test(cli): a force-closed browser leaves no Chrome process alive on Windows

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

@@ -0,0 +1,53 @@
+import { execFileSync } from "node:child_process";
+import puppeteer, { type Browser } from "puppeteer-core";
+import { expect, it } from "vitest";
+import { launchManagedBrowser } from "./launch.js";
+import { ensureBrowser } from "./manager.js";
+import { processIsAlive } from "../utils/processTree.js";
+
+function directChildren(pid: number): number[] {
+  const out = execFileSync(
+    "powershell.exe",
+    [
+      "-NoProfile",
+      "-NonInteractive",
+      "-Command",
+      `Get-CimInstance Win32_Process -Filter "ParentProcessId=${pid}" | ForEach-Object { $_.ProcessId }`,
+    ],
+    { encoding: "utf8", windowsHide: true },
+  );
+  return out
+    .split(/\r?\n/)
+    .map(Number)
+    .filter((child) => Number.isInteger(child) && child > 0);
+}
+
+// A browser whose graceful close never answers is ended by force; its renderer and GPU processes must go too.
+it.skipIf(process.platform !== "win32")(
+  "a force-closed browser leaves none of its Chrome processes alive",
+  async () => {
+    const { executablePath } = await ensureBrowser();
+    const hanging = {
+      launch: async (options: Parameters<typeof puppeteer.launch>[0]) => {
+        const browser = await puppeteer.launch(options);
+        browser.close = () => new Promise<void>(() => {});
+        return browser;
+      },
+    } as unknown as typeof puppeteer;
+    const launched: Browser = await launchManagedBrowser(hanging, {
+      executablePath,
+      headless: true,
+    });
+    const page = await launched.newPage();
+    await page.goto("about:blank");
+    const root = launched.process()?.pid;
+    expect(root).toBeDefined();
+    const children = directChildren(root!);
+    expect(children.length).toBeGreaterThan(0);
+
+    await launched.close();
+
+    expect(children.filter(processIsAlive)).toEqual([]);
+  },
+  90_000,
+);