes only the view the model saw, so a partial + // observation stays partial; a full-file publish is complete. + let staysPartial = false + // Token the guard read under the lock, so the refresh records the token + // this write published rather than a peer writer's. + let publishedToken: string | undefined + + if (kind === "edit") { + // Edit-style writes require a prior read: no observation, no write. + // A targeted edit only authorizes the view the model saw, so a + // partial observation is valid for the edit itself; the version + // check still rejects a file that moved since the read. + if (obs === undefined) { + await unobservedEditGuard(absolutePath, displayPath) + } else { + publishedToken = await replaceIfVersion( + absolutePath, + obs.version, + content, + displayPath, + () => task.abort || task.cancellationGeneration !== cancellationGeneration, + verifyTarget, + ) + staysPartial = obs.complete === false + } + } else { + // "create" or "update" publish a full file built on the model's + // content. A replacement of an existing target -- an "update", or a + // "create" whose target is still on disk -- therefore requires a + // complete observation: a slice, range, truncated, or + // indentation-block read only authorizes the view the model saw, and + // publishing over the existing file would silently drop everything + // the model never read, so the guard fails closed with a + // re-read-the-whole-file remediation. A fresh create (absent target) + // needs no prior read and stays allowed. + const absent = kind === "create" && (await fileIsAbsent(absolutePath)) + if (!absent && obs !== undefined && obs.complete === false) { + throw new GuardRejectedError( + "File was only partially read (line slice, range, truncated view, or indentation block) -- " + + "a full-file replacement needs the complete content; re-read the whole file, then retry.", + displayPath, + ) + } + + if (obs === undefined) { + // Never read: only an absent target may be created. + publishedToken = await createIfAbsent(absolutePath, content, displayPath, () => task.abort || task.cancellationGeneration !== cancellationGeneration, verifyTarget) + } else if (absent) { + // A "create" on a file that vanished after the read recreates it. + publishedToken = await createIfAbsent(absolutePath, content, displayPath, () => task.abort || task.cancellationGeneration !== cancellationGeneration, verifyTarget) + } else { + // The version recorded at read time must still match the on-disk + // token. + publishedToken = await replaceIfVersion( + absolutePath, + obs.version, + content, + displayPath, + () => task.abort || task.cancellationGeneration !== cancellationGeneration, + verifyTarget, + ) + } + } + + // A publish changes the on-disk token (the rename changes ino, size, and + // mtime). The model just wrote the full content, so refresh the + // observation with the new token: a consecutive write by the same task + // must not fail stale against the version it just published. + // The guard already read the token under the lock; a failed stat after a + // successful publish only skips the refresh, it does not undo the publish. + if (publishedToken !== undefined) { + // Refresh with the new token, keeping the completeness the guard + // established: a partial observation that authorized a targeted edit + // must stay partial, otherwise a later full-file replacement would + // publish content built from the slice alone. + task.observationRegistry.observe(absolutePath, publishedToken, completeOverride ?? !staysPartial) + } + }) +} + +/** + * Reset the per-path tail-promise chains (test hook). + */ +export function resetChain(): void { + pendingChains.clear() +} diff --git a/src/eslint-suppressions.json b/src/eslint-suppressions.json index 583485c628..d607509cdc 100644 --- a/src/eslint-suppressions.json +++ b/src/eslint-suppressions.json @@ -976,7 +976,7 @@ }, "core/tools/__tests__/readFileTool.spec.ts": { "@typescript-eslint/no-explicit-any": { - "count": 98 + "count": 96 } }, "core/tools/__tests__/runSlashCommandTool.spec.ts": { @@ -1716,7 +1716,7 @@ }, "utils/safeWriteJson.ts": { "@typescript-eslint/no-explicit-any": { - "count": 4 + "count": 3 } }, "utils/tts.ts": { diff --git a/src/integrations/misc/__tests__/indentation-reader.spec.ts b/src/integrations/misc/__tests__/indentation-reader.spec.ts index d46cb54277..e9b27e7191 100644 --- a/src/integrations/misc/__tests__/indentation-reader.spec.ts +++ b/src/integrations/misc/__tests__/indentation-reader.spec.ts @@ -1,4 +1,5 @@ import { describe, it, expect } from "vitest" +import { MAX_LINE_LENGTH } from "../../../core/prompts/tools/native-tools/read_file" import { parseLines, formatWithLineNumbers, @@ -279,11 +280,45 @@ describe("readWithSlice", () => { expect(result.wasTruncated).toBe(true) }) + it("reports a clipped line separately from omitted lines", () => { + // Every line is returned, but formatWithLineNumbers clips a line longer + // than MAX_LINE_LENGTH, so the model did not see the whole file. + const lines = ["x".repeat(MAX_LINE_LENGTH + 10), "short"].join("\n") + const result = readWithSlice(lines, 0, 10) + + expect(result.returnedLines).toBe(2) + expect(result.wasTruncated).toBe(false) + expect(result.hasClippedLines).toBe(true) + }) + + it("keeps a slice complete when a line is exactly at the length cap", () => { + // formatWithLineNumbers clips only lines strictly longer than the cap, so a + // line at exactly MAX_LINE_LENGTH is shown in full and the read is complete. + const lines = ["x".repeat(MAX_LINE_LENGTH), "short"].join("\n") + const result = readWithSlice(lines, 0, 10) + + expect(result.returnedLines).toBe(2) + expect(result.wasTruncated).toBe(false) + expect(result.hasClippedLines).toBe(false) + }) + + it("flags clipping when any line is clipped, not only when every line is", () => { + // The first line is clipped and the second is shown in full: some lines are + // a partial view even though every line was returned. + const lines = ["y".repeat(MAX_LINE_LENGTH + 1), "short"].join("\n") + const result = readWithSlice(lines, 0, 10) + + expect(result.returnedLines).toBe(2) + expect(result.hasClippedLines).toBe(true) + }) + it("should handle offset beyond file end", () => { const result = readWithSlice(SIMPLE_CODE, 1000, 10) expect(result.returnedLines).toBe(0) expect(result.content).toContain("Error") + // No line was returned, so nothing could have been clipped. + expect(result.hasClippedLines).toBe(false) }) it("should handle negative offset", () => { @@ -297,6 +332,14 @@ describe("readWithSlice", () => { // ─── readWithIndentation Tests ──────────────────────────────────────────────── describe("readWithIndentation", () => { + it("reports an out-of-range anchor as an error with no clipping", () => { + const result = readWithIndentation(SIMPLE_CODE, { anchorLine: 1000 }) + + expect(result.content).toContain("out of range") + expect(result.returnedLines).toBe(0) + expect(result.hasClippedLines).toBe(false) + }) + describe("basic block extraction", () => { it("should extract content around the anchor line", () => { const result = readWithIndentation(PYTHON_CODE, { diff --git a/src/integrations/misc/indentation-reader.ts b/src/integrations/misc/indentation-reader.ts index aecabd5982..5cbd23d168 100644 --- a/src/integrations/misc/indentation-reader.ts +++ b/src/integrations/misc/indentation-reader.ts @@ -58,8 +58,10 @@ export interface IndentationReadResult { totalLines: number /** Lines actually returned */ returnedLines: number - /** Whether output was truncated due to limit */ + /** Whether output was truncated because lines were omitted */ wasTruncated: boolean + /** Whether any returned line was clipped by the per-line length cap */ + hasClippedLines?: boolean } // ─── Constants ──────────────────────────────────────────────────────────────── @@ -306,6 +308,7 @@ export function readWithIndentation(content: string, options: IndentationReadOpt totalLines, returnedLines: 0, wasTruncated: false, + hasClippedLines: false, } } @@ -448,6 +451,7 @@ export function readWithSlice( totalLines, returnedLines: 0, wasTruncated: false, + hasClippedLines: false, } } @@ -455,6 +459,11 @@ export function readWithSlice( const endIdx = Math.min(offset + limit, totalLines) const selectedLines = lines.slice(offset, endIdx) const wasTruncated = endIdx < totalLines + // A returned line can still be a partial view: formatWithLineNumbers clips a + // line longer than MAX_LINE_LENGTH, so a slice that returned every line may + // still hide content. Clipping is reported separately from omission so the + // caller does not suggest a next offset that is beyond the file. + const hasClippedLines = selectedLines.some((line) => line.content.length > MAX_LINE_LENGTH) // Format output const formattedContent = formatWithLineNumbers(selectedLines) @@ -465,5 +474,6 @@ export function readWithSlice( totalLines, returnedLines: selectedLines.length, wasTruncated, + hasClippedLines, } } diff --git a/src/services/file-safety/__tests__/safeWriteText.spec.ts b/src/services/file-safety/__tests__/safeWriteText.spec.ts new file mode 100644 index 0000000000..05b3bd1f37 --- /dev/null +++ b/src/services/file-safety/__tests__/safeWriteText.spec.ts @@ -0,0 +1,1479 @@ +import * as fs from "fs/promises" +import type { BigIntStats } from "fs" +import * as fsSync from "fs" +import { execFile } from "child_process" +import type { ChildProcess } from "child_process" +import * as path from "path" + +import { + PostCommitDurabilityError, + resolveLockKey, + safeWriteText, + StagingPathError, + TargetExistsError, + TargetMovedError, + AncestorReplacedError, + OrphanedBackupError, + type SafeWriteTextOptions, +} from "../safeWriteText" + +// Full mock for fs/promises — all methods are vi.fn() stubs +vi.mock("fs/promises", () => ({ + mkdir: vi.fn(), + access: vi.fn(), + rename: vi.fn(), + link: vi.fn(), + copyFile: vi.fn(), + chmod: vi.fn(), + unlink: vi.fn(), + rmdir: vi.fn(), + realpath: vi.fn(), + stat: vi.fn(), + lstat: vi.fn(), + readlink: vi.fn(), +})) + +// Full mock for fs — all sync methods are vi.fn() stubs. Stats is a bare +// class stub so tests can build minimal Stats stand-ins via its prototype. +vi.mock("fs", () => ({ + // Mirrors Node's value; the no-replace fallback passes it to copyFile. + constants: { COPYFILE_EXCL: 1 }, + openSync: vi.fn(), + writeSync: vi.fn(), + closeSync: vi.fn(), + mkdirSync: vi.fn(), + fsyncSync: vi.fn(), + chmodSync: vi.fn(), + fchmodSync: vi.fn(), + statSync: vi.fn(), + Stats: class Stats {}, +})) + +// Mock child_process.execFile (callback-based — must invoke callback to resolve) +vi.mock("child_process", () => ({ + execFile: vi.fn((cmd, args, opts, cb) => { + if (typeof cb === "function") cb(null) + }), +})) + +// Minimal stand-in for the ChildProcess that callback-form execFile returns. +const fakeChild = { kill: () => true } as unknown as ChildProcess + +// Helper that mirrors safeWriteText's path resolution exactly +function _resolvedTarget(filePath: string): string { + return path.resolve(filePath) +} +function _dirPath(filePath: string): string { + return path.dirname(_resolvedTarget(filePath)) +} +// Minimal Stats stand-in: the SUT only reads `.mode` from it. +// Async lstat stand-in: the SUT only asks whether the path is a link or a file. +// Built on the Stats prototype so the mock value still satisfies fsSync.Stats. +function _fileStats(isLink: boolean): fsSync.Stats { + const s = Object.create(fsSync.Stats.prototype) as fsSync.Stats + s.isSymbolicLink = () => isLink + s.isFile = () => !isLink + return s +} + +function mockDefaults(): void { + vi.resetAllMocks() + // After resetAllMocks, vi.fn() returns undefined — restore promise defaults. + vi.mocked(fs.mkdir).mockResolvedValue(undefined) + vi.mocked(fs.access).mockResolvedValue(undefined) + vi.mocked(fs.rename).mockResolvedValue(undefined) + vi.mocked(fs.link).mockResolvedValue(undefined) + vi.mocked(fs.unlink).mockResolvedValue(undefined) + vi.mocked(fs.rmdir).mockResolvedValue(undefined) + // Existing-target default: a regular 0o644 file. + vi.mocked(fsSync.statSync).mockReturnValue(_stats(0o644)) + // Staged-file default: a regular file, not a link, so a caller-supplied + // tempPath passes the location and file-type check by default. + vi.mocked(fs.lstat).mockResolvedValue(_fileStats(false)) + // Ancestor-identity pin: default to one stable directory identity so the pin + // passes unless a test overrides it. + vi.mocked(fs.stat).mockResolvedValue(_dirIdentity(100n)) +} + +// BigIntStats stand-in for the ancestor pin: the SUT reads only dev/ino off it. +// BigIntStats is class-backed with no public constructor, so this is a +// last-resort double assertion (test-local, per AGENTS.md). +function _dirIdentity(ino: bigint): BigIntStats { + return { dev: 1n, ino } as unknown as BigIntStats +} +function _stats(mode: number): fsSync.Stats { + const s = Object.create(fsSync.Stats.prototype) as fsSync.Stats + Object.assign(s, { mode }) + return s +} + +// ── Test 1: staging file created then cleaned after success ──────────────── + +describe("safeWriteText", () => { + beforeEach(() => { + mockDefaults() + // Default sync-write behaviour: report that all requested bytes were + // written. The Buffer overload passes (fd, buffer, offset, length), + // so the fourth argument is the requested length. + vi.mocked(fsSync.writeSync).mockImplementation((...args: unknown[]) => + typeof args[3] === "number" ? args[3] : 0, + ) + }) + + describe("staging and cleanup", () => { + it("creates a temp file in the staging dir, fsyncs it, renames to target, and cleans up on success", async () => { + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + vi.mocked(fsSync.openSync).mockReturnValue(1) // fd=1 + vi.mocked(fsSync.closeSync).mockReturnValue(undefined) + + await safeWriteText(targetPath, "hello world", { platform: "linux" }) + + // staging dir was created with private permissions — use + // stringContaining to handle Windows path resolution + expect(fsSync.mkdirSync).toHaveBeenCalledWith(expect.stringContaining(".file-safety-staging"), { + recursive: true, + mode: 0o700, + }) + // a pre-existing staging dir is repaired to private permissions too + expect(fsSync.chmodSync).toHaveBeenCalledWith(expect.stringContaining(".file-safety-staging"), 0o700) + + // temp file was opened for writing with the existing target's mode + // (default 0o644 from the statSync default mock) + expect(fsSync.openSync).toHaveBeenCalledWith(expect.stringContaining("safeWriteText_"), "w", 0o644) + + // content was written as a buffer (partial-write loop, full write) + expect(fsSync.writeSync).toHaveBeenCalledWith(1, Buffer.from("hello world", "utf8"), 0, 11) + + // fsync (sync form) was called on the fd + expect(fsSync.fsyncSync).toHaveBeenCalledWith(1) + + // file was closed + expect(fsSync.closeSync).toHaveBeenCalledWith(1) + + // atomic rename happened — realpath mock returns targetPath, so that's the dest + expect(fs.rename).toHaveBeenCalledWith(expect.stringContaining("safeWriteText_"), targetPath) + + // no unlink of temp (it's now the committed file; DACL skipped via platform:linux) + expect(fs.unlink).not.toHaveBeenCalled() + }) + + it("removes the now-empty staging directory after a successful self-staged commit", async () => { + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + vi.mocked(fsSync.openSync).mockReturnValue(1) + + await safeWriteText(targetPath, "hello", { platform: "linux" }) + + // the staging subdir is removed best-effort after the commit rename + // (stringContaining: the SUT and the test helper resolve Windows + // drive-relative paths differently, as in the existing staging tests) + expect(fs.rmdir).toHaveBeenCalledTimes(1) + expect(fs.rmdir).toHaveBeenCalledWith(expect.stringContaining(".file-safety-staging")) + // the win32 DACL restore gate must stay closed on other platforms: + // no icacls save or restore is attempted + expect(execFile).not.toHaveBeenCalled() + }) + + it("still removes the staging directory when no options are supplied at all", async () => { + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + vi.mocked(fsSync.openSync).mockReturnValue(1) + + // options is undefined: the self-staged check and the optional-chained + // DACL runner lookup must not dereference it + await expect(safeWriteText(targetPath, "hello")).resolves.toBeUndefined() + + expect(fs.rmdir).toHaveBeenCalledTimes(1) + expect(fs.rmdir).toHaveBeenCalledWith(expect.stringContaining(".file-safety-staging")) + if (process.platform === "win32") { + // default platform is win32: the DACL save + restore still ran + // through the default icacls path (options?.execFileRunner must + // not throw when options is undefined) + expect(vi.mocked(execFile)).toHaveBeenCalledTimes(2) + expect(vi.mocked(fs.unlink)).toHaveBeenCalledWith(expect.stringContaining("safeWriteText.acl")) + } + }) + + it("does not remove the staging directory when the caller supplies its own tempPath", async () => { + const targetPath = "/tmp/test-dir/target.txt" + const callerTemp = "/tmp/test-dir/caller-staged.