ref: Prefer spread over Array.from() repo-wide

.oxlintrc.json

@@ -37,7 +37,8 @@
         "allow": ["URL", "URLSearchParams"]
       }
     ],
-    "jsx-a11y/interactive-supports-focus": "off"
+    "jsx-a11y/interactive-supports-focus": "off",
+    "unicorn/prefer-spread": "error"
   },
   "overrides": [
     {

apps/docs-mcp/src/agent/query-agent.ts

@@ -52,10 +52,10 @@ function canonicalizeDocsUrl(value: string): string {
 
   url.search = "";
   url.hash = "";
-  url.pathname = url.pathname
+  const pathname = url.pathname
     .replace(TRAILING_MD_RE, "")
-    .replace(TRAILING_SLASHES_RE, "")
-    .concat("/");
+    .replace(TRAILING_SLASHES_RE, "");
+  url.pathname = `${pathname}/`;
   return url.toString();
 }
 

docs/contributing/coding-guidelines.md

@@ -35,6 +35,14 @@ product-specific implementation patterns.
   write `return await` in async functions so callers stay in async stack
   traces. Type-aware correctness rules that still have a backlog are turned
   off at the root; #1573 tracks enabling them.
+- Copy and combine iterables with spread: `[...set]`, `[...a, ...b]`,
+  `[...path, key]`. `unicorn/prefer-spread` enforces this repo-wide and
+  autofixes `Array.from(x)` and `.slice()`. Spread rejects non-iterables at
+  compile time and at runtime, where `Array.from` accepts any `{ length }`
+  object. Keep `Array.from` for array-likes and `Array.from({ length: n }, fn)`.
+  To walk a string's UTF-16 code units, use `split("")`. Spread a string only
+  when you mean code points, and suppress `typescript/no-misused-spread` with
+  the reason.
 - Don't pass an async callback to `.catch()`. Use `try`/`await`/`catch`, or a
   wrapper such as `withDashboardErrors(ctx, fn)`. The `no-async-catch-callback`
   ast-grep rule enforces this.

packages/cli/script/generate-docs-sections.ts

@@ -162,9 +162,7 @@ function getSubcommandLabel(route: RouteInfo): string {
     const parts = cmd.path.split(" ");
     return parts.at(-1) ?? route.name;
   });
-  return Array.from(new Set(raw))
-    .sort((a, b) => a.localeCompare(b))
-    .join(", ");
+  return [...new Set(raw)].sort((a, b) => a.localeCompare(b)).join(", ");
 }
 
 /**

packages/cli/src/commands/explore.ts

@@ -103,7 +103,7 @@ const PAGINATION_KEY = "explore";
 
 const DATASETS = buildDatasetParser(
   ["errors", "spans", "tracemetrics", "logs", "replays"],
-  Array.from(LEGACY_TRANSACTION_DATASETS),
+  [...LEGACY_TRANSACTION_DATASETS],
 );
 
 // ---------------------------------------------------------------------------

packages/cli/src/commands/issue/merge.ts

@@ -118,7 +118,7 @@ async function resolveAllIssues(
   const orgs = new Set(resolved.map((r) => r.org as string));
   if (orgs.size > 1) {
     throw new ValidationError(
-      `Cannot merge issues across organizations (${Array.from(orgs).join(", ")}).\n\n` +
+      `Cannot merge issues across organizations (${[...orgs].join(", ")}).\n\n` +
         "All issues must belong to the same organization.",
     );
   }

packages/cli/src/commands/span/list.ts

@@ -143,7 +143,7 @@ function extractExtraApiFields(
     expanded.delete(known);
   }
 
-  return expanded.size > 0 ? Array.from(expanded) : undefined;
+  return expanded.size > 0 ? [...expanded] : undefined;
 }
 
