fix(test): stream QA Lab stdout artifacts (#95119)

* fix(test): bound QA Lab stdout artifact reads

* fix(test): scan QA Lab stdout artifacts incrementally

test/e2e/qa-lab/runtime/qa-otel-smoke-runtime.ts

@@ -3,7 +3,7 @@
 import { spawn, spawnSync, type ChildProcess } from "node:child_process";
 import { randomUUID } from "node:crypto";
 import { existsSync } from "node:fs";
-import { mkdir, mkdtemp, readFile, rm, writeFile } from "node:fs/promises";
+import { mkdir, mkdtemp, open, rm, writeFile } from "node:fs/promises";
 import { createServer, type IncomingMessage, type ServerResponse } from "node:http";
 import { Socket } from "node:net";
 import { tmpdir } from "node:os";
@@ -158,6 +158,7 @@ const MAX_STDOUT_DIAGNOSTIC_LINE_BYTES = readPositiveIntegerEnv(
   "OPENCLAW_QA_OTEL_MAX_STDOUT_DIAGNOSTIC_LINE_BYTES",
   512 * 1024,
 );
+const GATEWAY_STDOUT_ARTIFACT_READ_CHUNK_BYTES = 64 * 1024;
 
 function readPositiveIntegerEnv(
   name: string,
@@ -1075,7 +1076,11 @@ async function appendGatewayStdoutArtifactLogs(params: {
     "gateway.stdout.log",
   );
   try {
-    params.capture.append(await readFile(gatewayStdoutPath, "utf8"));
+    await appendUtf8FileToStdoutDiagnosticCapture(
+      gatewayStdoutPath,
+      params.capture,
+      GATEWAY_STDOUT_ARTIFACT_READ_CHUNK_BYTES,
+    );
     params.capture.flush();
   } catch (error) {
     if (!isErrnoCode(error, "ENOENT")) {
@@ -1084,6 +1089,26 @@ async function appendGatewayStdoutArtifactLogs(params: {
   }
 }
 
+async function appendUtf8FileToStdoutDiagnosticCapture(
+  filePath: string,
+  capture: ReturnType<typeof createStdoutDiagnosticLogCapture>,
+  chunkBytes = GATEWAY_STDOUT_ARTIFACT_READ_CHUNK_BYTES,
+): Promise<void> {
+  const file = await open(filePath, "r");
+  try {
+    const buffer = Buffer.alloc(Math.max(1, chunkBytes));
+    for (;;) {
+      const { bytesRead } = await file.read(buffer, 0, buffer.length);
+      if (bytesRead === 0) {
+        break;
+      }
+      capture.append(buffer.subarray(0, bytesRead));
+    }
+  } finally {
+    await file.close();
+  }
+}
+
 async function stopDockerContainer(name: string): Promise<void> {
   await new Promise<void>((resolve) => {
     const child = spawn("docker", ["stop", name], {
@@ -1882,14 +1907,17 @@ async function main() {
 }
 
 export const testing = {
+  appendGatewayStdoutArtifactLogs,
   appendCapturedBodyText,
   assertSmoke,
   createBoundedTextAccumulator,
+  createStdoutDiagnosticLogCapture,
   decodeRequestBody,
   parseArgs,
   parseStdoutDiagnosticLogLine,
   readPositiveIntegerEnv,
   readRequestBody,
+  appendUtf8FileToStdoutDiagnosticCapture,
   startLocalOtlpReceiver,
   startDockerOtelCollector,
   terminateChildTree,

test/e2e/qa-lab/runtime/qa-otel-smoke.e2e.test.ts

@@ -1,7 +1,7 @@
 // QA OTEL Smoke tests cover QA Lab telemetry evidence.
 import { spawn, spawnSync } from "node:child_process";
 import { EventEmitter } from "node:events";
-import { existsSync, mkdirSync, mkdtempSync, rmSync, statSync } from "node:fs";
+import { existsSync, mkdirSync, mkdtempSync, rmSync, statSync, writeFileSync } from "node:fs";
 import { createConnection as createNetConnection } from "node:net";
 import os from "node:os";
 import path from "node:path";
@@ -501,6 +501,65 @@ describe("qa-otel-smoke receiver bounds", () => {
     expect(output.text()).not.toContain("DO_NOT_RETAIN_COLLECTOR_PREFIX");
   });
 
+  it("streams gateway stdout artifact records without requiring them in the tail", async () => {
+    const tempRoot = mkdtempSync(path.join(os.tmpdir(), "openclaw-qa-otel-stdout-stream-"));
+    const logPath = path.join(tempRoot, "gateway.stdout.log");
+    const capture = testing.createStdoutDiagnosticLogCapture();
+    const record = {
+      signal: "openclaw.diagnostic.log",
+      ts: "2026-06-18T00:00:00.000Z",
+      "service.name": "openclaw-qa-lab-otel-smoke",
+      severityText: "INFO",
+      severityNumber: 9,
+      body: "early log",
+      attributes: {},
+    };
+    try {
+      writeFileSync(
+        logPath,
+        `${JSON.stringify(record)}\n${"x".repeat(256 * 1024)}\nGATEWAY_STDOUT_TAIL\n`,
+      );
+
+      await testing.appendUtf8FileToStdoutDiagnosticCapture(logPath, capture);
+      capture.flush();
+
+      expect(capture.records).toEqual([record]);
+      expect(capture.lines).toHaveLength(1);
+    } finally {
+      rmSync(tempRoot, { force: true, recursive: true });
+    }
+  });
+
+  it("keeps gateway stdout artifact fallback parsing bounded", async () => {
+    const tempRoot = mkdtempSync(path.join(os.tmpdir(), "openclaw-qa-otel-stdout-artifact-"));
+    const outputDir = path.join(tempRoot, "output");
+    const artifactDir = path.join(outputDir, "artifacts", "gateway-runtime");
+    const record = {
+      signal: "openclaw.diagnostic.log",
+      ts: "2026-06-18T00:00:00.000Z",
+      "service.name": "openclaw-qa-lab-otel-smoke",
+      severityText: "INFO",
+      severityNumber: 9,
+      body: "tail log",
+      attributes: {},
+    };
+    try {
+      mkdirSync(artifactDir, { recursive: true });
+      writeFileSync(
+        path.join(artifactDir, "gateway.stdout.log"),
+        `${JSON.stringify(record)}\n${"x".repeat(256 * 1024)}\n`,
+      );
+      const capture = testing.createStdoutDiagnosticLogCapture();
+
+      await testing.appendGatewayStdoutArtifactLogs({ capture, outputDir });
+
+      expect(capture.records).toEqual([record]);
+      expect(capture.lines).toHaveLength(1);
+    } finally {
+      rmSync(tempRoot, { force: true, recursive: true });
+    }
+  });
+
   it("times out and kills a wedged QA suite child with a detached gateway", async () => {
     if (process.platform === "win32") {
       return;