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + vi.mocked(fsSync.openSync).mockReturnValue(1) + + await safeWriteText(targetPath, "hello", { platform: "linux", tempPath: callerTemp }) + + // the caller owns its temp file's directory; safeWriteText must not + // rmdir a directory it did not create + expect(fs.rmdir).not.toHaveBeenCalled() + }) + + it("a failed staging-dir removal never fails the committed write", async () => { + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + vi.mocked(fsSync.openSync).mockReturnValue(1) + vi.mocked(fs.rmdir).mockRejectedValue(Object.assign(new Error("ENOTEMPTY"), { code: "ENOTEMPTY" })) + + await expect(safeWriteText(targetPath, "hello", { platform: "linux" })).resolves.toBeUndefined() + + // the commit rename still happened and the rmdir error was swallowed + expect(fs.rename).toHaveBeenCalledWith(expect.stringContaining(".file-safety-staging"), targetPath) + expect(fs.rmdir).toHaveBeenCalledTimes(1) + expect(fs.rmdir).toHaveBeenCalledWith(expect.stringContaining(".file-safety-staging")) + }) + + it("gives each self-staged write its own staging directory so a concurrent write cannot remove it", async () => { + const targetA = "/tmp/test-dir/target-a.txt" + const targetB = "/tmp/test-dir/target-b.txt" + vi.mocked(fs.realpath).mockImplementation((p) => Promise.resolve(p as string)) + vi.mocked(fsSync.openSync).mockReturnValue(1) + + await safeWriteText(targetA, "a", { platform: "linux" }) + await safeWriteText(targetB, "b", { platform: "linux" }) + + // Two self-staged writes in the same directory must not share one staging + // directory: the first write's best-effort rmdir would otherwise delete the + // directory the second write had created but not yet opened (ENOENT on openSync). + const created = vi.mocked(fsSync.mkdirSync).mock.calls.map((c) => String(c[0])) + const staging = created.filter((p) => p.includes(".file-safety-staging_")) + expect(staging).toHaveLength(2) + expect(staging[0]).not.toBe(staging[1]) + // Uniqueness comes from the documented name shape + // /.file-safety-staging__: pinning the shape + // keeps the separator and the random suffix meaningful, not just the prefix. + for (const dir of staging) { + expect(dir).toMatch(/\.file-safety-staging_\d+_[a-z0-9]+$/) + } + const removed = vi.mocked(fs.rmdir).mock.calls.map((c) => String(c[0])) + expect(removed).toEqual([staging[0], staging[1]]) + }) + + it("removes its own staging directory when a self-staged write fails", async () => { + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + vi.mocked(fsSync.openSync).mockReturnValue(1) + vi.mocked(fs.rename).mockRejectedValue(Object.assign(new Error("EACCES"), { code: "EACCES" })) + + await expect(safeWriteText(targetPath, "hello", { platform: "linux" })).rejects.toThrow("EACCES") + + // The failed write's temp file is unlinked, then the directory it + // created is removed — a failed write must not leave an empty + // .file-safety-staging directory behind. + // mkdirSync created this write's staging directory; the temp file lives + // inside it, so the unlink targets a path under that directory. + const staging = vi.mocked(fsSync.mkdirSync).mock.calls.map((c) => String(c[0])) + expect(staging).toHaveLength(1) + expect(fs.unlink).toHaveBeenCalledWith(expect.stringContaining(staging[0])) + expect(fs.rmdir).toHaveBeenCalledWith(staging[0]) + // The directory is only empty after its temp file is gone, so the + // unlink must happen before the rmdir. + expect(vi.mocked(fs.unlink).mock.invocationCallOrder[0]).toBeLessThan( + vi.mocked(fs.rmdir).mock.invocationCallOrder[0], + ) + }) + + it("does not remove a staging directory it did not create when a caller-staged write fails", async () => { + const targetPath = "/tmp/test-dir/target.txt" + const callerTemp = "/tmp/test-dir/caller-staged.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + vi.mocked(fsSync.openSync).mockReturnValue(1) + vi.mocked(fs.rename).mockRejectedValue(Object.assign(new Error("EACCES"), { code: "EACCES" })) + + await expect( + safeWriteText(targetPath, "hello", { platform: "linux", tempPath: callerTemp }), + ).rejects.toThrow("EACCES") + + // The caller owns that directory: only the caller's temp file is cleaned, + // never a rmdir of a directory safeWriteText never created. + expect(fs.unlink).toHaveBeenCalledWith(callerTemp) + expect(fs.rmdir).not.toHaveBeenCalled() + }) + }) + + // ── Test 2: fsync ordering ─────────────────────────────────────────────── + + describe("fsync ordering", () => { + it("calls fsync on the fd before close, and rename after close", async () => { + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + vi.mocked(fsSync.openSync).mockReturnValue(1) + + await safeWriteText(targetPath, "data", { platform: "linux" }) + + // Verify call order: openSync(temp) → writeSync → fsyncSync(temp) + // → closeSync(temp) → rename. On POSIX the parent directory is then + // opened and fsynced after the commit rename, so openSync/fsyncSync/ + // closeSync each have a second (directory) call. + expect(vi.mocked(fsSync.openSync).mock.calls.length).toBe(2) + expect(vi.mocked(fsSync.writeSync).mock.calls.length).toBe(1) + expect(vi.mocked(fsSync.fsyncSync).mock.calls.length).toBe(2) + expect(vi.mocked(fsSync.closeSync).mock.calls.length).toBe(2) + + // the temp file was fully closed before the commit rename + expect(vi.mocked(fsSync.closeSync).mock.calls[0][0]).toBe(1) + expect(fs.rename).toHaveBeenCalledWith(expect.stringContaining("safeWriteText_"), targetPath) + // The title promises the order, so compare the invocations rather than + // only count them: a rename before closeSync, or a close before fsync, + // would not be a durable commit. + const fsyncOrder = vi.mocked(fsSync.fsyncSync).mock.invocationCallOrder[0] + const closeOrder = vi.mocked(fsSync.closeSync).mock.invocationCallOrder[0] + const renameOrder = vi.mocked(fs.rename).mock.invocationCallOrder[0] + expect(fsyncOrder).toBeLessThan(closeOrder) + expect(closeOrder).toBeLessThan(renameOrder) + }) + }) + + // ── Test 3: simulated failure between write and rename leaves target intact ── + + describe("crash/torn-write safety", () => { + it("simulated failure between fsync and rename leaves the target byte-identical and no temp left behind", async () => { + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + vi.mocked(fsSync.openSync).mockReturnValue(1) + vi.mocked(fs.rename).mockRejectedValue(new Error("ENOSPC")) + + await expect(safeWriteText(targetPath, "new data", { platform: "linux" })).rejects.toThrow("ENOSPC") + + // rename was attempted (the failure point) + expect(fs.rename).toHaveBeenCalledWith(expect.stringContaining("safeWriteText_"), targetPath) + + // temp file was cleaned up on failure + expect(fs.unlink).toHaveBeenCalledWith(expect.stringContaining("safeWriteText_")) + + // backup was NOT created (backup:false by default), so target is untouched + // The only rename call was temp→target, not a rollback rename + expect(fs.rename).toHaveBeenCalledTimes(1) + }) + + it("a post-commit backup cleanup failure is non-fatal: the target stays committed and no temp is left behind", async () => { + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + vi.mocked(fsSync.openSync).mockReturnValue(1) + // The post-commit backup unlink (SUT step 6) fails — the write must + // still succeed; an orphaned backup is the documented acceptable + // outcome, so the failure is swallowed instead of rolling back. + vi.mocked(fs.unlink).mockRejectedValueOnce(new Error("EPERM")) + + await safeWriteText(targetPath, "data", { backup: true, platform: "linux" }) + + // the commit rename (temp -> target) still happened; it is the only rename + expect(fs.rename).toHaveBeenCalledTimes(1) + expect(fs.rename).toHaveBeenCalledWith(expect.stringContaining("safeWriteText_"), targetPath) + + // the failing cleanup was the post-commit backup unlink + expect(fs.unlink).toHaveBeenCalledWith(expect.stringContaining("safeWriteText.bak_")) + + // the staging temp was already committed by the rename; nothing + // temp-shaped is unlinked afterwards + expect(fs.unlink).not.toHaveBeenCalledWith(expect.stringContaining("safeWriteText_")) + }) + }) + + // ── Test 4: backup:true keeps old safeWriteJson semantics incl. rollback ── + + describe("backup:true", () => { + it("copies target -> backup before commit without moving the target, deletes the copy on success", async () => { + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + vi.mocked(fsSync.openSync).mockReturnValue(1) + + await safeWriteText(targetPath, "new data", { backup: true }) + + // target was accessed (exists check) + expect(fs.access).toHaveBeenCalledWith(targetPath) + + // The backup is a copy: the canonical target is never moved away, so readers + // never see a missing file and no later step can clobber a concurrent publish. + expect(fs.copyFile).toHaveBeenCalledWith(targetPath, expect.stringContaining("safeWriteText.bak_")) + expect(fs.rename).not.toHaveBeenCalledWith(targetPath, expect.stringContaining("safeWriteText.bak_")) + + // the only rename is the atomic commit temp -> target + expect(fs.rename).toHaveBeenCalledTimes(1) + expect(fs.rename).toHaveBeenCalledWith(expect.stringContaining("safeWriteText_"), targetPath) + + // backup copy was deleted on success + expect(fs.unlink).toHaveBeenCalledWith(expect.stringContaining("safeWriteText.bak_")) + }) + + it("a failed commit does not move the target, so nothing has to be rolled back", async () => { + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + vi.mocked(fsSync.openSync).mockReturnValue(1) + // The commit rename is the only rename in the flow and it fails. + vi.mocked(fs.rename).mockRejectedValue(new Error("ENOSPC")) + + await expect(safeWriteText(targetPath, "new data", { backup: true })).rejects.toThrow("ENOSPC") + + // The target never left its path, so there is no restore rename and the + // pre-write content is still what a reader sees at targetPath. + expect(fs.rename).toHaveBeenCalledTimes(1) + expect(fs.copyFile).toHaveBeenCalledWith(targetPath, expect.stringContaining("safeWriteText.bak_")) + + // Both the backup copy and the staging temp are cleaned up on failure. + expect(fs.unlink).toHaveBeenCalledWith(expect.stringContaining("safeWriteText.bak_")) + expect(fs.unlink).toHaveBeenCalledWith(expect.stringContaining("safeWriteText_")) + }) + + it("creates the backup privately before its content exists, then fsyncs it", async () => { + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + vi.mocked(fsSync.openSync).mockReturnValue(1) + + await safeWriteText(targetPath, "new data", { backup: true }) + + // The destination must exist with a private mode before copyFile writes anything + // into it: copyFile chooses the destination mode itself, so a restrictive target + // could otherwise leave a group/world-readable copy that a later chmod cannot + // undo. "wx" also means a pre-existing path is never silently reused. + const seedOpen = vi.mocked(fsSync.openSync).mock.calls.find(function (call) { + return String(call[0]).includes("safeWriteText.bak_") && call[1] === "wx" + }) + expect(seedOpen).toBeDefined() + expect(seedOpen?.[2]).toBe(0o600) + const seedOrder = vi.mocked(fsSync.openSync).mock.invocationCallOrder[vi.mocked(fsSync.openSync).mock.calls.indexOf(seedOpen!)] + expect(seedOrder).toBeLessThan(vi.mocked(fs.copyFile).mock.invocationCallOrder[0]) + + // The chmod keeps a copied read-only attribute (Windows) from breaking the fsync + // open, and keeps a backup of a permissive file private. + expect(fs.copyFile).toHaveBeenCalledWith(targetPath, expect.stringContaining("safeWriteText.bak_")) + expect(fs.chmod).toHaveBeenCalledWith(expect.stringContaining("safeWriteText.bak_"), 0o600) + expect(vi.mocked(fs.chmod).mock.invocationCallOrder[0]).toBeGreaterThan( + vi.mocked(fs.copyFile).mock.invocationCallOrder[0], + ) + + // The copy is then opened for fsync with the writable flag. + const backupOpen = vi.mocked(fsSync.openSync).mock.calls.find(function (call) { + return String(call[0]).includes("safeWriteText.bak_") && call[1] === "r+" + }) + expect(backupOpen).toBeDefined() + }) + + it("a failed backup flush is reported and leaves no partial backup behind", async () => { + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + vi.mocked(fsSync.openSync).mockReturnValue(1) + // The copy lands, but the fsync of the copy fails: the retained content is not + // known to be durable, so the write must not proceed on a half-written backup. + // The staged temp is fsynced earlier with a different handle, so target the + // backup's fd specifically. + vi.mocked(fsSync.openSync).mockImplementation((p: unknown) => (String(p).includes("safeWriteText.bak_") ? 7 : 1)) + vi.mocked(fsSync.fsyncSync).mockImplementation((fd: unknown) => { + if (fd === 7) { + throw new Error("EIO") + } + }) + + await expect(safeWriteText(targetPath, "new data", { backup: true, platform: "linux" })).rejects.toThrow("EIO") + + // Nothing was published, and the incomplete copy is removed rather than left + // next to the target looking like a usable backup. + expect(fs.rename).not.toHaveBeenCalled() + expect(fs.unlink).toHaveBeenCalledWith(expect.stringContaining("safeWriteText.bak_")) + expect(fs.unlink).toHaveBeenCalledWith(expect.stringContaining("safeWriteText_")) + }) + + it("carries the leftover path when the partial backup cannot be removed either", async () => { + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + vi.mocked(fsSync.openSync).mockImplementation((p: unknown) => + String(p).includes("safeWriteText.bak_") ? 7 : 1, + ) + vi.mocked(fsSync.fsyncSync).mockImplementation((fd: unknown) => { + if (fd === 7) { + throw new Error("EIO") + } + }) + let unlinkAttempts = 0 + vi.mocked(fs.unlink).mockImplementation(async (p: unknown) => { + if (String(p).includes("safeWriteText.bak_")) { + unlinkAttempts++ + } + throw Object.assign(new Error("EPERM"), { code: "EPERM" }) + }) + + // The copy failed and the locked leftover could not be unlinked even after the + // retry. Dropping the path would leave a partial copy of the previous content on + // disk with no reference to it anywhere, so the error carries it. + const error = await safeWriteText(targetPath, "new data", { + backup: true, + platform: "linux", + }).catch((caught: unknown) => caught) + + expect(error).toBeInstanceOf(OrphanedBackupError) + const orphan = error as OrphanedBackupError + expect(orphan.orphanedBackupPath).toContain("safeWriteText.bak_") + expect(orphan.message).toContain("safeWriteText.bak_") + expect(orphan.message).toContain("EPERM") + expect(orphan.originalError).toBeInstanceOf(Error) + expect((orphan.originalError as Error).message).toBe("EIO") + expect(orphan.cause).toBe(orphan.originalError) + expect(unlinkAttempts).toBe(2) + expect(fs.rename).not.toHaveBeenCalled() + }) + + it("a backup copy that fails part-way is removed, not left as a usable-looking backup", async () => { + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + vi.mocked(fsSync.openSync).mockReturnValue(1) + // The destination is seeded with openSync("wx") BEFORE any content exists at it, + // and the copy then fails part-way: the name is there, holding a partial copy of + // nothing usable. Cleanup has to key off the attempt, not off a copy that + // succeeded, or this file outlives the failed write beside the target. + vi.mocked(fs.copyFile).mockRejectedValue(Object.assign(new Error("EIO"), { code: "EIO" })) + + await expect(safeWriteText(targetPath, "new data", { backup: true, platform: "linux" })).rejects.toThrow("EIO") + + // Nothing was published, and the half-written copy is removed rather than left + // next to the target looking like a backup someone could restore. + expect(fs.rename).not.toHaveBeenCalled() + expect(fs.unlink).toHaveBeenCalledWith(expect.stringContaining("safeWriteText.bak_")) + expect(fs.unlink).toHaveBeenCalledWith(expect.stringContaining("safeWriteText_")) + }) + + + + it("backup:true when target does not exist: no backup created, just commit", async () => { + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + vi.mocked(fsSync.openSync).mockReturnValue(1) + // fs.access resolves for dirPath check, but rejects for target check (backup path) + vi.mocked(fs.access).mockImplementation(async (p) => { + if (typeof p === "string" && p.endsWith("target.txt")) throw { code: "ENOENT" } + }) + + await safeWriteText(targetPath, "new data", { backup: true, platform: "linux" }) + + // no backup rename (target didn't exist) + expect(fs.access).toHaveBeenCalledWith(targetPath) + + // only one rename: temp -> target + expect(fs.rename).toHaveBeenCalledTimes(1) + expect(fs.rename).toHaveBeenCalledWith(expect.stringContaining("safeWriteText_"), targetPath) + + // no unlink (no backup to delete; DACL skipped via platform:linux) + expect(fs.unlink).not.toHaveBeenCalled() + }) + }) + + // ── Test 5: win32 DACL path ────────────────────────────────────────────── + + describe("win32 DACL", () => { + it.skipIf(process.platform !== "win32")( + "copies target DACL onto staging file via icacls before rename on Windows", + async () => { + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + await safeWriteText(targetPath, "data", { platform: "win32" }) + + // icacls dump + restore were called (execFile is callback-based mock) + expect(execFile).toHaveBeenCalledTimes(2) + }, + ) + + it("non-win32: DACL path is unreachable when platform is not win32", async () => { + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + vi.mocked(fsSync.openSync).mockReturnValue(1) + + await safeWriteText(targetPath, "data", { platform: "linux" }) + + // icacls was NOT called on non-win32 + expect(execFile).not.toHaveBeenCalled() + }) + + it("win32 DACL failure falls back to plain rename (never fails the write)", async () => { + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + vi.mocked(fsSync.openSync).mockReturnValue(1) + // icacls dump fails — the callback-based mock must invoke cb with an error. + vi.mocked(execFile).mockImplementation((_cmd, _args, _opts, cb) => { + if (typeof cb === "function") cb(new Error("icacls error"), "", "") + return fakeChild + }) + + await safeWriteText(targetPath, "data", { platform: "win32" }) + + // write succeeded despite icacls failure (fallback to plain rename) + expect(fs.rename).toHaveBeenCalledWith(expect.stringContaining(".file-safety-staging"), targetPath) + // one icacls attempt only: a failed DACL apply must not try to restore + expect(execFile).toHaveBeenCalledTimes(1) + }) + + it("win32 DACL: a partial dump left by a failed save is removed and never restored", async () => { + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + vi.mocked(fsSync.openSync).mockReturnValue(1) + // icacls save fails — a real icacls may have written a partial dump + // before erroring, so the dump path must be cleaned up and must never + // be used for a restore. + vi.mocked(execFile).mockImplementation((_cmd, _args, _opts, cb) => { + if (typeof cb === "function") cb(new Error("icacls save error"), "", "") + return fakeChild + }) + + await safeWriteText(targetPath, "data", { platform: "win32" }) + + // write committed; only the save was attempted (no restore from a failed dump) + expect(fs.rename).toHaveBeenCalledWith(expect.stringContaining("safeWriteText_"), targetPath) + expect(fs.rename).toHaveBeenCalledTimes(1) + expect(execFile).toHaveBeenCalledTimes(1) + const saveArgs = vi.mocked(execFile).mock.calls[0]?.[1] + expect(saveArgs?.