fix(openapi): unmarshal HTTP responses from raw JSON text

src/codegen/generators/typescript/channels/protocols/http/client.ts

@@ -170,15 +170,20 @@ function generateFunctionImplementation(params: {
     ? `const body = context.payload?.marshal();`
     : `const body = undefined;`;
 
-  // Generate response parsing
-  // Use unmarshalByStatusCode if the payload is a union type with status code support
+  // Generate response parsing.
+  // Use unmarshalByStatusCode if the payload is a union type with status code support.
+  // unmarshal receives the raw JSON text (JSON.stringify(rawData)) rather than the
+  // parsed object: object/array models accept either, but primitive-typed payloads
+  // (e.g. `type X = string`) generate `unmarshal(json: string)` which JSON.parses its
+  // argument, so passing the already-parsed value would both fail to type-check and
+  // throw at runtime.
   let responseParseCode: string;
   if (replyMessageModule) {
     responseParseCode = includesStatusCodes
-      ? `const responseData = ${replyMessageModule}.unmarshalByStatusCode(rawData, response.status);`
-      : `const responseData = ${replyMessageModule}.unmarshal(rawData);`;
+      ? `const responseData = ${replyMessageModule}.unmarshalByStatusCode(JSON.stringify(rawData), response.status);`
+      : `const responseData = ${replyMessageModule}.unmarshal(JSON.stringify(rawData));`;
   } else {
-    responseParseCode = `const responseData = ${replyMessageType}.unmarshal(rawData);`;
+    responseParseCode = `const responseData = ${replyMessageType}.unmarshal(JSON.stringify(rawData));`;
   }
 
   // Generate default context for optional context parameter

test/codegen/generators/typescript/__snapshots__/channels.spec.ts.snap

@@ -1093,7 +1093,7 @@ async function addPet(context: AddPetContext): Promise<HttpClientResponse<Pet>>
 
     // Parse response
     const rawData = await response.json();
-    const responseData = Pet.unmarshal(rawData);
+    const responseData = Pet.unmarshal(JSON.stringify(rawData));
 
     // Extract response metadata
     const responseHeaders = extractHeaders(response);
@@ -1216,7 +1216,7 @@ async function updatePet(context: UpdatePetContext): Promise<HttpClientResponse<
 
     // Parse response
     const rawData = await response.json();
-    const responseData = Pet.unmarshal(rawData);
+    const responseData = Pet.unmarshal(JSON.stringify(rawData));
 
     // Extract response metadata
     const responseHeaders = extractHeaders(response);
@@ -1339,7 +1339,7 @@ async function findPetsByStatusAndCategory(context: FindPetsByStatusAndCategoryC
 
     // Parse response
     const rawData = await response.json();
-    const responseData = FindPetsByStatusAndCategoryResponseModule.unmarshal(rawData);
+    const responseData = FindPetsByStatusAndCategoryResponseModule.unmarshal(JSON.stringify(rawData));
 
     // Extract response metadata
     const responseHeaders = extractHeaders(response);
@@ -3038,7 +3038,7 @@ async function getPingRequest(context: GetPingRequestContext = {}): Promise<Http
 
     // Parse response
     const rawData = await response.json();
-    const responseData = TestPayloadModelModule.unmarshal(rawData);
+    const responseData = TestPayloadModelModule.unmarshal(JSON.stringify(rawData));
 
     // Extract response metadata
     const responseHeaders = extractHeaders(response);

test/codegen/generators/typescript/channels.spec.ts

@@ -622,6 +622,13 @@ describe('channels', () => {
         expect(generatedChannels.files.length).toBeGreaterThan(0);
         expect(generatedChannels.result).toMatchSnapshot('openapi-http_client-index');
         expect(generatedChannels.protocolFiles['http_client']).toMatchSnapshot('openapi-http_client-protocol-code');
+
+        // Responses are unmarshalled from the raw JSON text, not the parsed
+        // object, so primitive-typed payloads whose unmarshal JSON.parses its
+        // argument keep working. See fix/openapi-http-client-primitive-response.
+        const httpProtocolCode = generatedChannels.protocolFiles['http_client'];
+        expect(httpProtocolCode).toContain('unmarshal(JSON.stringify(rawData))');
+        expect(httpProtocolCode).not.toMatch(/unmarshal\(rawData\)/);
       });
 
