fix(cli): a killed browser on a busy Windows machine no longer fails check (#5607)

packages/cli/src/browser/launch.test.ts

@@ -0,0 +1,30 @@
+import { spawn } from "node:child_process";
+import { EventEmitter, once } from "node:events";
+import type { Browser } from "puppeteer-core";
+import { describe, expect, it } from "vitest";
+import { closeManagedBrowser } from "./launch.js";
+
+/** A browser whose close never finishes and whose process never reports 'exit', like a loaded Windows host. */
+function silentBrowser(pid: number): Browser {
+  const child = Object.assign(new EventEmitter(), {
+    pid,
+    exitCode: null,
+    signalCode: null,
+    kill: () => true,
+  });
+  return { process: () => child, close: () => new Promise(() => {}) } as unknown as Browser;
+}
+
+describe("closing a killed browser", () => {
+  it("finishes once the OS reports the process gone, before Node reports its exit", async () => {
+    const gone = spawn(process.execPath, ["-e", ""]);
+    await once(gone, "exit");
+    await expect(closeManagedBrowser(silentBrowser(gone.pid!))).resolves.toBeUndefined();
+  });
+
+  it("still fails when the process is alive after the forced shutdown", async () => {
+    await expect(closeManagedBrowser(silentBrowser(process.pid))).rejects.toThrow(
+      "Browser process did not exit after forced shutdown.",
+    );
+  });
+});

packages/cli/src/browser/launch.ts

@@ -6,6 +6,7 @@ import {
 } from "./gpuPolicy.js";
 import { normalizeErrorMessage } from "../utils/errorMessage.js";
 import { requestCliExit } from "../utils/commandResult.js";
+import { processIsAlive } from "../utils/processTree.js";
 
 export class BrowserCleanupError extends AggregateError {}
 
@@ -13,6 +14,7 @@ const browsers = new Set<Browser>();
 const closing = new WeakMap<Browser, Promise<void>>();
 const pending = new Map<Promise<Browser>, AbortController>();
 const CLOSE_GRACE_MS = 1_000;
+const EXIT_POLL_MS = 50;
 let listening = false;
 let shutdown: Promise<void> | undefined;
 
@@ -125,6 +127,7 @@ async function closeBrowser(browser: Browser): Promise<void> {
   if (child.exitCode !== null || child.signalCode !== null) return;
   const exited = new Promise<void>((resolve) => child.once("exit", () => resolve()));
   let timer: NodeJS.Timeout | undefined;
+  let poll: NodeJS.Timeout | undefined;
   const grace = new Promise<void>((resolve) => {
     timer = setTimeout(resolve, CLOSE_GRACE_MS);
   });
@@ -141,8 +144,14 @@ async function closeBrowser(browser: Browser): Promise<void> {
         CLOSE_GRACE_MS,
       );
     });
-    await Promise.race([exited, exitLimit]);
+    const goneBeforeExitEvent = new Promise<void>((resolve) => {
+      poll = setInterval(() => {
+        if (child.pid === undefined || !processIsAlive(child.pid)) resolve();
+      }, EXIT_POLL_MS);
+    });
+    await Promise.race([exited, goneBeforeExitEvent, exitLimit]);
   } finally {
     clearTimeout(timer);
+    clearInterval(poll);
   }
 }