[1]).toBe("/save") + // the dump path (possibly partially created by icacls) was unlinked + expect(fs.unlink).toHaveBeenCalledWith(expect.stringContaining("safeWriteText.acl")) + }) + + it("win32 DACL save args are [targetPath, /save, dumpPath, /T] before backup rename", async () => { + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + vi.mocked(fsSync.openSync).mockReturnValue(1) + + await safeWriteText(targetPath, "data", { backup: true, platform: "win32" }) + + // icacls was called twice (save + restore) + expect(execFile).toHaveBeenCalledTimes(2) + + // First call: save DACL from target before backup rename + const firstCall = vi.mocked(execFile).mock.calls[0] + expect(firstCall[0]).toBe("icacls") + expect(firstCall[1]).toEqual([targetPath, "/save", expect.stringContaining("safeWriteText.acl"), "/T"]) + + // Second call: restore DACL onto directory after commit rename + const secondCall = vi.mocked(execFile).mock.calls[1] + expect(secondCall[0]).toBe("icacls") + expect(secondCall[1]).toEqual([ + expect.stringContaining("/tmp/test-dir"), + "/restore", + expect.stringContaining("safeWriteText.acl"), + ]) + + // dump file was unlinked after restore + expect(fs.unlink).toHaveBeenCalledWith(expect.stringContaining("safeWriteText.acl")) + }) + + it("win32 DACL: dump is unlinked even when restore fails", async () => { + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + vi.mocked(fsSync.openSync).mockReturnValue(1) + + // icacls save succeeds, restore fails + let callCount = 0 + vi.mocked(execFile).mockImplementation((_cmd, _args, _opts, cb) => { + callCount++ + if (typeof cb === "function") { + cb(callCount === 1 ? null : new Error("icacls restore error"), "", "") + } + return fakeChild + }) + + await safeWriteText(targetPath, "data", { platform: "win32" }) + + // write succeeded despite restore failure (best-effort) + expect(fs.rename).toHaveBeenCalledWith(expect.stringContaining("safeWriteText_"), targetPath) + expect(fs.rename).toHaveBeenCalledTimes(1) + + // dump file was still unlinked in finally + expect(fs.unlink).toHaveBeenCalledWith(expect.stringContaining("safeWriteText.acl")) + }) + + it("win32 DACL: when target does not exist, no save/restore/dump", async () => { + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + vi.mocked(fsSync.openSync).mockReturnValue(1) + + // fs.access rejects for targetPath (ENOENT), but resolves for dirPath + vi.mocked(fs.access).mockImplementation(async (p) => { + if (typeof p === "string" && p.endsWith("target.txt")) throw { code: "ENOENT" } + return undefined + }) + + await safeWriteText(targetPath, "data", { platform: "win32" }) + + // icacls was NOT called (target absent → skip DACL entirely) + expect(execFile).not.toHaveBeenCalled() + + // no dump file created or unlinked + expect(fs.unlink).not.toHaveBeenCalled() + }) + }) + + // ── Test 6: pre-written temp path (tempPath option) ────────────────────── + + describe("pre-written temp path", () => { + it("uses the provided tempPath, fsyncs it, and renames to target", async () => { + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + vi.mocked(fsSync.openSync).mockReturnValue(1) + + const customTempPath = "/tmp/test-dir/custom-temp.tmp" + + // platform:linux skips DACL entirely so this test focuses on tempPath only + await safeWriteText(targetPath, "", { tempPath: customTempPath, platform: "linux" }) + + // openSync was called on the custom temp path (r+ mode for fsync) + expect(fsSync.openSync).toHaveBeenCalledWith(customTempPath, "r+") + + // fsync was called + expect(fsSync.fsyncSync).toHaveBeenCalledWith(1) + + // rename happened — realpath mock returns targetPath + expect(fs.rename).toHaveBeenCalledWith(customTempPath, targetPath) + + // no unlink of custom temp (caller's concern; DACL skipped via platform:linux) + expect(fs.unlink).not.toHaveBeenCalled() + + // a caller-supplied tempPath must not create the staging directory + expect(fsSync.mkdirSync).not.toHaveBeenCalled() + }) + + it("applies the existing target's mode to a caller-supplied tempPath before publishing", async () => { + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + vi.mocked(fsSync.statSync).mockReturnValue(_stats(0o600)) + vi.mocked(fsSync.openSync).mockReturnValue(2) + + const customTempPath = "/tmp/test-dir/custom-temp.tmp" + + await safeWriteText(targetPath, "", { tempPath: customTempPath, platform: "linux" }) + + // the caller-staged temp is fchmod'd to the restrictive target mode so + // the atomic rename cannot widen a 0o600 target (CWE-732 regression) + expect(fsSync.fchmodSync).toHaveBeenCalledWith(2, 0o600) + expect(fsSync.openSync).toHaveBeenCalledWith(customTempPath, "r+") + expect(fs.rename).toHaveBeenCalledWith(customTempPath, targetPath) + }) + + it("keeps the temp's default mode when the target does not exist yet (ENOENT)", async () => { + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + const enoent = Object.assign(new Error("ENOENT: no such file or directory"), { code: "ENOENT" }) + vi.mocked(fsSync.statSync).mockImplementation(() => { + throw enoent + }) + vi.mocked(fsSync.openSync).mockReturnValue(2) + + const customTempPath = "/tmp/test-dir/custom-temp.tmp" + + await safeWriteText(targetPath, "", { tempPath: customTempPath, platform: "linux" }) + + // no existing target, so nothing to preserve and no fchmod on the temp + expect(fsSync.fchmodSync).not.toHaveBeenCalled() + expect(fs.rename).toHaveBeenCalledWith(customTempPath, targetPath) + }) + + it("propagates a non-ENOENT stat failure rather than defaulting the mode (caller-staged)", async () => { + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + const eacces = Object.assign(new Error("EACCES: permission denied"), { code: "EACCES" }) + vi.mocked(fsSync.statSync).mockImplementation(() => { + throw eacces + }) + vi.mocked(fsSync.openSync).mockReturnValue(2) + + const customTempPath = "/tmp/test-dir/custom-temp.tmp" + + // A target that cannot be stat'd is not a fresh target: publishing with + // the default mode would widen a restrictive target through the rename. + await expect( + safeWriteText(targetPath, "", { tempPath: customTempPath, platform: "linux" }), + ).rejects.toThrow("EACCES") + expect(fsSync.fchmodSync).not.toHaveBeenCalled() + expect(fs.rename).not.toHaveBeenCalled() + }) + + it("propagates a non-ENOENT stat failure rather than defaulting the mode (self-staged)", async () => { + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + const eio = Object.assign(new Error("EIO: i/o error"), { code: "EIO" }) + vi.mocked(fsSync.statSync).mockImplementation(() => { + throw eio + }) + + // The mode is read before the temp is opened, so a real I/O failure stops + // the write before anything is staged. + await expect(safeWriteText(targetPath, "hello world", { platform: "linux" })).rejects.toThrow("EIO") + expect(fsSync.openSync).not.toHaveBeenCalled() + expect(fs.rename).not.toHaveBeenCalled() + }) + + it("opens the temp before applying a read-only target's mode (0o444 does not block the open)", async () => { + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + vi.mocked(fsSync.statSync).mockReturnValue(_stats(0o444)) + vi.mocked(fsSync.openSync).mockReturnValue(3) + + const customTempPath = "/tmp/test-dir/custom-temp.tmp" + + await safeWriteText(targetPath, "", { tempPath: customTempPath, platform: "linux" }) + + // a 0o444 target must not make openSync(tempPath, "r+") fail: the mode + // is applied with fchmodSync on the already-open fd, after the open + expect(fsSync.openSync).toHaveBeenCalledWith(customTempPath, "r+") + expect(fsSync.fchmodSync).toHaveBeenCalledWith(3, 0o444) + const openIdx = vi.mocked(fsSync.openSync).mock.invocationCallOrder[0] + const fchmodIdx = vi.mocked(fsSync.fchmodSync).mock.invocationCallOrder[0] + expect(openIdx).toBeLessThan(fchmodIdx) + expect(fs.rename).toHaveBeenCalledWith(customTempPath, targetPath) + }) + + it("applies the existing target's exact mode to the self-staged temp (umask must not narrow it)", async () => { + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + vi.mocked(fsSync.statSync).mockReturnValue(_stats(0o664)) + vi.mocked(fsSync.openSync).mockReturnValue(1) + + await safeWriteText(targetPath, "data", { platform: "linux" }) + + // openSync's creation mode is narrowed by the process umask (0o664 -> 0o644 with + // the common 0o022), and the rename publishes the temp's mode onto the target, + // so the existing target's mode must be applied on the fd before the commit. + expect(fsSync.fchmodSync).toHaveBeenCalledWith(1, 0o664) + const openIdx = vi.mocked(fsSync.openSync).mock.invocationCallOrder[0] + const fchmodIdx = vi.mocked(fsSync.fchmodSync).mock.invocationCallOrder[0] + expect(openIdx).toBeLessThan(fchmodIdx) + expect(fs.rename).toHaveBeenCalledWith(expect.stringContaining("safeWriteText_"), targetPath) + }) + + it("a failed post-commit directory fsync does not roll the backup back over the published content", async () => { + const targetPath = "/tmp/test-dir/target.txt" + const dirPath = path.dirname(targetPath) + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + // The file fd opens normally; the parent-directory open after the commit + // rename fails, which is the post-commit durability failure. + vi.mocked(fsSync.openSync).mockImplementation((target) => { + if (String(target) === dirPath) throw new Error("EBADF") + return 1 + }) + + await expect(safeWriteText(targetPath, "new data", { backup: true, platform: "linux" })).rejects.toThrow(PostCommitDurabilityError) + + // The commit rename already published the new content, and the backup was only + // ever a copy: the target was never moved, so there is nothing to rename back. + expect(fs.copyFile).toHaveBeenCalledWith(targetPath, expect.stringContaining("safeWriteText.bak_")) + expect(fs.rename).toHaveBeenCalledTimes(1) + expect(fs.rename).toHaveBeenCalledWith(expect.stringContaining("safeWriteText_"), targetPath) + + // The durability failure is reported, not swallowed - and the backup copy is not + // left beside the target where no caller could find it. + expect(fs.unlink).toHaveBeenCalledWith(expect.stringContaining("safeWriteText.bak_")) + }) + + it("does not fchmod the self-staged temp for a fresh target", async () => { + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + const enoent = Object.assign(new Error("ENOENT: no such file or directory"), { code: "ENOENT" }) + vi.mocked(fsSync.statSync).mockImplementation(() => { + throw enoent + }) + vi.mocked(fsSync.openSync).mockReturnValue(1) + + await safeWriteText(targetPath, "data", { platform: "linux" }) + + // Nothing exists to preserve: the default creation mode is the intended one. + expect(fsSync.fchmodSync).not.toHaveBeenCalled() + }) + }) + + // ── Test 7: symlink handling (Finding 4 regression test) ───────────────── + + describe("symlink handling", () => { + it("a write through a symlink commits onto the resolved referent, never the link path", async () => { + const linkPath = "/tmp/links/link.txt" + const referentPath = "/tmp/targets/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(referentPath) + vi.mocked(fsSync.openSync).mockReturnValue(1) + + await safeWriteText(linkPath, "new-content", { platform: "linux" }) + + // The commit rename must target the realpath result (the referent), never the link itself — + // that is what guarantees a write through a symlink replaces the referent's content + // and preserves the link. + expect(fs.rename).toHaveBeenCalledWith(expect.stringContaining("safeWriteText_"), referentPath) + expect(fs.rename).not.toHaveBeenCalledWith(expect.anything(), linkPath) + }) + + it("when realpath reports ENOENT (target absent), uses the given path as-is", async () => { + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockRejectedValue(Object.assign(new Error("ENOENT"), { code: "ENOENT" })) + // lstat reports the path itself as absent, so this is a new target and + // the fallback is allowed. + vi.mocked(fs.lstat).mockRejectedValue(Object.assign(new Error("ENOENT"), { code: "ENOENT" })) + vi.mocked(fsSync.openSync).mockReturnValue(1) + + await safeWriteText(targetPath, "data", { platform: "linux" }) + + // rename still happened with the fallback path (path.resolve on /tmp → C:\tmp) + const resolvedFallback = _resolvedTarget(targetPath) + expect(fs.rename).toHaveBeenCalledWith(expect.stringContaining("safeWriteText_"), resolvedFallback) + }) + + it("propagates a dangling symlink instead of writing through the link path", async () => { + // realpath resolves the referent, so a link whose target is missing reports + // ENOENT. Falling back to the link path would replace the symlink with a + // regular file, so the error must propagate and nothing may be committed. + const linkPath = "/tmp/test-dir/dangling-link.txt" + vi.mocked(fs.realpath).mockRejectedValue(Object.assign(new Error("ENOENT"), { code: "ENOENT" })) + const linkStats = Object.create(fsSync.Stats.prototype) as fsSync.Stats + linkStats.isSymbolicLink = () => true + vi.mocked(fs.lstat).mockResolvedValue(linkStats) + vi.mocked(fsSync.openSync).mockReturnValue(1) + + await expect(safeWriteText(linkPath, "data", { platform: "linux" })).rejects.toThrow("ENOENT") + + expect(fs.rename).not.toHaveBeenCalled() + }) + }) + + // ── Test 8: review fixes (permissions, partial writes, resolution, durability) ── + + describe("review fixes", () => { + it("preserves the target's restrictive mode and tolerates a failed staging-dir permission repair", async () => { + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + vi.mocked(fsSync.openSync).mockReturnValue(1) + vi.mocked(fsSync.statSync).mockReturnValue(_stats(0o600)) + // a pre-existing staging dir may fail its best-effort permission repair + vi.mocked(fsSync.chmodSync).mockImplementationOnce(() => { + throw new Error("EACCES") + }) + + await safeWriteText(targetPath, "secret", { platform: "linux" }) + + // the staging file inherits the target's 0o600 mode and the write commits + expect(fsSync.openSync).toHaveBeenCalledWith(expect.stringContaining("safeWriteText_"), "w", 0o600) + expect(fs.rename).toHaveBeenCalledWith(expect.stringContaining("safeWriteText_"), targetPath) + }) + + it("falls back to the 0o644 default when the target does not exist yet", async () => { + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + vi.mocked(fsSync.openSync).mockReturnValue(1) + vi.mocked(fsSync.statSync).mockImplementation(() => { + throw Object.assign(new Error("ENOENT"), { code: "ENOENT" }) + }) + + await safeWriteText(targetPath, "fresh", { platform: "linux" }) + + expect(fsSync.openSync).toHaveBeenCalledWith(expect.stringContaining("safeWriteText_"), "w", 0o644) + }) + + it("loops on short writes until the full content is durable before fsync", async () => { + const targetPath = "/tmp/test-dir/target.txt" + const content = "0123456789" // 10 bytes + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + vi.mocked(fsSync.openSync).mockReturnValue(1) + const buffer = Buffer.from(content, "utf8") + // first write (offset 0) reports 4 bytes (short write); the loop continues + vi.mocked(fsSync.writeSync).mockImplementation((...args: unknown[]) => + args[2] === 0 ? 4 : typeof args[3] === "number" ? args[3] : 0, + ) + + await safeWriteText(targetPath, content, { platform: "linux" }) + + // [0,10) reports 4 bytes, then [4,10) writes the remaining 6 + expect(fsSync.writeSync).toHaveBeenCalledTimes(2) + expect(fsSync.writeSync).toHaveBeenNthCalledWith(1, 1, buffer, 0, 10) + expect(fsSync.writeSync).toHaveBeenNthCalledWith(2, 1, buffer, 4, 6) + expect(fsSync.fsyncSync).toHaveBeenCalledWith(1) + expect(fs.rename).toHaveBeenCalledWith(expect.stringContaining("safeWriteText_"), targetPath) + }) + + it("fsyncs the parent directory after the commit rename on POSIX", async () => { + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + // temp fd=1 then parent-dir fd=2 - distinct fds prove the ordering + vi.mocked(fsSync.openSync).mockReturnValueOnce(1).mockReturnValue(2) + + await safeWriteText(targetPath, "data", { platform: "linux" }) + + // the directory fsync (fd 2) happens only after the file fsync (fd 1); + // the dir path assertion is path-agnostic (stringContaining) because + // path.dirname renders the same input differently on Windows + expect(fsSync.openSync).toHaveBeenCalledWith(expect.stringContaining("test-dir"), "r") + expect(fsSync.fsyncSync).toHaveBeenNthCalledWith(1, 1) + expect(fsSync.fsyncSync).toHaveBeenNthCalledWith(2, 2) + expect(fsSync.closeSync).toHaveBeenCalledWith(2) + }) + + it("reports a failed parent-directory fsync instead of claiming a durable write", async () => { + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + vi.mocked(fsSync.openSync) + .mockReturnValueOnce(1) + .mockImplementationOnce(() => { + throw new Error("EBADF") + }) + + // The content rename committed, so the caller can still find the data at + // the target; what the write cannot claim is that the directory entry + // reached the disk. Returning success here would claim durability the + // filesystem did not grant. + await expect(safeWriteText(targetPath, "data", { platform: "linux" })).rejects.toThrow( + PostCommitDurabilityError, + ) + + expect(fs.rename).toHaveBeenCalledWith(expect.stringContaining("safeWriteText_"), targetPath) + }) + + it("propagates realpath errors (EACCES and code-less) instead of the fallback path", async () => { + const targetPath = "/tmp/test-dir/target.txt" + const eacces = Object.assign(new Error("EACCES: permission denied"), { code: "EACCES" }) + vi.mocked(fs.realpath).mockRejectedValueOnce(eacces) + await expect(safeWriteText(targetPath, "data", { platform: "linux" })).rejects.toBe(eacces) + expect(fs.rename).not.toHaveBeenCalled() + + const plain = new Error("resolution failed") + vi.mocked(fs.realpath).mockRejectedValueOnce(plain) + await expect(safeWriteText(targetPath, "data", { platform: "linux" })).rejects.toBe(plain) + expect(fs.rename).not.toHaveBeenCalled() + }) + + it("backup:true propagates access errors (EACCES and code-less) instead of skipping the backup", async () => { + const targetPath = "/tmp/test-dir/target.txt" + const eacces = Object.assign(new Error("EACCES"), { code: "EACCES" }) + const plain = new Error("access failed") + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + vi.mocked(fsSync.openSync).mockReturnValue(1) + // each write accesses dirPath then target; only the target access rejects + const rejectTarget = (error: Error) => async (p: unknown) => { + if (typeof p === "string" && p.endsWith("target.txt")) throw error + } + vi.mocked(fs.access) + .mockImplementationOnce(rejectTarget(eacces)) + .mockImplementationOnce(rejectTarget(eacces)) + .mockImplementationOnce(rejectTarget(plain)) + .mockImplementationOnce(rejectTarget(plain)) + + await expect(safeWriteText(targetPath, "data", { backup: true, platform: "linux" })).rejects.toEqual( + expect.objectContaining({ code: "EACCES" }), + ) + await expect(safeWriteText(targetPath, "data", { backup: true, platform: "linux" })).rejects.toThrow( + "access failed", + ) + expect(fs.rename).not.toHaveBeenCalled() + }) + }) + describe("content bytes", () => { + const targetPath = "/tmp/enc-dir/target.txt" + + beforeEach(() => { + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + vi.mocked(fsSync.openSync).mockReturnValue(1) + }) + + it("stages UTF-8 bytes for string content", async () => { + await safeWriteText(targetPath, "héllo", { platform: "linux" }) + expect(fsSync.writeSync).toHaveBeenCalledWith(1, Buffer.from("héllo", "utf8"), 0, 6) + }) + + it("publishes caller-supplied bytes unchanged instead of re-encoding them", async () => { + // The extension host encodes a document with VS Code's own codec, which + // covers the legacy code pages and BOMs Node cannot represent, and hands + // the result over: those bytes must reach the commit rename exactly as + // they were given. + const bytes = Buffer.from([0x00, 0x68, 0x00, 0x69]) + await safeWriteText(targetPath, bytes, { platform: "linux" }) + expect(fsSync.writeSync).toHaveBeenCalledWith(1, bytes, 0, 4) + }) + }) + it("a no-replace commit links the staged file into place when the target is absent", async () => { + // Isolate the commit-phase counters from any async cleanup a previous + // test left in flight. + vi.mocked(fs.rename).mockClear() + vi.mocked(fs.unlink).mockClear() + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + + await safeWriteText(targetPath, "new data", { failIfExist: true, platform: "linux" }) + + // link(2) is the only atomic no-replace publish: a rename would displace a + // target that appeared after the caller's absence check. + expect(fs.link).toHaveBeenCalledWith(expect.stringContaining("safeWriteText"), targetPath) + expect(fs.rename).not.toHaveBeenCalled() + // The staged copy is dropped once the name points at it. + expect( + vi.mocked(fs.unlink).mock.calls.some(function (call) { + return String(call[0]).includes("safeWriteText") + }), + ).toBe(true) + }) + + it("a no-replace commit refuses a target that appeared after the caller checked", async () => { + // Isolate the commit-phase counters from any async cleanup a previous + // test left in flight. + vi.mocked(fs.rename).mockClear() + vi.mocked(fs.unlink).mockClear() + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + vi.mocked(fs.link).mockRejectedValue(Object.assign(new Error("EEXIST"), { code: "EEXIST" })) + // The failure path still cleans up its staging file and directory; keep those + // promises real so the cleanup does not mask the rejection under test. + vi.mocked(fs.unlink).mockResolvedValue(undefined) + vi.mocked(fs.rmdir).mockResolvedValue(undefined) + + const error = await safeWriteText(targetPath, "new data", { + failIfExist: true, + platform: "linux", + }).catch((caught: unknown) => caught) + + expect(error).toBeInstanceOf(TargetExistsError) + expect((error as TargetExistsError).targetPath).toBe(targetPath) + // Nothing replaced the newer file, and the staged copy is not left behind. + expect(fs.rename).not.toHaveBeenCalled() + expect( + vi.mocked(fs.unlink).mock.calls.some(function (call) { + return String(call[0]).includes("safeWriteText") + }), + ).toBe(true) + }) + + it("resolves an absent target through a symlinked ancestor to the canonical path", async () => { + // The guard pins the publish to the canonical nearest-ancestor path. An absent + // target has to resolve to that same path, or a create through a symlinked + // ancestor aborts with TargetMovedError although nothing moved. + const linkDir = path.resolve("/tmp/link-dir") + const canonicalDir = path.resolve("/real/dir") + const canonical = path.join(canonicalDir, "target.txt") + vi.mocked(fs.realpath).mockImplementation(async (p: unknown) => { + if (String(p) === path.join(linkDir, "target.txt")) { + throw Object.assign(new Error("ENOENT"), { code: "ENOENT" }) + } + if (String(p) === linkDir) return canonicalDir + return String(p) + }) + vi.mocked(fs.lstat).mockRejectedValue(Object.assign(new Error("ENOENT"), { code: "ENOENT" })) + + await safeWriteText(path.join(linkDir, "target.txt"), "new data", { + expectedResolvedPath: canonical, + platform: "linux", + }) + + expect(fs.rename).toHaveBeenCalledWith(expect.stringContaining("safeWriteText"), canonical) + }) + + it("falls back to an exclusive copy when the filesystem has no hard links", async () => { + // FAT32/exFAT and some SMB mounts reject link(2); the create must still work, and + // COPYFILE_EXCL keeps the no-replace verdict identical. + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + vi.mocked(fs.link).mockRejectedValue(Object.assign(new Error("ENOTSUP"), { code: "ENOTSUP" })) + + await safeWriteText(targetPath, "new data", { failIfExist: true, platform: "linux" }) + + expect(fs.copyFile).toHaveBeenCalledWith( + expect.stringContaining("safeWriteText"), + targetPath, + fsSync.constants.COPYFILE_EXCL, + ) + expect(fs.rename).not.toHaveBeenCalled() + }) + + it("refuses the write when the exclusive copy finds an existing target", async () => { + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + vi.mocked(fs.link).mockRejectedValue(Object.assign(new Error("EPERM"), { code: "EPERM" })) + vi.mocked(fs.copyFile).mockRejectedValue(Object.assign(new Error("EEXIST"), { code: "EEXIST" })) + + await expect( + safeWriteText(targetPath, "new data", { failIfExist: true, platform: "linux" }), + ).rejects.toBeInstanceOf(TargetExistsError) + }) + + it("still reports success when the staged copy cannot be unlinked after the link", async () => { + // An antivirus handle on Windows can make unlink fail with EBUSY after link(2) + // published the name. The content is readable at the target, so the write must + // not be reported as a failure the model then retries into an 'already exists'. + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + vi.mocked(fs.unlink).mockRejectedValue(Object.assign(new Error("EBUSY"), { code: "EBUSY" })) + + await expect( + safeWriteText(targetPath, "new data", { failIfExist: true, platform: "linux" }), + ).resolves.toBeUndefined() + expect(fs.link).toHaveBeenCalledWith(expect.stringContaining("safeWriteText"), targetPath) + }) + + it("refuses to publish when the path no longer resolves to the authorized target", async () => { + // Isolate the commit-phase counters from any async cleanup a previous test left + // in flight. + vi.mocked(fs.rename).mockClear() + vi.mocked(fs.link).mockClear() + const authorized = "/tmp/test-dir/target.txt" + // The caller authorized this path while it was a real file in the workspace; by the + // time the publish resolves it, a local process has swapped in a link to somewhere + // else. The decision was never made about that other file, so nothing is published. + vi.mocked(fs.realpath).mockResolvedValue("/outside/the-victim.txt") + + const error = await safeWriteText(authorized, "new data", { + expectedResolvedPath: authorized, + platform: "linux", + }).catch((caught: unknown) => caught) + + expect(error).toBeInstanceOf(TargetMovedError) + const moved = error as TargetMovedError + expect(moved.authorizedPath).toBe(authorized) + expect(moved.resolvedPath).toBe("/outside/the-victim.txt") + expect(moved.message).toContain("/outside/the-victim.txt") + expect(fs.rename).not.toHaveBeenCalled() + expect(fs.link).not.toHaveBeenCalled() + // Nothing was staged either: the check runs before the staging directory is made. + expect(fs.mkdir).not.toHaveBeenCalled() + }) + + it("refuses to publish when an authorized parent directory was replaced after the check", async () => { + // expectedResolvedPath pins the NAME being published, so it cannot notice the + // directory the name lives in being swapped for another one (a link to outside the + // workspace looks exactly like this). The recorded ancestor identities are what + // catch it, and the commit is aborted before anything is moved into place. + const dir = path.resolve("/tmp/test-dir") + const targetPath = path.join(dir, "target.txt") + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + vi.mocked(fs.rename).mockClear() + vi.mocked(fs.link).mockClear() + vi.mocked(fs.stat).mockResolvedValue(_dirIdentity(999n)) // was 100n when authorized + + const error = await safeWriteText(targetPath, "new data", { + expectedResolvedPath: targetPath, + expectedAncestorIdentities: [{ dir, dev: 1n, ino: 100n }], + platform: "linux", + }).catch((caught: unknown) => caught) + + expect(error).toBeInstanceOf(AncestorReplacedError) + expect((error as AncestorReplacedError).directory).toBe(dir) + expect((error as AncestorReplacedError).message).toContain("no longer the directory that was authorized") + expect(fs.rename).not.toHaveBeenCalled() + expect(fs.link).not.toHaveBeenCalled() + // The staged copy is cleaned up rather than left beside the target. + expect( + vi.mocked(fs.unlink).mock.calls.some((call) => String(call[0]).includes("safeWriteText")), + ).toBe(true) + }) + + it("publishes when the recorded ancestor identities are unchanged", async () => { + // The pin must not turn every guarded write into a false rejection: an unchanged + // directory chain publishes normally. + const dir = path.resolve("/tmp/test-dir") + const targetPath = path.join(dir, "target.txt") + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + vi.mocked(fs.stat).mockResolvedValue(_dirIdentity(100n)) + + await safeWriteText(targetPath, "new data", { + expectedResolvedPath: targetPath, + expectedAncestorIdentities: [{ dir, dev: 1n, ino: 100n }], + platform: "linux", + }) + + expect(fs.rename).toHaveBeenCalledWith(expect.stringContaining("safeWriteText"), targetPath) + }) + + it("refuses the publish when an authorized ancestor disappears before the commit", async () => { + const dir = path.resolve("/tmp/test-dir") + const targetPath = path.join(dir, "target.txt") + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + vi.mocked(fs.stat).mockRejectedValue(Object.assign(new Error("ENOENT"), { code: "ENOENT" })) + + const error = await safeWriteText(targetPath, "new data", { + expectedResolvedPath: targetPath, + expectedAncestorIdentities: [{ dir, dev: 1n, ino: 100n }], + platform: "linux", + }).catch((caught: unknown) => caught) + + expect(error).toBeInstanceOf(AncestorReplacedError) + expect((error as AncestorReplacedError).message).toContain("no longer exists") + expect(fs.rename).not.toHaveBeenCalled() + expect(fs.link).not.toHaveBeenCalled() + }) +}) + +// ── Test 12: lock key, staging path, and post-commit durability ───────────── + +describe("resolveLockKey", () => { + beforeEach(() => mockDefaults()) + + it("canonicalizes the parent directory, not just the file", async () => { + vi.mocked(fs.realpath).mockImplementation(async (target) => { + const key = String(target) + if (key === "/tmp/linkdir/file.json") return "/real/dir/file.json" + if (key === "/real/dir") return "/real/dir" + return key + }) + + // The key is the canonical directory plus the basename, so a symlinked + // ancestor and its referent share one lock. + await expect(resolveLockKey("/tmp/linkdir/file.json")).resolves.toBe(path.join("/real/dir", "file.json")) + }) + + it("computes a key for a dangling link, which resolvePublishTarget refuses", async () => { + const enoent = Object.assign(new Error("ENOENT: no such file or directory"), { code: "ENOENT" }) + vi.mocked(fs.realpath).mockRejectedValue(enoent) + vi.mocked(fs.lstat).mockResolvedValue(_fileStats(true)) + // The walk ends when readlink throws, because a plain file is not a link. + // Answering every call with the same value would let a walk that never + // stopped return the same key, so the mock has to distinguish the link from + // the referent and the test has to check that the walk stopped. + const notALink = Object.assign(new Error("EINVAL: not a link"), { code: "EINVAL" }) + vi.mocked(fs.readlink).mockImplementation(async (target) => { + if (String(target) === "/tmp/linkdir/file.json") return "referent.json" + throw notALink + }) + + // Mid-commit a peer writer renames the referent away and back, so the key + // must still be computable while the link dangles. + await expect(resolveLockKey("/tmp/linkdir/file.json")).resolves.toBe( + path.resolve(path.join("/tmp/linkdir", "referent.json")), + ) + // Two calls means the walk stopped at the referent: the link, then one more + // on the referent that reports it is not a link. A walk that never stopped + // would run the full 8 steps. + expect(fs.readlink).toHaveBeenCalledTimes(2) + }) + + it("terminates on a two-link cycle instead of walking forever", async () => { + const enoent = Object.assign(new Error("ENOENT: no such file or directory"), { code: "ENOENT" }) + vi.mocked(fs.realpath).mockRejectedValue(enoent) + vi.mocked(fs.lstat).mockResolvedValue(_fileStats(true)) + // Every readlink answers with the same link, so an unbounded walk would + // never end; the bounded walk returns the key it actually reached. + vi.mocked(fs.readlink).mockImplementation(async () => "a.json") + + await expect(resolveLockKey("/tmp/linkdir/a.json")).resolves.toBe( + path.resolve(path.join("/tmp/linkdir", "a.json")), + ) + expect(fs.readlink).toHaveBeenCalledTimes(8) + }) +}) + +describe("caller-supplied staging path", () => { + beforeEach(() => mockDefaults()) + + it("rejects a staging file outside the target's directory before writing anything", async () => { + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + + // A rename across filesystems fails with EXDEV, and a path elsewhere lets + // a caller publish an unrelated file onto the target. + await expect( + safeWriteText(targetPath, "data", { tempPath: "/tmp/other-dir/x.tmp", platform: "linux" }), + ).rejects.toThrow(StagingPathError) + expect(fsSync.openSync).not.toHaveBeenCalled() + expect(fs.rename).not.toHaveBeenCalled() + }) + + it("rejects a staging path that is a symlink", async () => { + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + vi.mocked(fs.lstat).mockResolvedValue(_fileStats(true)) + + // Renaming a link over the target publishes whatever the link points at. + await expect( + safeWriteText(targetPath, "data", { tempPath: "/tmp/test-dir/x.tmp", platform: "linux" }), + ).rejects.toThrow(StagingPathError) + expect(fsSync.openSync).not.toHaveBeenCalled() + expect(fs.rename).not.toHaveBeenCalled() + }) +}) + +describe("cleanup before a rollback failure is reported", () => { + beforeEach(() => mockDefaults()) + + it("releases the staged file, its copy and its own staging directory before throwing", async () => { + const targetPath = "/tmp/test-dir/target.txt" + vi.mocked(fs.realpath).mockResolvedValue(targetPath) + vi.mocked(fsSync.openSync).mockReturnValue(1) + // The commit rename is the only rename in this flow and it fails. + vi.mocked(fs.rename).mockRejectedValue(new Error("ENOSPC")) + + await expect(safeWriteText(targetPath, "data", { backup: true, platform: "linux" })).rejects.toThrow("ENOSPC") + + // The staging file and this write's own directory must not leak, and neither may + // the backup copy: the target still holds the pre-write content on disk. + expect(fs.unlink).toHaveBeenCalledWith(expect.stringContaining("safeWriteText_")) + expect(fs.unlink).toHaveBeenCalledWith(expect.stringContaining("safeWriteText.bak_")) + const stagingDirs = vi.mocked(fsSync.mkdirSync).mock.calls.map((call) => String(call[0])) + expect(stagingDirs.length).toBe(1) + expect(fs.rmdir).toHaveBeenCalledWith(stagingDirs[0]) + + const failingRenameOrder = vi.mocked(fs.rename).mock.invocationCallOrder[0] + const unlinkOrder = vi.mocked(fs.unlink).mock.invocationCallOrder[0] + const rmdirOrder = vi.mocked(fs.rmdir).mock.invocationCallOrder[0] + expect(unlinkOrder).toBeGreaterThan(failingRenameOrder) + expect(rmdirOrder).toBeGreaterThan(failingRenameOrder) + }) +}) + +describe("resolvePublishTarget", () => { + beforeEach(() => mockDefaults()) + + it("propagates an lstat failure that is not ENOENT instead of falling back to the link path", async () => { + const targetPath = "/tmp/test-dir/target.txt" + const enoent = Object.assign(new Error("ENOENT: no such file or directory"), { code: "ENOENT" }) + const eacces = Object.assign(new Error("EACCES: permission denied"), { code: "EACCES" }) + vi.mocked(fs.realpath).mockRejectedValue(enoent) + vi.mocked(fs.lstat).mockRejectedValue(eacces) + + // A failed lstat says nothing about whether the path is a link, so the + // fallback would publish through a link we were not allowed to inspect. + await expect(safeWriteText(targetPath, "data", { platform: "linux" })).rejects.toBe(eacces) + expect(fs.rename).not.toHaveBeenCalled() + }) + + it("still falls back to the given path when lstat also reports the path as absent", async () => { + const targetPath = "/tmp/test-dir/target.txt" + const enoent = Object.assign(new Error("ENOENT: no such file or directory"), { code: "ENOENT" }) + vi.mocked(fs.realpath).mockRejectedValue(enoent) + vi.mocked(fs.lstat).mockRejectedValue(enoent) + vi.mocked(fsSync.openSync).mockReturnValue(1) + + await safeWriteText(targetPath, "data", { platform: "linux" }) + + // The fallback is the resolved path, not the string that was handed in. + expect(fs.rename).toHaveBeenCalledWith(expect.stringContaining("safeWriteText_"), path.resolve(targetPath)) + }) +}) + + + +describe("resolveLockKey when the parent directory does not exist yet", () => { + beforeEach(() => mockDefaults()) + + it("canonicalizes through the nearest existing ancestor instead of the literal parent", async () => { + // Two writers must take ONE lock: the one whose parent directory is already there, + // and the one racing to create it. Resolving only the immediate parent and falling + // back to its literal spelling on ENOENT gave them different keys whenever an + // ancestor was a symlink or a Windows short name, so a read-modify-write under the + // advisory lock lost one side. + const aliasDir = path.resolve("/tmp/alias-parent") + const canonicalDir = path.resolve("/tmp/real-parent") + const nested = path.join(aliasDir, "nested") + const target = path.join(nested, "history_item.json") + vi.mocked(fs.lstat).mockResolvedValue(_fileStats(false)) + vi.mocked(fs.realpath).mockImplementation(async (p) => { + const s = String(p) + if (s === target || s === nested) { + throw Object.assign(new Error("ENOENT: no such file or directory"), { code: "ENOENT" }) + } + if (s === aliasDir) { + return canonicalDir + } + return s + }) + + expect(await resolveLockKey(target)).toBe(path.join(canonicalDir, "nested", "history_item.json")) + }) + + it("propagates a realpath failure that is not ENOENT instead of guessing a key", async () => { + // A realpath that fails for another reason says nothing about the canonical form; + // returning a literal key would silently put this writer on a different lock. + const target = path.join(path.resolve("/tmp/test-dir"), "history_item.json") + vi.mocked(fs.lstat).mockResolvedValue(_fileStats(false)) + // Not