 /** Accepted values for the --sort flag (matches trace list) */

packages/cli/src/commands/trace/view.ts

@@ -200,7 +200,7 @@ const PROGRESS_THRESHOLD = 20;
 export function flattenSpanTree(spans: TraceSpan[]): TraceSpan[] {
   const result: TraceSpan[] = [];
   // Reverse so the first child is popped first (depth-first order)
-  const stack = Array.from(spans).reverse();
+  const stack = [...spans].reverse();
   let span = stack.pop();
   while (span) {
     result.push(span);

packages/cli/src/lib/api/attribute-pagination.ts

@@ -39,7 +39,7 @@ function encodeBookmark(
   return (
     CURSOR_PREFIX +
     Buffer.from(
-      JSON.stringify({ cursor: cursor ?? null, seen: Array.from(seen) }),
+      JSON.stringify({ cursor: cursor ?? null, seen: [...seen] }),
     ).toString("base64url")
   );
 }
@@ -126,7 +126,7 @@ export async function fetchAttributeTypePage(
             pending || next
               ? encodeBookmark(
                   next,
-                  Array.from(seen).filter((key) => keysOnPage.has(key)),
+                  [...seen].filter((key) => keysOnPage.has(key)),
                 )
               : undefined,
         };
@@ -170,6 +170,6 @@ export function attributeCursorAfter(
   const keysOnPage = page.pageKeys.get(pageId(replay)) ?? new Set<string>();
   return encodeBookmark(
     replay,
-    Array.from(seen).filter((key) => keysOnPage.has(key)),
+    [...seen].filter((key) => keysOnPage.has(key)),
   );
 }

packages/cli/src/lib/api/issues.ts

@@ -167,9 +167,7 @@ export async function listIssuesPaginated(
 ): Promise<PaginatedResponse<SentryIssue[]>> {
   // Prefer the API's repeated `project` parameter. A lone slug retains the
   // search-query fallback for callers that have not resolved project identity.
-  const projects = options.projects?.length
-    ? Array.from(options.projects)
-    : undefined;
+  const projects = options.projects?.length ? [...options.projects] : undefined;
   const projectFilter =
     projects === undefined && projectSlug ? `project:${projectSlug}` : "";
   const fullQuery = [projectFilter, options.query].filter(Boolean).join(" ");

packages/cli/src/lib/api/traces.ts

@@ -718,7 +718,7 @@ async function fetchSpansPage(
   const fullQuery = [projectFilter, options.query].filter(Boolean).join(" ");
 
   const fields = options.extraFields?.length
-    ? SPAN_FIELDS.concat(options.extraFields)
+    ? [...SPAN_FIELDS, ...options.extraFields]
     : SPAN_FIELDS;
 
   let projectParam: string | undefined;

packages/cli/src/lib/attribute-search.ts

@@ -76,7 +76,7 @@ export function parseAttributeFilter(
     );
   }
   return {
-    query: hasTerms.size > 0 ? Array.from(hasTerms).join(" ") : undefined,
+    query: hasTerms.size > 0 ? [...hasTerms].join(" ") : undefined,
     name,
   };
 }
@@ -109,5 +109,5 @@ export function parseAttributeTypes(
     }
     types.add(value);
   }
-  return types.size > 0 ? Array.from(types) : undefined;
+  return types.size > 0 ? [...types] : undefined;
 }

packages/cli/src/lib/banner.ts

@@ -101,7 +101,8 @@ export const FULL_BANNER_LINES: BannerLine[] = colorize(BANNER_ROWS_FULL);
 export function bannerLinesWidth(lines: readonly BannerLine[]): number {
   let max = 0;
   for (const { content } of lines) {
-    const width = Array.from(content).length;
+    // oxlint-disable-next-line typescript/no-misused-spread -- width is measured in code points
+    const width = [...content].length;
     if (width > max) {
       max = width;
     }

packages/cli/src/lib/complete.ts

@@ -320,7 +320,7 @@ export function completeOrgSlugs(partial: string, suffix = ""): Completion[] {
   }
 
   const nameMap = new Map(orgs.map((o) => [o.slug, o.name]));
-  const matched = fuzzyMatch(partial, Array.from(nameMap.keys()), {
+  const matched = fuzzyMatch(partial, [...nameMap.keys()], {
     mode: "search",
   });
 
