fix(coding): reject mismatched Data Service errors

electron/services/data-service-client.ts

@@ -56,6 +56,22 @@ const CONTEXT_KEYS = new Set([
   'retry_after_seconds',
 ]);
 const CONTEXT_RESOURCES = new Set(['instances', 'collections', 'documents', 'bytes']);
+const ERROR_STATUS_BY_CODE: Readonly<Record<string, number>> = {
+  invalid_cursor: 400,
+  instance_not_found: 404,
+  collection_not_found: 404,
+  document_not_found: 404,
+  cursor_expired: 410,
+  revision_conflict: 409,
+  quota_exceeded: 409,
+  document_too_large: 413,
+  invalid_project_id: 422,
+  invalid_collection_name: 422,
+  invalid_document_id: 422,
+  invalid_document_data: 422,
+  invalid_revision: 422,
+  rate_limited: 429,
+};
 
 type FetchImplementation = typeof fetch;
 type AccessTokenGetter = typeof getValidWorksSquareAccessToken;
@@ -376,6 +392,7 @@ function projectError<T>(payload: unknown, response: Response): DataServiceHostR
   const detail = payload.detail;
   const rawCode = boundedString(detail.code, 64);
   if (!rawCode || !KNOWN_ERROR_CODES.has(rawCode)) return invalidResponse();
+  if (ERROR_STATUS_BY_CODE[rawCode] !== response.status) return invalidResponse();
   if (detail.retryable !== undefined && typeof detail.retryable !== 'boolean') return invalidResponse();
   if (detail.context !== undefined && !isRecord(detail.context)) return invalidResponse();
   const code = rawCode;

tests/unit/data-service-client.test.ts

@@ -202,6 +202,24 @@ describe('DataServiceCloudClient', () => {
     });
   });
 
+  it('rejects a known error code paired with the wrong HTTP status', async () => {
+    const client = new DataServiceCloudClient({
+      fetchImpl: vi.fn<typeof fetch>().mockResolvedValue(
+        jsonResponse({ detail: { code: 'quota_exceeded' } }, { status: 400 }),
+      ),
+      getAccessToken: vi.fn().mockResolvedValue('access-token'),
+    });
+
+    const result = await client.inspect(projectId);
+
+    expect(result).toMatchObject({
+      success: false,
+      status: 502,
+      code: 'upstream_invalid_response',
+      data: null,
+    });
+  });
+
   it('normalizes malformed client errors and all upstream 5xx responses safely', async () => {
     const fetchImpl = vi.fn<typeof fetch>()
       .mockResolvedValueOnce(new Response(null, { status: 404 }))