a link: the walk must reach the canonicalization step, which is where the + // non-ENOENT failure has to surface. + vi.mocked(fs.readlink).mockRejectedValue(Object.assign(new Error("ENOENT: no such file or directory"), { code: "ENOENT" })) + vi.mocked(fs.realpath).mockImplementation(async (p) => { + if (String(p) === target) return target + throw Object.assign(new Error("EACCES: permission denied"), { code: "EACCES" }) + }) + + await expect(resolveLockKey(target)).rejects.toThrow("EACCES") + }) +}) diff --git a/src/services/file-safety/safeWriteText.ts b/src/services/file-safety/safeWriteText.ts new file mode 100644 index 0000000000..b9ae36c339 --- /dev/null +++ b/src/services/file-safety/safeWriteText.ts @@ -0,0 +1,761 @@ +import * as fs from "fs/promises" +import * as fsSync from "fs" +import * as path from "path" +import { execFile } from "child_process" + +export interface SafeWriteTextOptions { + /** + * When true, preserve the old-file semantics: rename target -> backup first, + * after commit rename delete the backup; on failure roll the backup back to + * the target path. When false (default) the atomic rename simply replaces + * the target -- crash-safe window is zero. + */ + backup?: boolean + + /** + * Platform override for testing. When omitted the real process.platform + * value is used. Set to "win32" or "linux" / "darwin" from tests so that + * both branches are reachable without needing a real Windows runner. + */ + platform?: string + + /** + * Custom execFile runner for testing (e.g. vi.fn). When omitted the real + * child_process.execFile is used. + */ + execFileRunner?: typeof execFile + + /** + * Pre-written temp path to use for the commit phase. When provided, + * safeWriteText skips creating its own staging file and uses this path + * instead (it still fsyncs before rename). Useful when a caller has + * already written data to a temp file via a custom stream. + */ + tempPath?: string + + /** + * Commit only if the target name does NOT exist at commit time. + * rename(2) has no no-replace form - it silently displaces a target that another + * writer created after the caller's absence check - so the commit is done with + * link(2) instead, which fails EEXIST for an existing name (and does not follow a + * symlink placed at that name). A conditional create therefore cannot overwrite a + * file it never saw. + */ + failIfExist?: boolean + + /** + * The publish target the caller already authorized. + * A caller that checks workspace containment and then calls this primitive resolves + * the path twice: once for its own decision and once here. If a link is swapped in + * between the two, the decision was about a different file than the one published. + * Passing the authorized value makes that drift fatal instead of silent. + */ + expectedResolvedPath?: string + + /** + * The directories the caller walked when it authorized this target, with the + * (dev, ino) identity each had at that moment. + * + * expectedResolvedPath pins the NAME this write publishes; it cannot see a parent + * directory being replaced by a link between the caller's containment check and the + * commit. Re-checking the ancestor identities immediately before the commit makes a + * swapped parent fatal too: the publish then aborts instead of writing through the new + * link. Node has no descriptor-relative rename, so a swap that lands after this check + * and before the rename is not eliminable here - it narrows the window to the commit + * itself rather than the whole guard. + */ + expectedAncestorIdentities?: DirectoryIdentity[] +} + +/** One directory's on-disk identity, read with bigint stats so NTFS 64-bit values survive. */ +export type DirectoryIdentity = { + dir: string + dev: bigint + ino: bigint +} + +/** + * The backup copy could not be created AND the partial copy could not be removed. + * The write failed either way, but the leftover is a copy of the previous content that + * is still on disk: its path travels on the error so the caller can remove it, instead + * of the cleanup silently discarding the only reference to it. + */ +export class OrphanedBackupError extends Error { + readonly orphanedBackupPath: string + readonly originalError: unknown + readonly cleanupError: unknown + constructor(backupPath: string, targetPath: string, cause: unknown, cleanupError: unknown) { + super(_orphanedBackupMessage(targetPath, backupPath, cause, cleanupError), { cause }) + this.name = "OrphanedBackupError" + this.orphanedBackupPath = backupPath + this.originalError = cause + this.cleanupError = cleanupError + } +} + +function _orphanedBackupMessage( + targetPath: string, + backupPath: string, + cause: unknown, + cleanupError: unknown, +): string { + const reason = (error: unknown): string => (error instanceof Error ? error.message : String(error)) + return ( + `safeWriteText: could not create the backup of ${targetPath} (${reason(cause)}), and the ` + + `partial copy at ${backupPath} could not be removed (${reason(cleanupError)}). The copy is ` + + `still on disk and must be deleted.` + ) +} + +/** + * A caller-supplied staging path that is not a file this write may publish: it + * sits outside the target's directory (so the commit rename would cross + * filesystems) or is not a regular file. Rejecting it before any write keeps the + * target from being replaced by whatever the path points at. + */ +export class StagingPathError extends Error { + readonly stagingPath: string + + constructor(message: string, stagingPath: string) { + super(message) + this.name = "StagingPathError" + this.stagingPath = stagingPath + } +} + +/** + * The commit rename succeeded but the parent-directory fsync did not, so the + * directory entry is not known to be durable. The content is at the target; the + * caller cannot assume it survives a crash. Reported as its own error so a + * successful return never claims durability the filesystem did not grant. + */ +export class PostCommitDurabilityError extends Error { + readonly targetPath: string + + constructor(targetPath: string, cause: unknown) { + super( + "The rename committed but the parent directory could not be fsynced -- the content is at the target path reported on this error, and the directory entry may not be durable.", + { cause }, + ) + this.name = "PostCommitDurabilityError" + this.targetPath = targetPath + } +} + +/** + * A conditional create (failIfExist) found a target at commit time. The write is + * refused without touching it: whatever is at the path was created by someone else + * and stays exactly as it is. + */ +export class TargetExistsError extends Error { + readonly targetPath: string + constructor(targetPath: string) { + super(`A file already exists at ${targetPath} -- the no-replace commit refused it.`) + this.name = "TargetExistsError" + this.targetPath = targetPath + } +} + +/** + * The path resolved to something other than the target the caller authorized. + * Nothing is staged or published: a link swapped in after the caller's containment + * check would otherwise send the write to a file that check never covered. + */ +export class TargetMovedError extends Error { + readonly authorizedPath: string + readonly resolvedPath: string + constructor(authorizedPath: string, resolvedPath: string) { + super( + `The write was authorized for ${authorizedPath}, but that path now resolves to ${resolvedPath} -- nothing was published.`, + ) + this.name = "TargetMovedError" + this.authorizedPath = authorizedPath + this.resolvedPath = resolvedPath + } +} + +/** + * A directory the caller walked on its way to the authorized target is no longer the + * directory it was: it was removed, replaced, or turned into a link to somewhere else. + * Publishing through it would act on a decision that was never made about the file now + * reachable there, so the commit is aborted. + */ +export class AncestorReplacedError extends Error { + readonly directory: string + constructor(directory: string, reason: string) { + super(`A directory on the authorized path (${directory}) ${reason} -- nothing was published.`) + this.name = "AncestorReplacedError" + this.directory = directory + } +} +// -- helpers --------------------------------------------------------------- + +/** Generate a unique temp file name in the given directory. */ +function _tempName(dir: string, prefix: string): string { + return path.join(dir, "." + prefix + "_" + Date.now() + "_" + Math.random().toString(36).substring(2) + ".tmp") +} + +/** Create a private per-write staging sub-directory inside *dir*. The name is + * unique per write, so concurrent writes never collide on their temp names and + * never remove a staging directory another write is still using: with one shared + * name, one write's best-effort rmdir could delete the directory another write + * had just created but not yet opened, failing its openSync with ENOENT. */ +function _stagingDir(dir: string): string { + const sd = path.join(dir, ".file-safety-staging_" + Date.now() + "_" + Math.random().toString(36).substring(2)) + // mode:0o700 protects a freshly created staging dir; the best-effort chmod + // repairs a pre-existing one (mkdirSync with recursive:true never chmods an + // existing directory), so staged temp files are never group/world readable. + fsSync.mkdirSync(sd, { recursive: true, mode: 0o700 }) + try { + fsSync.chmodSync(sd, 0o700) + } catch { + // best-effort: chmod denied or unavailable; a fresh dir was still + // created with the requested mode + } + return sd +} + +function _fsyncFile(fd: number): void { + fsSync.fsyncSync(fd) +} + +/** Save the DACL of *srcPath* to a dump file on Windows. + * Returns true when the dump was written successfully; false otherwise. + * Never throws — callers treat failure as "skip DACL handling". */ +async function _saveDaclWindows(srcPath: string, dumpPath: string, execFileRunner?: typeof execFile): Promise { + const runner = execFileRunner ?? execFile + try { + await new Promise((resolve, reject) => { + runner("icacls", [srcPath, "/save", dumpPath, "/T"], { windowsHide: true }, (err) => + err ? reject(err) : resolve(), + ) + }) + return true + } catch { + return false + } +} + +/** Restore a DACL dump onto *dirPath* on Windows. + * Best-effort: content is already committed, so failure is non-fatal. */ +async function _restoreDaclWindows(dirPath: string, dumpPath: string, execFileRunner?: typeof execFile): Promise { + const runner = execFileRunner ?? execFile + try { + await new Promise((resolve, reject) => { + runner("icacls", [dirPath, "/restore", dumpPath], { windowsHide: true }, (err) => + err ? reject(err) : resolve(), + ) + }) + } catch { + // best-effort; content already committed + } +} + +// -- public API ------------------------------------------------------------ + +/** + * Resolve the publish target: the symlink referent when the given path is an + * existing symlink, the path itself otherwise. Only ENOENT (target absent yet) + * may fall back to the given path; any other resolution error (EACCES, EIO, ...) + * propagates so a broken or unreadable symlink is never written through its + * link path. Callers that stage a temp file themselves must stage it beside + * the resolved path: the commit is a rename onto the referent, and a rename + * across filesystems fails with EXDEV. + */ +export async function resolvePublishTarget(absoluteFilePath: string): Promise { + return fs.realpath(absoluteFilePath).catch(async (error: unknown) => { + if (errorCode(error) !== "ENOENT") throw error + // ENOENT also covers a dangling symlink, which must never be written through. + // Only a lstat that also reports the path as absent may fall back to the + // given path; a real lstat failure (EACCES, EIO) says nothing about whether + // the path is a link, so falling back would write through a link we were + // simply not allowed to inspect. + const linkStat = await fs.lstat(absoluteFilePath).catch((lstatError: unknown) => { + if (errorCode(lstatError) === "ENOENT") return undefined + throw lstatError + }) + if (linkStat?.isSymbolicLink()) throw error + return await canonicalizeNearestAncestor(absoluteFilePath) + }) +} +/** + * Distinguish "the target does not exist" from a real I/O failure (EACCES, + * EIO, ...). The mode-preservation path may only fall back to the fresh-file + * default on ENOENT; any other failure is propagated, otherwise a restrictive + * target (0o600) would be published with the default 0o644 through the rename. + */ +function errorCode(error: unknown): string | undefined { + return typeof error === "object" && error !== null && "code" in error + ? String((error as { code: unknown }).code) + : undefined +} + +/** + * Canonicalize the parent directory and re-join the basename. fs.realpath + * canonicalizes every component, including a symlinked ancestor directory or a + * Windows 8.3 short name, so a lock key must be canonical even when the file + * itself is not there yet -- otherwise the key for one file depends on whether + * the file exists when the key is computed, and two writers take two locks. + */ + +async function canonicalDirKey(absoluteFilePath: string): Promise { + const dirPath = path.dirname(absoluteFilePath) + // Walk up to the nearest ancestor that EXISTS, canonicalize that, and re-join the + // components that are not there yet. Falling back to the unresolved spelling of the + // whole parent - what a single realpath(...).catch(() => dirPath) used to do - makes + // the key depend on whether the directory happens to exist: a writer whose parent is + // already there canonicalizes through a symlinked ancestor (or a short name) while a + // writer racing to create the same directory gets the literal spelling, so the two + // take different locks for one file and a read-modify-write loses one side. + // A realpath failure that is not "not there yet" says nothing about the canonical + // form, so it is propagated rather than papered over with a key that may be wrong. + let cursor = dirPath + const missing: string[] = [] + for (;;) { + const canonical = await fs.realpath(cursor).catch((error: unknown) => { + if (errorCode(error) === "ENOENT") return undefined + throw error + }) + if (canonical !== undefined) { + return path.join(canonical, ...missing.reverse(), path.basename(absoluteFilePath)) + } + missing.push(path.basename(cursor)) + const parent = path.dirname(cursor) + if (parent === cursor) { + // Every component up to the root is missing: there is nothing to canonicalize + // against, and the literal path is the only key left. + return path.join(dirPath, path.basename(absoluteFilePath)) + } + cursor = parent + } +} + +/** + * Canonicalize the nearest EXISTING ancestor and re-append the missing components. + * The guard hands back a pin produced exactly this way (guardedWrite#realpathNearest), + * so an absent target has to resolve identically here: a lexical fallback differs from + * that pin whenever an ancestor is a symlink, and the create would then abort with + * TargetMovedError even though nothing moved. + */ +async function canonicalizeNearestAncestor(absoluteFilePath: string): Promise { + const missing: string[] = [] + let cursor = absoluteFilePath + for (;;) { + try { + const realPath = await fs.realpath(cursor) + return missing.length > 0 ? path.join(realPath, ...missing.reverse()) : realPath + } catch (error: unknown) { + const code = errorCode(error) + if (code !== "ENOENT" && code !== "ENOTDIR") return absoluteFilePath + const parent = path.dirname(cursor) + if (parent === cursor) return absoluteFilePath + missing.push(path.basename(cursor)) + cursor = parent + } + } +} + +/** + * Lock key for a publish target: the symlink referent when the path is an + * existing symlink, the path itself otherwise. Unlike resolvePublishTarget this + * tolerates a dangling link, because the lock key has to be computable while a + * peer writer is mid-commit (backup mode renames the referent away and back). + * The walk is bounded so a two-link cycle terminates, and every key it returns is + * canonicalized through canonicalDirKey. + */ +export async function resolveLockKey(absoluteFilePath: string): Promise { + try { + return await canonicalDirKey(await resolvePublishTarget(absoluteFilePath)) + } catch { + // A real readlink throws for anything that is not a link, so a normal chain + // ends the walk. Two links that point at each other never would, so the + // walk is bounded and callers use the key they actually reached. + let key = absoluteFilePath + for (let depth = 0; depth < 8; depth++) { + const target = await fs.readlink(key).catch(() => undefined) + if (target === undefined) return await canonicalDirKey(key) + key = await canonicalDirKey(path.resolve(path.dirname(key), target)) + } + return await canonicalDirKey(key) + } +} + +export async function safeWriteText( + filePath: string, + content: string | Uint8Array, + options?: SafeWriteTextOptions, +): Promise { + const absoluteFilePath = path.resolve(filePath) + + // Resolve the symlink referent (see resolvePublishTarget). + const targetPath = await resolvePublishTarget(absoluteFilePath) + + // The caller authorized a specific resolved path; publishing at a different one + // would act on a decision that was never made about this file. + if (options?.expectedResolvedPath && path.resolve(options.expectedResolvedPath) !== targetPath) { + throw new TargetMovedError(options.expectedResolvedPath, targetPath) + } + + const dirPath = path.dirname(targetPath) + + // Ensure parent directory exists (mirrors safeWriteJson behaviour). + await fs.mkdir(dirPath, { recursive: true }) + await fs.access(dirPath) + + // Create the staging directory only when we generate the temp file there; + // callers supplying their own tempPath (e.g. safeWriteJson) must not be left + // with an empty .file-safety-staging directory behind. Track the directory this + // write created so its cleanup removes its own directory, not a shared one. + let stagingDir: string | null = null + let tempPath: string + if (options?.tempPath) { + // A caller-supplied staging file is only safe when it is the file this + // write is staging, not an arbitrary path. Two properties are checked: + // it must sit beside the resolved target (a rename across filesystems + // fails with EXDEV, and a path elsewhere lets a caller publish an + // unrelated file onto the target), and it must be a regular file rather + // than a link — renaming a link over the target publishes whatever the + // link points at, which is the same trust problem as writing through a + // dangling symlink in resolvePublishTarget. + const supplied = path.resolve(options.tempPath) + if (path.dirname(supplied) !