fix(qa-lab): build evidence model before sending /api/evidence success headers

RomneyDa · RomneyDa · commit 911a2aafba4d · 2026-06-18T06:38:12.000-07:00
diff --git a/extensions/qa-lab/src/lab-server.test.ts b/extensions/qa-lab/src/lab-server.test.ts
@@ -518,6 +518,14 @@ describe("qa-lab server", () => {
       },
     });
 
+    // A missing evidence path must return a controlled JSON error, not a reset connection
+    // (the model must build before any success header is written).
+    const missingEvidenceUrl = new URL("/api/evidence", lab.baseUrl);
+    missingEvidenceUrl.searchParams.set("path", ".artifacts/qa-e2e/server/does-not-exist.json");
+    const missingEvidenceResponse = await fetchWithRetry(missingEvidenceUrl.toString());
+    expect(missingEvidenceResponse.status).toBe(404);
+    expect(await missingEvidenceResponse.text()).not.toBe("");
+
     const artifactUrl = new URL("/api/evidence/artifact", lab.baseUrl);
     artifactUrl.searchParams.set("evidencePath", ".artifacts/qa-e2e/server/qa-evidence.json");
     artifactUrl.searchParams.set("artifactPath", "artifact.log");
diff --git a/extensions/qa-lab/src/lab-server.ts b/extensions/qa-lab/src/lab-server.ts
@@ -439,18 +439,15 @@ export async function startQaLabServer(
             res.end(JSON.stringify({ evidence: null }));
             return;
           }
+          // Build the model before sending any headers so a thrown QaEvidenceGalleryError
+          // still routes through writeQaLabServerError (writing headers first would make the
+          // error response throw ERR_HTTP_HEADERS_SENT and reset the connection).
+          const evidence = await buildQaEvidenceGalleryModel({ evidencePath, repoRoot });
           res.writeHead(200, {
             "content-type": "application/json; charset=utf-8",
             "cache-control": "no-store",
           });
-          res.end(
-            JSON.stringify({
-              evidence: await buildQaEvidenceGalleryModel({
-                evidencePath,
-                repoRoot,
-              }),
-            }),
-          );
+          res.end(JSON.stringify({ evidence }));
           return;
         }
         if (