@@ -402,7 +402,7 @@ export function completeProjectSlugs(
   }
 
   const nameMap = new Map(projects.map((p) => [p.projectSlug, p.projectName]));
-  const matched = fuzzyMatch(projectPartial, Array.from(nameMap.keys()), {
+  const matched = fuzzyMatch(projectPartial, [...nameMap.keys()], {
     mode: "search",
   });
 

packages/cli/src/lib/formatters/json.ts

@@ -221,7 +221,7 @@ export function parseFieldsList(input: string): string[] {
   const { parse } = _require(
     "../../generated/field-list-grammar.js",
   ) as typeof import("../../generated/field-list-grammar.js");
-  return Array.from(new Set(parse(input)));
+  return [...new Set(parse(input))];
 }
 
 /**

packages/cli/src/lib/formatters/pixel-canvas.ts

@@ -216,7 +216,8 @@ function* normalizeBitmapText(text: string): Iterable<string> {
       .replace(COMBINING_MARK_RE, "");
     if (
       decomposed.length > 0 &&
-      Array.from(decomposed).every((candidate) => hasSpleenGlyph(candidate))
+      // oxlint-disable-next-line typescript/no-misused-spread -- glyphs are looked up per code point
+      [...decomposed].every((candidate) => hasSpleenGlyph(candidate))
     ) {
       yield* decomposed;
       continue;

packages/cli/src/lib/hex-id-recovery.ts

@@ -445,7 +445,7 @@ export type FuzzyLookupAdapter = (ctx: LookupContext) => Promise<string[]>;
 
 /** Deduplicate while preserving order, then filter by prefix + suffix. */
 function filterByCandidate(ids: string[], candidate: HexCandidate): string[] {
-  const unique = Array.from(new Set(ids));
+  const unique = [...new Set(ids)];
   return unique.filter(
     (id) =>
       id.startsWith(candidate.prefix) &&

packages/cli/src/lib/init/clack-utils.ts

@@ -124,7 +124,7 @@ const FEATURE_DISPLAY_ORDER = [
 
 /** Sort features into the canonical order used by summaries and final output. */
 export function sortFeatures(features: string[]): string[] {
-  return features.slice().sort((a, b) => {
+  return [...features].sort((a, b) => {
     const ai = FEATURE_DISPLAY_ORDER.indexOf(a);
     const bi = FEATURE_DISPLAY_ORDER.indexOf(b);
     return (

packages/cli/src/lib/init/interactive.ts

@@ -56,7 +56,7 @@ const FEATURE_SELECTION_CONTEXT =
   "Based on your project, these features are available to set up.";
 
 function sortFeatureOptions(features: string[]): string[] {
-  return features.slice().sort((a, b) => {
+  return [...features].sort((a, b) => {
     const rankDifference =
       (DEFAULT_FEATURE_RANK.get(a) ?? Number.MAX_SAFE_INTEGER) -
       (DEFAULT_FEATURE_RANK.get(b) ?? Number.MAX_SAFE_INTEGER);

packages/cli/src/lib/init/wizard-runner.ts

@@ -452,7 +452,7 @@ async function handleSuspendedStep(
       "done",
     ]);
     const history = stepHistory.get(stepId) ?? [];
-    const previousPhases = history.slice();
+    const previousPhases = [...history];
     history.push(summarizeToolPhaseForHistory(payload, phase, toolResult));
     stepHistory.set(stepId, history);
 