== path.resolve(dirPath)) { + throw new StagingPathError( + `Staging file must sit in the target's directory (${dirPath}), got ${supplied}`, + supplied, + ) + } + const stagingStat = await fs.lstat(supplied) + if (stagingStat.isSymbolicLink() || !stagingStat.isFile()) { + throw new StagingPathError( + `Staging file must be a regular file, not ${stagingStat.isSymbolicLink() ? "a symlink" : "another file type"}`, + supplied, + ) + } + // The caller's own path is used as given; only the check is canonical. + tempPath = options.tempPath + } else { + stagingDir = _stagingDir(dirPath) + tempPath = _tempName(stagingDir, "safeWriteText") + } + + let backupPath: string | null = null + let releaseBackupOnSuccess = false + // Non-null only when the win32 step-2 block saved a successful DACL dump: + // it gates the step-5 restore and is tracked for the cleanup unlinks. + let daclDumpPath: string | null = null + + try { + // -- Step 1: write content to staging temp file ------------------- + if (!options?.tempPath) { + // Preserve the existing target's permissions: the staging file must + // not be published wider than the file it replaces (a 0o600 target + // must not become 0o644 through the atomic rename). + // Encode before opening the staging file: an encoding Node cannot + // represent must not leave a half-written temp file behind. + // A string is encoded as UTF-8; bytes handed in by the caller (the + // extension host encodes a document with VS Code's own codec, which + // covers the legacy code pages Node cannot represent) are published + // unchanged. + const buffer = Buffer.from(content) + let targetMode = 0o644 // default for a fresh target + let targetExists = false + try { + targetMode = fsSync.statSync(targetPath).mode & 0o777 + targetExists = true + } catch (error: unknown) { + if (errorCode(error) !== "ENOENT") throw error + // target does not exist yet - keep the default + } + // openSync's creation mode is narrowed by the process umask, so an + // existing 0o664 target would be published as 0o644 through the + // rename. Apply the existing target's exact mode on the fd, as the + // caller-staged branch does; a fresh target keeps the default mode. + const fd = fsSync.openSync(tempPath, "w", targetMode) + try { + if (targetExists) { + fsSync.fchmodSync(fd, targetMode) + } + // Loop until every byte is written: writeSync can report a short + // (partial) write, and publishing a truncated staging file would + // commit corrupt content. + let offset = 0 + while (offset < buffer.length) { + offset += fsSync.writeSync(fd, buffer, offset, buffer.length - offset) + } + _fsyncFile(fd) + } finally { + fsSync.closeSync(fd) + } + } else { + // Preserve the existing target's mode (CWE-732): the caller-staged + // temp carries its own creation mode, and publishing it as-is would + // widen a restrictive target (e.g. 0o600 -> 0o644) through rename. + // The mode is applied with fchmodSync on the open fd (AFTER openSync): + // chmodSync on the path before the open would make a read-only target + // (0o400/0o444) fail openSync(tempPath, "r+") with EACCES. + let targetMode: number | null = null + try { + targetMode = fsSync.statSync(targetPath).mode & 0o777 + } catch (error: unknown) { + if (errorCode(error) !== "ENOENT") throw error + // target does not exist yet - keep the temp's default mode + } + const fd = fsSync.openSync(tempPath, "r+") + try { + if (targetMode !== null) { + fsSync.fchmodSync(fd, targetMode) + } + _fsyncFile(fd) + } finally { + fsSync.closeSync(fd) + } + } + + // -- Step 2 (win32): save DACL BEFORE backup rename --------------- + const platform = options?.platform ?? process.platform + if (platform === "win32") { + try { + await fs.access(targetPath) // target exists? + const dumpPath = _tempName(dirPath, "safeWriteText.acl") + const saved = await _saveDaclWindows(targetPath, dumpPath, options?.execFileRunner) + if (saved) { + // Only a successfully saved dump may be restored onto the + // committed file (step 5). + daclDumpPath = dumpPath + } else { + // A failed icacls may have left a partial dump behind; + // remove it now (best-effort) so no partial dump survives and + // no later step can restore from it. + await fs.unlink(dumpPath).catch(() => {}) + } + } catch { + // target does not exist or access failed — no DACL handling + daclDumpPath = null + } + } + + try { + // -- Step 2b: re-validate the authorized ancestry before committing -- + // The caller decided containment by walking this directory chain. A parent + // swapped for a link to outside that chain would send the commit somewhere the + // caller never authorized, even though expectedResolvedPath still matches (the + // name is unchanged). Compare each recorded identity now, before anything is + // moved into place. + if (options?.expectedAncestorIdentities) { + for (const expected of options.expectedAncestorIdentities) { + const current = await fs.stat(expected.dir, { bigint: true }).catch((error: unknown) => { + if (errorCode(error) === "ENOENT") { + throw new AncestorReplacedError(expected.dir, "no longer exists") + } + throw error + }) + if (current.dev !== expected.dev || current.ino !== expected.ino) { + throw new AncestorReplacedError(expected.dir, "is no longer the directory that was authorized") + } + } + } + + // -- Step 3 (backup:true): durable copy target -> backup ---- + if (options?.backup) { + try { + await fs.access(targetPath) + backupPath = _tempName(dirPath, "safeWriteText.bak") + // Copy, never move. Renaming the target away leaves the canonical path absent for + // the whole commit window: readers see a missing file, and a concurrent + // writer can create a new target that a later rollback would destroy. A copy + // keeps the target present, so the step 4 rename is the only change to the + // canonical path. The copy is flushed so the retained content survives a crash. + try { + // Create the destination BEFORE any content exists at it, with the mode fixed + // at open time. fs.copyFile picks the destination mode itself (the platform + // creation mask subject to umask on some platforms, the source's mode - or its + // read-only attribute - on others), so letting it create the file would either + // leave a restrictive target's bytes briefly readable to others, or leave the + // copy unwritable so the fsync open below fails with EACCES. open() ignores its + // mode argument for an existing file, so this 0o600 survives the copy on POSIX; + // the chmod afterwards is what clears a copied read-only attribute on Windows + // and keeps a backup of a permissive file private. + const seedFd = fsSync.openSync(backupPath, "wx", 0o600) + // Single close, no retry: on POSIX close(2) can release the descriptor before it + // reports an error (and leaves its state unspecified after EINTR), so a second + // close could release a descriptor some other operation has meanwhile reused. + // The failure propagates; backupPath is already recorded, so the outer cleanup + // removes the seeded file instead of leaving it beside the target. + fsSync.closeSync(seedFd) + await fs.copyFile(targetPath, backupPath) + await fs.chmod(backupPath, 0o600) + // "r+" not "r": fsync on a read-only handle is EPERM on Windows, and the same + // flag the staged temp file uses above. + const backupFd = fsSync.openSync(backupPath, "r+") + try { + _fsyncFile(backupFd) + } finally { + fsSync.closeSync(backupFd) + } + } catch (backupError: unknown) { + // A partial backup must not outlive this attempt: it is not a complete copy + // of anything, and once the write fails nothing else removes it. The unlink is + // retried once (Windows reports EPERM for a file whose handle has not been + // released yet); if it still fails the path is carried on the thrown error + // instead of being dropped where no caller can act on it. + const orphanPath = backupPath + let backupCleanupError: unknown = null + for (let attempt = 0; attempt < 2; attempt++) { + try { + await fs.unlink(orphanPath) + backupCleanupError = null + break + } catch (cleanupError: unknown) { + if (errorCode(cleanupError) === "ENOENT") { + // Already gone: that is exactly the outcome the cleanup wanted, so stop + // rather than unlinking the same path a second time. + backupCleanupError = null + break + } + backupCleanupError = cleanupError + } + } + backupPath = null + if (backupCleanupError !== null) { + throw new OrphanedBackupError(orphanPath, targetPath, backupError, backupCleanupError) + } + throw backupError + } + releaseBackupOnSuccess = true + } catch (err: unknown) { + if (errorCode(err) !== "ENOENT") throw err + } + } + + // -- Step 4: atomic commit temp -> target --------------------- + if (options?.failIfExist) { + // No-replace commit: link(2) fails EEXIST when the name already exists, + // where a rename would silently displace whatever a non-participating + // writer put there after the caller checked. The staged copy is removed + // once the name points at it. + try { + await fs.link(tempPath, targetPath) + } catch (error: unknown) { + const code = errorCode(error) + if (code === "EEXIST") { + throw new TargetExistsError(targetPath) + } + // FAT32/exFAT volumes and some SMB/network mounts have no hard links, where + // link(2) fails EPERM/ENOTSUP/ENOSYS. Fall back to an exclusive copy so a + // create still works there: copyFile with COPYFILE_EXCL still fails EEXIST + // when the name exists, so the no-replace verdict is unchanged. Unlike link(2) + // the copy is not atomic - a reader can observe a partial file - so it is only + // used when the atomic primitive is unavailable. + if (code !== "EPERM" && code !== "ENOTSUP" && code !== "ENOSYS") { + throw error + } + try { + await fs.copyFile(tempPath, targetPath, fsSync.constants.COPYFILE_EXCL) + } catch (copyError: unknown) { + if (errorCode(copyError) === "EEXIST") { + throw new TargetExistsError(targetPath) + } + throw copyError + } + } + } else { + await fs.rename(tempPath, targetPath) + } + + if (options?.failIfExist) { + // The target name is published at this point; the staged name is only a second + // link to the same inode (or a copy of it). Removal is best-effort: on Windows + // an antivirus handle can make unlink fail with EBUSY/EPERM after the content + // is already visible, and the write must not be reported as failed for content + // the caller can now read back. + await fs.unlink(tempPath).catch(() => undefined) + } + + // -- Step 4b (POSIX): fsync the parent directory so the directory entry + // changed by the commit rename is durable, not just the file content. + if (platform !== "win32") { + try { + const dirFd = fsSync.openSync(dirPath, "r") + try { + _fsyncFile(dirFd) + } finally { + fsSync.closeSync(dirFd) + } + } catch (error: unknown) { + // The content rename committed, but the directory entry that + // points at it is not known to be durable. Reporting success + // here would let a caller believe the write survives a crash, + // so the failure is surfaced as its own error: the caller can + // still find the content at the target, it just cannot rely on + // the directory entry having reached the disk. + throw new PostCommitDurabilityError(targetPath, error) + } + } + + // -- Step 5 (win32): restore DACL AFTER commit rename --------- + // daclDumpPath is non-null only when the win32 step-2 block saved a + // successful dump, so this gate is closed on every other platform + // and on every failed save. + if (daclDumpPath !== null) { + const restoredDir = path.dirname(targetPath) + await _restoreDaclWindows(restoredDir, daclDumpPath, options?.execFileRunner) + } + + // -- Step 6 (backup:true): delete backup on success ----------- + if (releaseBackupOnSuccess && backupPath) { + try { + await fs.unlink(backupPath) + } catch { + // non-fatal — orphaned backup is acceptable + } + } + + } finally { + // Unlink DACL dump regardless of success/failure in this span. + if (daclDumpPath !== null) { + await fs.unlink(daclDumpPath).catch(() => {}) + } + } + + // tempPath is now the committed file; no cleanup needed. + + // Best-effort: remove the now-empty staging directory. Self-staged + // writes only, and only this write's own directory: a per-write directory + // cannot be the one another concurrent write is still using. A failure must + // never un-commit a published file, so the removal swallows all errors. + if (stagingDir) { + await fs.rmdir(stagingDir).catch(() => {}) + } + } catch (originalError: unknown) { + // The backup is a copy, never a restore source: whether the failure happened before + // or after the commit rename, the copy is removed below so no stale duplicate of the + // previous content survives next to the target. + if (backupPath && releaseBackupOnSuccess) { + // Nothing to restore: the backup is a copy, so the target still holds whatever + // the commit left there - before the commit that is the pre-write content, and + // after it the published content. Either way the copy has served its purpose + // and must not be left beside the target where no caller can find it. + await fs.unlink(backupPath).catch(() => {}) + backupPath = null + } + try { + await fs.unlink(tempPath).catch(() => {}) + } catch { + // cleanup failure is non-fatal + } + + // A failed self-staged write must not leave its staging directory behind. + // Only the directory this write created, and only after its temp file is + // gone, so the directory is empty and the removal stays best-effort. + if (stagingDir) { + await fs.rmdir(stagingDir).catch(() => {}) + } + + if (daclDumpPath !== null) { + await fs.unlink(daclDumpPath).catch(() => {}) + } + + + throw originalError + } +} diff --git a/src/utils/__tests__/fileLock.spec.ts b/src/utils/__tests__/fileLock.spec.ts new file mode 100644 index 0000000000..56b6d9e951 --- /dev/null +++ b/src/utils/__tests__/fileLock.spec.ts @@ -0,0 +1,110 @@ +// npx vitest run utils/__tests__/fileLock.spec.ts + +import * as path from "path" + +import * as fsPromises from "fs/promises" + +import * as lockfile from "proper-lockfile" + +import { acquireFileLock, withFileLock } from "../fileLock" + +vi.mock("fs/promises", () => ({ + realpath: vi.fn(async (target: unknown) => { + const asString = String(target) + // A path that does not exist yet reports ENOENT, as the real fs does. + if (asString.includes("missing")) { + throw Object.assign(new Error("ENOENT"), { code: "ENOENT" }) + } + return asString.replace("aliasDir", "realDir") + }), + // A non-link rejects readlink, exactly like the real fs; the link tests + // override this per path. + readlink: vi.fn(async () => { + throw Object.assign(new Error("EINVAL"), { code: "EINVAL" }) + }), +})) + +vi.mock("proper-lockfile", () => ({ + lock: vi.fn(async () => async () => {}), +})) + +/** + * proper-lockfile derives its lock file from the path it is handed, and this module + * turns off the library's own realpath step because the file may not exist yet. Without + * a canonical lock key, a writer that reaches a file through a symlinked directory and a + * deleter that reaches the same file lexically take DIFFERENT locks and silently lose + * updates against each other - the shape a task file under a symlinked task directory + * has against a task-history delete. + */ +const STORE = path.resolve("/tmp/store") + +describe("fileLock - canonical lock keys", () => { + beforeEach(() => { + vi.mocked(lockfile.lock).mockClear() + }) + + test("locks the referent when the path runs through a symlinked directory", async () => { + const releaseLock = await acquireFileLock(path.join(STORE, "aliasDir", "task.json")) + + expect(lockfile.lock).toHaveBeenCalledWith( + path.join(STORE, "realDir", "task.json"), + expect.objectContaining({ realpath: false }), + ) + + await releaseLock() + }) + + test("locks the referent but hands the operation the caller's own path", async () => { + // The mutex key is canonical; the path the caller works on is left alone. On Windows + // realpath can answer with the 8.3 short form, and rewriting the path a caller + // unlinks or compares would change behavior for every caller for no mutex gain. + const callerPath = path.join(STORE, "aliasDir", "task.json") + const seen: string[] = [] + await withFileLock(callerPath, async (absoluteFilePath) => { + seen.push(absoluteFilePath) + }) + + expect(seen).toEqual([callerPath]) + expect(lockfile.lock).toHaveBeenCalledWith( + path.join(STORE, "realDir", "task.json"), + expect.objectContaining({ realpath: false }), + ) + }) + + test("canonicalizes the nearest existing ancestor when the file does not exist yet", async () => { + // The file and its parent are absent, so realpath reports ENOENT for them; the deepest + // existing ancestor is resolved and the missing components are re-appended. + const seen: string[] = [] + await withFileLock( + path.join(STORE, "aliasDir", "missing", "new.json"), + async (absoluteFilePath) => { + seen.push(absoluteFilePath) + }, + ) + + expect(seen).toEqual([path.join(STORE, "aliasDir", "missing", "new.json")]) + expect(lockfile.lock).toHaveBeenCalledWith( + path.join(STORE, "realDir", "missing", "new.json"), + expect.objectContaining({ realpath: false }), + ) + }) +}) + + test("locks the referent of a file symlink whose target is temporarily absent", async () => { + // A backup-mode commit renames the referent away and back. During that window the + // link is dangling, realpath fails, and a naive fallback re-appends the LINK's + // basename onto the canonical parent - a different key from the one safeWriteJson + // holds through resolveLockKey, so the two writers stop excluding each other. + const linkPath = path.join(STORE, "link.json") + const referent = path.join(STORE, "referent.json") + vi.mocked(fsPromises.readlink).mockImplementation(async (p: unknown) => { + if (String(p) === linkPath) return referent + throw Object.assign(new Error("EINVAL"), { code: "EINVAL" }) + }) + + const releaseLock = await acquireFileLock(linkPath) + + expect(lockfile.lock).toHaveBeenCalledWith(referent, expect.objectContaining({ realpath: false })) + + await releaseLock() + }) diff --git a/src/utils/__tests__/safeWriteJson.lockKey.spec.ts b/src/utils/__tests__/safeWriteJson.lockKey.spec.ts new file mode 100644 index 0000000000..33989f8b81 --- /dev/null +++ b/src/utils/__tests__/safeWriteJson.lockKey.spec.ts @@ -0,0 +1,183 @@ +// npx vitest run utils/__tests__/safeWriteJson.lockKey.spec.ts + +import * as os from "os" +import path from "path" +import type { BigIntStats } from "fs" +import * as fs from "fs/promises" +import { acquireFileLock } from "../fileLock" +import { safeWriteJson } from "../safeWriteJson" +import { resolveLockKey } from "../../services/file-safety/safeWriteText" + +vi.mock("../fileLock", () => ({ + acquireFileLock: vi.fn(async () => async () => {}), +})) + +vi.mock("fs/promises", async () => { + const actual = await vi.importActual("fs/promises") + return { ...actual, realpath: vi.fn(), lstat: vi.fn(), readlink: vi.fn() } +}) + +const mockedRealpath = vi.mocked(fs.realpath) +const mockedLstat = vi.mocked(fs.lstat) +const mockedReadlink = vi.mocked(fs.readlink) +const mockedAcquireFileLock = vi.mocked(acquireFileLock) + +const enoent = Object.assign(new Error("ENOENT: no such file or directory"), { code: "ENOENT" }) + +// Each test creates a real temp directory so the real fs calls still work. +// doubles between tests so an implementation from one test cannot carry over. +const createdDirs: string[] = [] +async function makeDir(prefix: string): Promise { + const dir = await fs.mkdtemp(path.join(os.tmpdir(), prefix)) + createdDirs.push(dir) + return dir +} + +beforeEach(() => { + mockedRealpath.mockReset() + mockedLstat.mockReset() + mockedReadlink.mockReset() + mockedAcquireFileLock.mockReset() +}) + +afterEach(async () => { + for (const dir of createdDirs) { + await fs.rm(dir, { recursive: true, force: true }).catch(() => undefined) + } + createdDirs.length = 0 +}) + +// Only isSymbolicLink() is consulted by the guard, so the double carries just +// that method. The mocks reject asynchronously: a synchronous throw would bypass +// resolvePublishTarget's catch and skip the ENOENT/symlink branch under test. +const symlinkStat = (target: unknown) => ({ + isSymbolicLink: () => target === currentLink, + // The staging-path check in safeWriteText also asks whether the path is a + // regular file, so the double carries that predicate as well. + isFile: () => target !