       it('should skip generation when http_client is not in protocols', async () => {

test/runtime/openapi-primitive.json

@@ -0,0 +1,42 @@
+{
+  "openapi": "3.1.0",
+  "info": {
+    "title": "Primitive Response API",
+    "version": "1.0.0",
+    "description": "Minimal spec whose operations return primitive (non-object) payloads, used to prove the HTTP client unmarshals string/number bodies correctly."
+  },
+  "paths": {
+    "/echo": {
+      "get": {
+        "operationId": "getEcho",
+        "summary": "Return a plain string body",
+        "responses": {
+          "200": {
+            "description": "A plain string",
+            "content": {
+              "application/json": {
+                "schema": { "type": "string" }
+              }
+            }
+          }
+        }
+      }
+    },
+    "/count": {
+      "get": {
+        "operationId": "getCount",
+        "summary": "Return a plain number body",
+        "responses": {
+          "200": {
+            "description": "A plain number",
+            "content": {
+              "application/json": {
+                "schema": { "type": "number" }
+              }
+            }
+          }
+        }
+      }
+    }
+  }
+}

test/runtime/typescript/codegen-openapi-primitive.mjs

@@ -0,0 +1,30 @@
+/** @type {import("../../../dist").TheCodegenConfiguration} **/
+export default {
+	inputType: 'openapi',
+	inputPath: '../openapi-primitive.json',
+	language: 'typescript',
+	generators: [
+		{
+			preset: 'payloads',
+			outputPath: './src/openapi-primitive/payloads',
+			serializationType: 'json',
+		},
+		{
+			preset: 'parameters',
+			outputPath: './src/openapi-primitive/parameters',
+		},
+		{
+			preset: 'headers',
+			outputPath: './src/openapi-primitive/headers',
+		},
+		{
+			preset: 'types',
+			outputPath: './src/openapi-primitive',
+		},
+		{
+			preset: 'channels',
+			outputPath: './src/openapi-primitive/channels',
+			protocols: ['http_client']
+		}
+	]
+};

test/runtime/typescript/package.json

@@ -12,10 +12,11 @@
     "test:websocket": "jest -- ./test/channels/regular/websocket.spec.ts",
     "test:http": "jest -- ./test/channels/request_reply/http_client/",
     "test:payload-types": "jest -- ./test/payload-types/",
-    "generate": "npm run generate:regular && npm run generate:request:reply && npm run generate:openapi && npm run generate:payload-types",
+    "generate": "npm run generate:regular && npm run generate:request:reply && npm run generate:openapi && npm run generate:openapi-primitive && npm run generate:payload-types",
     "generate:request:reply": "cross-env CODEGEN_TELEMETRY_DISABLED=1 node ../../../bin/run.mjs generate ./codegen-request-reply.mjs",
     "generate:regular": "cross-env CODEGEN_TELEMETRY_DISABLED=1 node ../../../bin/run.mjs generate ./codegen-regular.mjs",
     "generate:openapi": "cross-env CODEGEN_TELEMETRY_DISABLED=1 node ../../../bin/run.mjs generate ./codegen-openapi.mjs",
+    "generate:openapi-primitive": "cross-env CODEGEN_TELEMETRY_DISABLED=1 node ../../../bin/run.mjs generate ./codegen-openapi-primitive.mjs",
     "generate:payload-types": "cross-env CODEGEN_TELEMETRY_DISABLED=1 node ../../../bin/run.mjs generate ./codegen-payload-types.mjs",
     "debug:generate": "node --inspect-brk ../../../bin/run.mjs generate"
   },

test/runtime/typescript/src/openapi-primitive/Types.ts

@@ -0,0 +1,26 @@
+export type Paths = '/echo' | '/count';
+export type OperationIds = 'getEcho' | 'getCount';
+export function ToPath(operationId: OperationIds): Paths {
+  switch (operationId) {
+    case 'getEcho':
+    return '/echo';
+  case 'getCount':
+    return '/count';
+    default:
+      throw new Error('Unknown operation ID: ' + operationId);
+  }
+}
+export function ToOperationIds(path: Paths): OperationIds[] {
+  switch (path) {
+    case '/echo':
+    return ['getEcho'];
+  case '/count':
+    return ['getCount'];
+    default:
+      throw new Error('Unknown path: ' + path);
+  }
+}
+export const PathsMap: Record<OperationIds, Paths> = {
+  'getEcho': '/echo',
+  'getCount': '/count'
+};