packages/cli/src/lib/metrics-transform.ts

@@ -56,9 +56,9 @@ export function resolveMetricField(
 
   const match = metrics.find((m) => m.name === metricName);
   if (!match) {
-    const candidateNames = Array.from(
-      new Set(metrics.map((m) => m.name).filter((n) => n.length > 0)),
-    );
+    const candidateNames = [
+      ...new Set(metrics.map((m) => m.name).filter((n) => n.length > 0)),
+    ];
     const suggestions = fuzzyMatch(metricName, candidateNames, {
       maxResults: 5,
     });

packages/cli/src/lib/resolve-target.ts

@@ -799,7 +799,7 @@ async function findSimilarProjectsAcrossOrgs(
 
     // Deduplicate slugs so fuzzyMatch doesn't waste slots on the same
     // project appearing in multiple orgs.
-    const uniqueSlugs = Array.from(new Set(allProjects.map((p) => p.slug)));
+    const uniqueSlugs = [...new Set(allProjects.map((p) => p.slug))];
     const slugMatches = fuzzyMatch(slug, uniqueSlugs, { maxResults: 5 });
 
     // When a display name is provided (input contained spaces), also
@@ -816,7 +816,7 @@ async function findSimilarProjectsAcrossOrgs(
           nameToSlug.set(p.name, p.slug);
         }
       }
-      const uniqueNames = Array.from(nameToSlug.keys());
+      const uniqueNames = [...nameToSlug.keys()];
       const matchedNames = fuzzyMatch(displayName, uniqueNames, {
         maxResults: 5,
       });
@@ -826,9 +826,7 @@ async function findSimilarProjectsAcrossOrgs(
     }
 
     // Merge slug matches and name matches, preferring slug matches.
-    const mergedSlugs = Array.from(
-      new Set(slugMatches.concat(nameMatchedSlugs)),
-    );
+    const mergedSlugs = [...new Set([...slugMatches, ...nameMatchedSlugs])];
 
     // Expand matched slugs back to org-qualified entries (may include
     // the same slug from multiple orgs — that's correct for suggestions).

packages/cli/test/lib/api/infrastructure.test.ts

@@ -778,11 +778,11 @@ describe("rawApiRequest binary handling", () => {
     expect(result.status).toBe(200);
     expect(result.body).toBeInstanceOf(Uint8Array);
     const body = result.body as Uint8Array;
-    expect(Array.from(body.slice(0, 8))).toEqual([
+    expect([...body.subarray(0, 8)]).toEqual([
       0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a,
     ]);
     // Must NOT contain the UTF-8 replacement sequence EF BF BD
-    expect(Array.from(body.slice(0, 3))).not.toEqual([0xef, 0xbf, 0xbd]);
+    expect([...body.subarray(0, 3)]).not.toEqual([0xef, 0xbf, 0xbd]);
     expect(body).toEqual(pngBytes);
   });
 

packages/cli/test/lib/db/sqlite.test.ts

@@ -169,7 +169,7 @@ describe.each(DRIVERS)("sqlite adapter [%s driver]", (kind) => {
     const row = db.query("SELECT data FROM t").get() as {
       data: Uint8Array;
     };
-    expect(Array.from(row.data)).toEqual([1, 2, 3, 255]);
+    expect([...row.data]).toEqual([1, 2, 3, 255]);
     db.close();
   });
 

packages/cli/test/lib/delta-upgrade.mocked.test.ts

@@ -74,7 +74,8 @@ function mockFetch(
 const BINARY_NAME = getPlatformBinaryName();
 
 function versionHex(version: string): string {
-  return Array.from(version)
+  return version
+    .split("")
     .map((c) => c.charCodeAt(0).toString(16).padStart(2, "0"))
     .join("");
 }

packages/cli/test/lib/delta-upgrade.test.ts

@@ -219,7 +219,8 @@ describe("extractStableChain", () => {
    * Converts each char to its hex code to produce valid [0-9a-f]+ output.
    */
   function versionToHex(version: string): string {
-    return Array.from(version)
+    return version
+      .split("")
       .map((c) => c.charCodeAt(0).toString(16).padStart(2, "0"))
       .join("");
   }
@@ -943,7 +944,8 @@ describe("resolveStableChain", () => {
    * Reuses the same approach as the extractStableChain tests above.
    */
   function versionHex(version: string): string {
-    return Array.from(version)
+    return version
+      .split("")
       .map((c) => c.charCodeAt(0).toString(16).padStart(2, "0"))
       .join("");
   }