== currentLink, +}) as unknown as BigIntStats +let currentLink = "" + +describe("safeWriteJson lock key under a peer commit", () => { + it("waits for the peer instead of rejecting, and locks the referent", async () => { + const order: string[] = [] + const dir = await makeDir("lockkey-") + const referent = path.join(dir, "history_item.json") + currentLink = path.join(dir, "link.json") + + // The peer writer has renamed the referent away and has not committed yet, + // so the first resolution fails with ENOENT while lstat still reports a + // symbolic link. A strict resolve here rejects the caller before it can ever + // queue behind the peer, and the caller's delta write is lost. + mockedRealpath + .mockImplementationOnce(async () => { + order.push("resolve-failed") + throw enoent + }) + .mockImplementation(async (target) => { + order.push("resolve") + // The second call happens under the lock, where the peer has committed. + return target === currentLink ? referent : String(target) + }) + mockedLstat.mockImplementation(async (target) => { + order.push("lstat") + return symlinkStat(target) + }) + mockedReadlink.mockImplementation(async (target) => + target === currentLink ? referent : Promise.reject(new Error("not a link")), + ) + mockedAcquireFileLock.mockImplementation(async () => { + order.push("lock") + return async () => {} + }) + + await safeWriteJson(currentLink, { id: "task-1" }) + + // The lock key is the key every other writer to this file uses, so the caller + // queued behind the peer instead of failing before the lock. + expect(mockedAcquireFileLock).toHaveBeenCalledWith(referent) + // The trailing lstat is safeWriteText's staging-path check on the temp file + // this write created: it runs after the key was resolved and the lock taken, + // so it does not change which lock the caller queued behind. + expect(order).toEqual(["resolve-failed", "lstat", "resolve", "resolve", "lock", "resolve", "resolve", "lstat"]) + expect(JSON.parse(await fs.readFile(referent, "utf8"))).toEqual({ id: "task-1" }) + }) + + it("releases the lock when the resolution under the lock rejects", async () => { + const order: string[] = [] + let released = false + const dir = await makeDir("lockkey-") + const referent = path.join(dir, "history_item.json") + currentLink = path.join(dir, "link.json") + + // A real dangling link: the walk tolerates it so the caller can queue behind + // the peer, but once the lock is held the strict rejection still applies. A + // rejection outside the protected block would leave the lock held until the + // stale timeout for every other writer to the same file. + mockedRealpath.mockImplementation(async () => { + throw enoent + }) + mockedLstat.mockImplementation(async (target) => { + order.push("lstat") + return symlinkStat(target) + }) + mockedReadlink.mockImplementation(async (target) => + target === currentLink ? referent : Promise.reject(new Error("not a link")), + ) + mockedAcquireFileLock.mockImplementation(async () => { + order.push("lock") + return async () => { + order.push("release") + released = true + } + }) + + await expect(safeWriteJson(currentLink, { id: "task-1" })).rejects.toThrow(enoent) + expect(released).toBe(true) + // The strict rejection is reached through the ENOENT + symlink branch, not + // through a synchronous throw that skips it. + expect(order).toEqual(["lstat", "lock", "lstat", "release"]) + }) + + it("canonicalizes the parent directory when the file itself is not there yet", async () => { + // fs.realpath canonicalizes every component, including a symlinked ancestor + // directory or a Windows 8.3 short name. If the fallback returns the alias + // directory, the key depends on whether the file exists at the moment the key + // is computed, and a writer that resolved the canonical directory takes a + // different lock for the same file. + const aliasDir = path.join(os.tmpdir(), "alias-dir") + const canonicalDir = path.join(os.tmpdir(), "canonical-dir") + const file = path.join(aliasDir, "history_item.json") + mockedRealpath.mockImplementation(async (target) => { + if (target === file) throw enoent + return canonicalDir + }) + mockedLstat.mockImplementation(async () => ({ isSymbolicLink: () => false, isFile: () => true }) as unknown as BigIntStats) + + expect(await resolveLockKey(file)).toBe(path.join(canonicalDir, "history_item.json")) + }) +}) + +it("does not log a cleanup error when the safety net finds the temp file already gone", async () => { + // safeWriteText removes its own temp file on failure, so the safety net in + // safeWriteJson normally finds it gone. That is the expected outcome, not a + // second failure, and it must not be logged as one. + const dir = await makeDir("cleanup-") + const target = path.join(dir, "history_item.json") + currentLink = "" + mockedRealpath.mockImplementation(async (t) => String(t)) + mockedLstat.mockImplementation(async (t) => symlinkStat(t)) + + const renameSpy = vi.spyOn(fs, "rename").mockRejectedValue(new Error("commit rename failed")) + const unlinkSpy = vi.spyOn(fs, "unlink").mockRejectedValue(enoent) + const consoleError = vi.spyOn(console, "error").mockImplementation(() => {}) + + await expect(safeWriteJson(target, { id: "task-1" })).rejects.toThrow("commit rename failed") + + // Only the original failure is reported. + expect(consoleError).toHaveBeenCalledTimes(1) + + renameSpy.mockRestore() + unlinkSpy.mockRestore() + consoleError.mockRestore() +}) diff --git a/src/utils/__tests__/safeWriteJson.test.ts b/src/utils/__tests__/safeWriteJson.test.ts index 79d08678a0..d7bd76dfb2 100644 --- a/src/utils/__tests__/safeWriteJson.test.ts +++ b/src/utils/__tests__/safeWriteJson.test.ts @@ -4,6 +4,7 @@ import * as path from "path" import * as os from "os" import { safeWriteJson } from "../safeWriteJson" +import * as lockfile from "proper-lockfile" // Capture actual implementations before the vi.mock factory runs, // so they are never wrapped by vi.fn() — avoids infinite recursion when @@ -158,7 +159,7 @@ describe("safeWriteJson", () => { expect(content).toEqual({ initial: "content" }) }) - test("should handle failure when renaming filePath to tempBackupFilePath (filePath exists)", async () => { + test("should handle failure when the commit rename fails (filePath exists)", async () => { const initialData = { message: "Initial content, should remain" } const newData = { message: "New content, should not be written" } @@ -177,7 +178,7 @@ describe("safeWriteJson", () => { expect(content).toEqual(initialData) }) - test("should handle failure when renaming tempNewFilePath to filePath (filePath exists, backup succeeded)", async () => { + test("should handle failure when renaming tempNewFilePath to filePath (filePath exists, backup copy taken)", async () => { const initialData = { message: "Initial content, should be restored" } const newData = { message: "New content" } @@ -191,14 +192,8 @@ describe("safeWriteJson", () => { vi.mocked(fs.rename).mockImplementation(async (oldPath, newPath) => { renameCallCount++ if (renameCallCount === 1) { - // First call: filePath -> tempBackupFilePath (should succeed) - return fsPromisesActuals.rename!(oldPath, newPath) - } else if (renameCallCount === 2) { - // Second call: tempNewFilePath -> filePath (should fail) + // The commit rename is the only rename in this flow: it fails. throw new Error("Rename from temp to final failed") - } else if (renameCallCount === 3) { - // Third call: tempBackupFilePath -> filePath (rollback, should succeed) - return fsPromisesActuals.rename!(oldPath, newPath) } // Default: use original implementation return fsPromisesActuals.rename!(oldPath, newPath) @@ -312,9 +307,8 @@ describe("safeWriteJson", () => { expect(content).toEqual(newData) }) - // Test for console error suppression during backup deletion - test("should suppress console.error when backup deletion fails", async () => { - const consoleErrorSpy = vi.spyOn(console, "error").mockImplementation(() => {}) // Suppress console.error + // Test for best-effort backup deletion (the backup lifecycle now lives in safeWriteText) + test("does not fail the write when backup deletion fails (orphaned backup is acceptable)", async () => { const initialData = { message: "Initial" } const newData = { message: "New" } @@ -322,18 +316,23 @@ describe("safeWriteJson", () => { // fs.unlink is already vi.fn() — use vi.mocked to avoid double-wrapping via vi.spyOn vi.mocked(fs.unlink).mockImplementation(async (filePath: any) => { - if (filePath.toString().includes(".bak_")) { + if (filePath.toString().includes("safeWriteText.bak_")) { throw new Error("Backup deletion failed") } return fsPromisesActuals.unlink!(filePath) }) + // The write must still succeed: backup cleanup is best-effort inside + // safeWriteText and never masks the committed content. await safeWriteJson(currentTestFilePath, newData) - // Verify console.error was called with the expected message - expect(consoleErrorSpy).toHaveBeenCalledWith(expect.stringContaining("Successfully wrote"), expect.any(Error)) + const content = await readFileContent(currentTestFilePath) + expect(content).toEqual(newData) + + // The orphaned backup is still on disk because its deletion failed. + const entries = await fs.readdir(tempDir) + expect(entries.some((entry) => entry.includes("safeWriteText.bak_"))).toBe(true) - consoleErrorSpy.mockRestore() vi.mocked(fs.unlink).mockRestore() }) @@ -345,16 +344,11 @@ describe("safeWriteJson", () => { await fsPromisesActuals.writeFile!(currentTestFilePath, JSON.stringify(initialData)) - // fs.rename is already vi.fn() — use vi.mocked to avoid double-wrapping via vi.spyOn - let renameCallCount = 0 - vi.mocked(fs.rename).mockImplementation(async (oldPath, newPath) => { - renameCallCount++ - if (renameCallCount === 2) { - // Second call: tempNewFilePath -> filePath (should fail) - throw new Error("Rename failed") - } - // For all other calls, use the original implementation - return fsPromisesActuals.rename!(oldPath, newPath) + // fs.rename is already vi.fn() — use vi.mocked to avoid double-wrapping via vi.spyOn. + // Once-only so the override does not leak into later tests: the commit rename is + // the only rename in this flow. + vi.mocked(fs.rename).mockImplementationOnce(async () => { + throw new Error("Rename failed") }) await expect(safeWriteJson(currentTestFilePath, newData)).rejects.toThrow("Rename failed") @@ -434,9 +428,9 @@ describe("safeWriteJson", () => { expect(vi.mocked(fs.access)).toHaveBeenCalled() }) - // Test for rollback failure scenario - test("should log error and re-throw original if rollback fails", async () => { - const initialData = { message: "Initial, should be lost if rollback fails" } + // Test for rollback failure scenario (the rollback rename now lives in safeWriteText) + test("a failed commit keeps the previous content at the target and removes the backup copy", async () => { + const initialData = { message: "Initial, must survive a failed commit" } const newData = { message: "New content" } await fsPromisesActuals.writeFile!(currentTestFilePath, JSON.stringify(initialData)) @@ -447,24 +441,24 @@ describe("safeWriteJson", () => { let renameCallCount = 0 vi.mocked(fs.rename).mockImplementation(async (oldPath, newPath) => { renameCallCount++ - if (renameCallCount === 2) { - // Second call: tempNewFilePath -> filePath (fail) + if (renameCallCount === 1) { + // The commit rename fails; there is no rollback rename to fail. throw new Error("Primary rename failed") - } else if (renameCallCount === 3) { - // Third call: tempBackupFilePath -> filePath (rollback, also fail) - throw new Error("Rollback rename failed") } return fsPromisesActuals.rename!(oldPath, newPath) }) - // Should throw the original error, not the rollback error await expect(safeWriteJson(currentTestFilePath, newData)).rejects.toThrow("Primary rename failed") - // Verify console.error was called for the rollback failure - expect(consoleErrorSpy).toHaveBeenCalledWith( - expect.stringContaining("Failed to restore backup"), - expect.objectContaining({ message: "Rollback rename failed" }), - ) + // Exactly one rename was attempted, and it was the commit. + expect(renameCallCount).toBe(1) + + // The target never left its path, so the previous content is still what a + // reader sees, and no orphaned backup copy is left behind either. + const content = await readFileContent(currentTestFilePath) + expect(content).toEqual(initialData) + const entries = await fs.readdir(tempDir) + expect(entries.some((entry) => entry.includes("safeWriteText.bak_"))).toBe(false) consoleErrorSpy.mockRestore() }) @@ -542,4 +536,144 @@ describe("safeWriteJson", () => { const content = await readFileContent(currentTestFilePath) expect(content).toEqual({ c: 3 }) }) + + // The commit rename targets the symlink referent. The staged temp file must + // therefore be created beside the RESOLVED target — staging beside the link + // would make the commit rename fail with EXDEV when the referent is on + // another filesystem. (Real symlinks are unavailable in this CI lane, so the + // resolution is simulated by mocking fs.realpath the same way.) + test("stages the temp file beside the symlink referent and commits onto it", async () => { + const referentDir = path.join(tempDir, "referent") + const linkDir = path.join(tempDir, "link") + await fs.mkdir(referentDir, { recursive: true }) + await fs.mkdir(linkDir, { recursive: true }) + // caller-visible path (the link) vs the resolved referent path + const callerPath = path.join(linkDir, "test-file.json") + const referentPath = path.join(referentDir, "test-file.json") + // Seed the RESOLVED referent with real content (via the actual fs) so the + // write exercises replacement of an EXISTING referent: the lock, the + // backup, and the commit all target the resolved referent. + await fsPromisesActuals.writeFile!(referentPath, JSON.stringify({ seed: true })) + + // Only the file resolves through the link; the directory is already canonical, + // so the lock key is the referent rather than the alias directory + basename. + vi.spyOn(fs, "realpath").mockImplementation(async (target) => + target === callerPath ? referentPath : String(target), + ) + + await safeWriteJson(callerPath, { after: true }) + + // the temp file was created next to the resolved referent, NOT beside the link + const tempPaths = vi.mocked(fsSyncActual.createWriteStream).mock.calls.map((call) => String(call[0])) + expect(tempPaths.some((p) => p.startsWith(referentDir + path.sep) && p.includes(".new_"))).toBe(true) + expect(tempPaths.some((p) => p.startsWith(linkDir + path.sep))).toBe(false) + + // the content was committed onto the referent + expect(await readFileContent(referentPath)).toEqual({ after: true }) + }) + + // proper-lockfile with realpath:false keys the lock by the given path, so a + // symlink alias and its referent must coordinate through ONE lock on the + // resolved referent — otherwise a concurrent merge through both aliases + // reads the same JSON and overwrites one update. (Real symlinks are + // unavailable in this CI lane, so the resolution is simulated by mocking + // fs.realpath, the same way as the staging test above.) + test("acquires the lock on the resolved referent, not the caller alias", async () => { + vi.resetModules() // fresh module instances so the doMock below is picked up + + const referentDir = path.join(tempDir, "lock-referent") + const linkDir = path.join(tempDir, "lock-link") + await fs.mkdir(referentDir, { recursive: true }) + await fs.mkdir(linkDir, { recursive: true }) + // caller-visible path (the link) vs the resolved referent path + const callerPath = path.join(linkDir, "locked.json") + const referentPath = path.join(referentDir, "locked.json") + await fsPromisesActuals.writeFile!(referentPath, JSON.stringify({ seed: 1 })) + + // Only the file resolves through the link; the directory is already canonical, + // so the lock key is the referent rather than the alias directory + basename. + const realpathSpy = vi + .spyOn(fs, "realpath") + .mockImplementation(async (target) => (target === callerPath ? referentPath : String(target))) + + // Wrap the real lock in a capturing mock, and drive the two rare error paths + // (the onCompromised callback and a failing release) so they stay covered + // without real lockfile staleness. The callback rethrows by design, so + // the mock swallows that throw and lets the real lock proceed. + const realLockfile = await vi.importActual("proper-lockfile") + const lockMockFn = vi.fn( + async ( + file: Parameters[0], + options?: Parameters[1], + ) => { + try { + options?.onCompromised?.(new Error("lock compromised (test)")) + } catch { + // onCompromised rethrows by design; swallow so the real lock proceeds. + } + const release = await realLockfile.lock(file, options) + return async () => { + await release() + throw new Error("release failed (test)") + } + }, + ) + const lockMock = lockMockFn as unknown as typeof realLockfile.lock + vi.doMock("proper-lockfile", () => ({ + ...realLockfile, + lock: lockMock, + })) + + // Re-import safeWriteJson so it picks up the mocked proper-lockfile. + const { safeWriteJson: mockedSafeWriteJson } = await import("../safeWriteJson") + + const mergeFn = vi.fn((existing: unknown, incoming: unknown) => ({ + ...(existing as Record), + ...(incoming as Record), + })) + + // Capture the compromise + release-failure logs. + const consoleErrorSpy = vi.spyOn(console, "error") + try { + await mockedSafeWriteJson(callerPath, { added: true }, { merge: mergeFn }) + + // The lock was keyed by the resolved referent — every alias shares it. + expect(lockMock).toHaveBeenCalledTimes(1) + expect(String(lockMockFn.mock.calls[0][0])).toBe(referentPath) + // The merge read the referent's content through that single lock. + expect(mergeFn).toHaveBeenCalledWith({ seed: 1 }, { added: true }) + expect(await readFileContent(referentPath)).toEqual({ seed: 1, added: true }) + // The compromise callback and the failed release were logged, not thrown. + expect(consoleErrorSpy).toHaveBeenCalledWith(expect.stringContaining("was compromised"), expect.any(Error)) + expect(consoleErrorSpy).toHaveBeenCalledWith( + expect.stringContaining("Failed to release lock"), + expect.any(Error), + ) + } finally { + // Cleanup must run even when an assertion fails: a leaked mock + // registration or console spy changes later tests, and vi.unmock + // alone does not reset a module that already imported the mock. + realpathSpy.mockRestore() + vi.unmock("proper-lockfile") + vi.resetModules() + consoleErrorSpy.mockRestore() + } + }) + + // CWE-732 regression: safeWriteJson stages the temp itself and passes it + // via tempPath, so safeWriteText must apply the existing target's mode to + // the staged temp before the atomic rename — otherwise a 0o600 target is + // published as 0o644. POSIX-only assertion (Windows ignores POSIX modes). + test.skipIf(process.platform === "win32")( + "preserves a restrictive 0o600 target mode through the atomic publish", + async () => { + await fsPromisesActuals.writeFile!(currentTestFilePath, JSON.stringify({ before: true })) + fsSyncActual.chmodSync(currentTestFilePath, 0o600) + + await safeWriteJson(currentTestFilePath, { after: true }) + + expect(fsSyncActual.statSync(currentTestFilePath).mode & 0o777).toBe(0o600) + expect(await readFileContent(currentTestFilePath)).toEqual({ after: true }) + }, + ) }) diff --git a/src/utils/fileLock.ts b/src/utils/fileLock.ts index 9f7cad7653..8a227f0dae 100644 --- a/src/utils/fileLock.ts +++ b/src/utils/fileLock.ts @@ -1,5 +1,6 @@ import * as path from "path" import * as lockfile from "proper-lockfile" +import * as fs from "fs/promises" /** * Shared staleness window for per-file advisory locks. This module owns the @@ -8,6 +9,62 @@ import * as lockfile from "proper-lockfile" */ export const LOCK_STALE_MS = 31_000 +/** + * Canonical lock key for a path. + * + * proper-lockfile derives its lock file from the path it is handed, and this module + * turns off the library's own realpath step because the file may not exist yet. Two + * callers that reach the same file by different routes - one lexical, one through a + * symlinked directory - would then take DIFFERENT locks and silently lose updates + * against each other, which is exactly how a task file written through a symlinked + * task directory ends up unlocked against a task-history delete. + * + * The file itself may be absent (a create), so the nearest EXISTING ancestor is + * canonicalized and the missing components are re-appended. If nothing can be + * canonicalized the lexical absolute path is kept: lock keys stay stable and the + * write's own resolution still decides where content lands. + */ +async function canonicalLockPath(filePath: string): Promise { + const absoluteFilePath = path.resolve(filePath) + + // A file symlink has to produce the same key the writer's lock uses + // (resolveLockKey in safeWriteText). Walking readlink even when the referent is + // temporarily absent - which is exactly the window a backup-mode commit creates - + // keeps a raw withFileLock caller on the link path excluding the peer writing + // through the referent; re-appending the link's basename onto the canonical + // parent would take a different lock and the two operations would stop excluding + // each other. The walk is bounded so a two-link cycle terminates. + let linkCursor = absoluteFilePath + for (let depth = 0; depth < 8; depth++) { + const referent = await fs.readlink(linkCursor).catch(() => undefined) + if (referent === undefined) { + break + } + linkCursor = path.resolve(path.dirname(linkCursor), referent) + } + if (linkCursor !== absoluteFilePath) { + return await canonicalLockPath(linkCursor) + } + const missing: string[] = [] + let cursor = absoluteFilePath + for (;;) { + try { + const realPath = await fs.realpath(cursor) + return missing.length > 0 ? path.join(realPath, ...missing.reverse()) : realPath + } catch (error) { + const code = + typeof error === "object" && error !== null && "code" in error + ? (error as { code?: string }).code + : undefined + if (code !== "ENOENT" && code !== "ENOTDIR") return absoluteFilePath + const parent = path.dirname(cursor) + if (parent === cursor) return absoluteFilePath + missing.push(path.basename(cursor)) + cursor = parent + } + } +} + /** * Acquire the advisory lock for one file path using the exact protocol * `safeWriteJson` uses, so operations that hold this lock serialize with @@ -16,7 +73,7 @@ export const LOCK_STALE_MS = 31_000 * while holding it. */ export async function acquireFileLock(filePath: string): Promise<() => Promise> { - const absoluteFilePath = path.resolve(filePath) + const absoluteFilePath = await canonicalLockPath(filePath) try { return await lockfile.lock(absoluteFilePath, { stale: LOCK_STALE_MS, @@ -50,19 +107,25 @@ export async function withFileLock( filePath: string, operation: (absoluteFilePath: string) => Promise, ): Promise { - const absoluteFilePath = path.resolve(filePath) - const releaseLock = await acquireFileLock(absoluteFilePath) + // The LOCK key is canonical, so a caller that reaches the file through a symlinked + // directory and one that reaches it lexically contend for the same lock file. The + // operation still receives the caller's own absolute path: on Windows realpath can + // answer with the 8.3 short form (C:\Users\RUNNER~1\... for a temp dir under + // C:\Users\runneradmin\...), and rewriting the path a caller unlinks or compares + // would change behavior for every caller while adding nothing to the mutex. + const operationPath = path.resolve(filePath) + const releaseLock = await acquireFileLock(operationPath) let result: T try { - result = await operation(absoluteFilePath) + result = await operation(operationPath) } catch (operationError) { // The operation error is the primary failure. Release without // reporting a secondary release error over it. try { await releaseLock() } catch (releaseError) { - console.error(`Failed to release lock for ${absoluteFilePath}:`, releaseError) + console.error(`Failed to release lock for ${operationPath}:`, releaseError) } throw operationError } @@ -72,7 +135,7 @@ export async function withFileLock( } catch (releaseError) { // The operation already succeeded, so a release failure is only // logged, matching how `safeWriteJson` handles release failures. - console.error(`Failed to release lock for ${absoluteFilePath}:`, releaseError) + console.error(`Failed to release lock for ${operationPath}:`, releaseError) } return result } diff --git a/src/utils/safeWriteJson.ts b/src/utils/safeWriteJson.ts index 7da68b2a7a..bae200dd38 100644 --- a/src/utils/safeWriteJson.ts +++ b/src/utils/safeWriteJson.ts @@ -4,6 +4,12 @@ import * as path from "path" import { JsonStreamStringify } from "json-stream-stringify" import { acquireFileLock } from "./fileLock" +import { + resolveLockKey, + resolvePublishTarget, + safeWriteText, + type SafeWriteTextOptions, +} from "../services/file-safety/safeWriteText" /** * Options for safeWriteJson function @@ -32,7 +38,7 @@ export interface SafeWriteJsonOptions { * Safely writes JSON data to a file. * - Creates parent directories if they don't exist * - Uses 'proper-lockfile' for inter-process advisory locking to prevent concurrent writes to the same path. - * - Writes to a temporary file first. + * - Writes to a temporary file first via JsonStreamStringify streaming. * - If the target file exists, it's backed up before being replaced. * - Attempts to roll back and clean up in case of errors. * - Supports pretty-printing with indentation while maintaining streaming efficiency. @@ -42,7 +48,6 @@ export interface SafeWriteJsonOptions { * @param {SafeWriteJsonOptions} options - Optional configuration for JSON formatting. * @returns {Promise} */ - async function safeWriteJson(filePath: string, data: any, options?: SafeWriteJsonOptions): Promise { const absoluteFilePath = path.resolve(filePath) let releaseLock = async () => {} // Initialized to a no-op @@ -51,38 +56,46 @@ async function safeWriteJson(filePath: string, data: any, options?: SafeWriteJso const dirPath = path.dirname(absoluteFilePath) // Ensure directory structure exists with improved reliability + // Declared outside the protected block so the catch and finally can still name + // the target when the resolution itself rejects. + let resolvedTargetPath: string | undefined + try { - // Create directory with recursive option await fs.mkdir(dirPath, { recursive: true }) - - // Verify directory exists after creation attempt await fs.access(dirPath) } catch (dirError: any) { console.error(`Failed to create or access directory for ${absoluteFilePath}:`, dirError) throw dirError } - // Acquire the lock before any file operations. `acquireFileLock` owns the - // shared advisory lock protocol, so callers that lock the same path with - // it (for example task-history deletion) serialize with this write. - // If lock acquisition fails, it throws immediately. The releaseLock - // remains a no-op, so the finally block in the main file operations - // try-catch-finally won't try to release an unacquired lock if this - // path is taken. - releaseLock = await acquireFileLock(absoluteFilePath) + // Lock key: the symlink referent when the path is an existing symlink, so a + // symlink alias and its referent share one lock. The key must be computable + // while a peer writer is mid-commit (backup mode renames the referent away and + // back), so the walk tolerates a dangling link instead of rejecting it here. + const lockKey = await resolveLockKey(absoluteFilePath) - // Variables to hold the actual paths of temp files if they are created. + // Acquire the lock before any file operations. If acquisition fails it throws + // immediately, and releaseLock stays a no-op so the finally block does not try + // to release an unacquired lock. + releaseLock = await acquireFileLock(lockKey) + + // Variables to hold the actual path of the temp file if it is created. let actualTempNewFilePath: string | null = null - let actualTempBackupFilePath: string | null = null try { + // Resolve the publish target under the lock: the peer has committed by now, so + // the strict dangling-link rejection still applies to a real dangling link. It + // must stay inside the protected block, otherwise a rejection here leaves the + // advisory lock held until the stale timeout for every other writer. + resolvedTargetPath = await resolvePublishTarget(absoluteFilePath) + // If a merge callback was provided, read the current file under the lock // and let the caller merge before we write. Must be inside try/finally // so a throwing merge still releases the lock. if (options?.merge) { let existing: unknown = null try { - existing = JSON.parse(await fs.readFile(absoluteFilePath, "utf8")) + existing = JSON.parse(await fs.readFile(resolvedTargetPath, "utf8")) } catch (error: unknown) { const code = error && typeof error === "object" && "code" in error ? (error as { code: string }).code : undefined @@ -93,111 +106,73 @@ async function safeWriteJson(filePath: string, data: any, options?: SafeWriteJso data = options.merge(existing, data) } - // Step 1: Write data to a new temporary file. + // Step 1: Write data to a new temporary file via JSON streaming. + // Stage it beside the *resolved* target (the symlink referent when the path is + // a symlink; resolvedTargetPath above): safeWriteText commits by renaming + // onto that referent, and a rename across filesystems would fail with EXDEV. actualTempNewFilePath = path.join( - path.dirname(absoluteFilePath), - `.${path.basename(absoluteFilePath)}.new_${Date.now()}_${Math.random().toString(36).substring(2)}.tmp`, + path.dirname(resolvedTargetPath), + ".new_" + Date.now() + "_" + Math.random().toString(36).substring(2) + ".tmp", ) await _streamDataToFile(actualTempNewFilePath, data, options?.prettyPrint) - // Step 2: Check if the target file exists. If so, rename it to a backup path. - try { - // Check for target file existence - await fs.access(absoluteFilePath) - // Target exists, create a backup path and rename. - actualTempBackupFilePath = path.join( - path.dirname(absoluteFilePath), - `.${path.basename(absoluteFilePath)}.bak_${Date.now()}_${Math.random().toString(36).substring(2)}.tmp`, - ) - await fs.rename(absoluteFilePath, actualTempBackupFilePath) - } catch (accessError: any) { - // Explicitly type accessError - if (accessError.code !== "ENOENT") { - // An error other than "file not found" occurred during access check. - throw accessError - } - // Target file does not exist, so no backup is made. actualTempBackupFilePath remains null. + // Step 2: Delegate backup + commit + rollback to safeWriteText with the + // pre-written temp path. backup:true keeps the old safeWriteJson + // semantics (target -> backup before commit, rollback on failure) and + // keeps the target in place until safeWriteText captures its Windows + // DACL (safeWriteText dumps the DACL before its own backup rename and + // restores it onto the directory after the commit rename). + const textOptions: SafeWriteTextOptions = { + tempPath: actualTempNewFilePath, + backup: true, } - // Step 3: Rename the new temporary file to the target file path. - // This is the main "commit" step. - await fs.rename(actualTempNewFilePath, absoluteFilePath) + await safeWriteText(resolvedTargetPath, "", textOptions) - // If we reach here, the new file is successfully in place. - // The original actualTempNewFilePath is now the main file, so we shouldn't try to clean it up as "temp". - // Mark as "used" or "committed" + // If we reach here, the new file is successfully in place and any + // backup has already been handled by safeWriteText. actualTempNewFilePath = null - - // Step 4: If a backup was created, attempt to delete it. - if (actualTempBackupFilePath) { - try { - await fs.unlink(actualTempBackupFilePath) - // Mark backup as handled - actualTempBackupFilePath = null - } catch (unlinkBackupError) { - // Log this error, but do not re-throw. The main operation was successful. - // actualTempBackupFilePath remains set, indicating an orphaned backup. - console.error( - `Successfully wrote ${absoluteFilePath}, but failed to clean up backup ${actualTempBackupFilePath}:`, - unlinkBackupError, - ) - } - } } catch (originalError) { - console.error(`Operation failed for ${absoluteFilePath}: [Original Error Caught]`, originalError) + console.error( + `Operation failed for ${resolvedTargetPath ?? absoluteFilePath}: [Original Error Caught]`, + originalError, + ) const newFileToCleanupWithinCatch = actualTempNewFilePath - const backupFileToRollbackOrCleanupWithinCatch = actualTempBackupFilePath - - // Attempt rollback if a backup was made - if (backupFileToRollbackOrCleanupWithinCatch) { - try { - await fs.rename(backupFileToRollbackOrCleanupWithinCatch, absoluteFilePath) - // Mark as handled, prevent later unlink of this path - actualTempBackupFilePath = null - } catch (rollbackError) { - // actualTempBackupFilePath (outer scope) remains pointing to backupFileToRollbackOrCleanupWithinCatch - console.error( - `[Catch] Failed to restore backup ${backupFileToRollbackOrCleanupWithinCatch} to ${absoluteFilePath}:`, - rollbackError, - ) - } - } - // Cleanup the .new file if it exists + // A failed safeWriteText already rolled the backup (if any) back to + // the target path. Clean up the .new file if it still exists + // (safeWriteText also cleans up its tempPath on failure; this is a + // safety net in case its cleanup missed it). if (newFileToCleanupWithinCatch) { try { await fs.unlink(newFileToCleanupWithinCatch) - } catch (cleanupError) { - console.error( - `[Catch] Failed to clean up temporary new file ${newFileToCleanupWithinCatch}:`, - cleanupError, - ) + } catch (cleanupError: unknown) { + // The expected case: safeWriteText already removed its own temp file, so a + // missing file here is not a cleanup failure worth logging. Returning would + // also swallow the original error the caller needs. + const isAbsent = + typeof cleanupError === "object" && + cleanupError !== null && + "code" in cleanupError && + cleanupError.code === "ENOENT" + if (!isAbsent) { + console.error( + `[Catch] Failed to clean up temporary new file ${newFileToCleanupWithinCatch}:`, + cleanupError, + ) + } } } - // Cleanup the .bak file if it still needs to be (i.e., wasn't successfully restored) - if (actualTempBackupFilePath) { - try { - await fs.unlink(actualTempBackupFilePath) - } catch (cleanupError) { - console.error( - `[Catch] Failed to clean up temporary backup file ${actualTempBackupFilePath}:`, - cleanupError, - ) - } - } throw originalError // This MUST be the error that rejects the promise. } finally { // Release the lock in the main finally block. try { - // releaseLock will be the actual unlock function if lock was acquired, - // or the initial no-op if acquisition failed. await releaseLock() } catch (unlockError) { - // Do not re-throw here, as the originalError from the try/catch (if any) is more important. - console.error(`Failed to release lock for ${absoluteFilePath}:`, unlockError) + console.error(`Failed to release lock for ${resolvedTargetPath ?? absoluteFilePath}:`, unlockError) } } }