packages/cli/test/lib/dsn/code-scanner.property.test.ts

@@ -49,7 +49,7 @@ const contentArb = array(constantFrom(...BENIGN_CHARS), {
 const DSN_RE =
   /https?:\/\/[a-z0-9]+(?::[a-z0-9]+)?@[a-z0-9.-]+(?:\.[a-z]+|:[0-9]+)\/\d+/gi;
 function referenceMatches(content: string): string[] {
-  return Array.from(new Set(Array.from(content.matchAll(DSN_RE), (m) => m[0])));
+  return [...new Set(Array.from(content.matchAll(DSN_RE), (m) => m[0]))];
 }
 
 describe("property: extractDsnsFromContent fast-path invariance", () => {

packages/cli/test/lib/formatters/output.test.ts

@@ -125,7 +125,7 @@ describe("renderCommandOutput", () => {
     render(w, png, config, { json: false });
     expect(w.chunks).toHaveLength(1);
     expect(w.chunks[0]).toBeInstanceOf(Uint8Array);
-    expect(Array.from(w.bytes)).toEqual([
+    expect([...w.bytes]).toEqual([
       0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a,
     ]);
     // No trailing newline added by the text formatter path
@@ -139,7 +139,7 @@ describe("renderCommandOutput", () => {
     };
     const bytes = new Uint8Array([0xff, 0x00, 0x80]);
     render(w, bytes, config, { json: true });
-    expect(Array.from(w.bytes)).toEqual([0xff, 0x00, 0x80]);
+    expect([...w.bytes]).toEqual([0xff, 0x00, 0x80]);
   });
 
   test("jsonExclude strips fields from JSON output", () => {

packages/cli/test/lib/help.test.ts

@@ -24,7 +24,8 @@ function maxLineWidth(banner: string): number {
     0,
     ...stripAnsi(banner)
       .split("\n")
-      .map((line) => Array.from(line).length),
+      // oxlint-disable-next-line typescript/no-misused-spread -- width is measured in code points
+      .map((line) => [...line].length),
   );
 }
 

packages/cli/test/lib/init/ui/wizard-store.test.ts

@@ -24,9 +24,9 @@ describe("WizardStore step progress", () => {
   test("pre-populates the checklist from CHECKLIST_VISIBLE_STEPS", () => {
     const store = new WizardStore();
     const snapshot = store.getSnapshot();
-    expect(snapshot.steps.map((entry) => entry.id)).toEqual(
-      CHECKLIST_VISIBLE_STEPS.slice(),
-    );
+    expect(snapshot.steps.map((entry) => entry.id)).toEqual([
+      ...CHECKLIST_VISIBLE_STEPS,
+    ]);
     expect(snapshot.steps.every((entry) => entry.status === "pending")).toBe(
       true,
     );

packages/cli/test/lib/sdk-invoke.test.ts

@@ -237,7 +237,7 @@ describe("parseOutput: binary output", () => {
     ]);
     const result = parseOutput<Uint8Array>(undefined, [png]);
     expect(result).toBeInstanceOf(Uint8Array);
-    expect(Array.from(result)).toEqual([
+    expect([...result]).toEqual([
       0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a,
     ]);
   });
@@ -247,7 +247,7 @@ describe("parseOutput: binary output", () => {
       "AB",
       new Uint8Array([0x00, 0xff]),
     ]);
-    expect(Array.from(result)).toEqual([0x41, 0x42, 0x00, 0xff]);
+    expect([...result]).toEqual([0x41, 0x42, 0x00, 0xff]);
   });
 
   test("still JSON-parses textual chunks", () => {