fix(cli): select host-compatible cached browser (#2861)

* fix(cli): select host-compatible cached browser

* test(engine): make browser cache fixture portable

* fix(browser): reject foreign ARM cache binaries

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

@@ -130,7 +130,9 @@ function installPuppeteerBrowsersMock(
       executablePath: string;
       path?: string;
       buildId?: string;
+      platform?: string;
     }>;
+    browserPlatform?: string;
     installedInHfCacheError?: Error;
     installResult?: { executablePath: string };
     installImpl?: () => Promise<{ executablePath: string }>;
@@ -138,10 +140,15 @@ function installPuppeteerBrowsersMock(
 ) {
   vi.doMock("@puppeteer/browsers", () => ({
     Browser: { CHROMEHEADLESSSHELL: "chrome-headless-shell" },
-    detectBrowserPlatform: () => "linux",
+    detectBrowserPlatform: () => opts.browserPlatform ?? "linux",
     getInstalledBrowsers: opts.installedInHfCacheError
       ? vi.fn().mockRejectedValue(opts.installedInHfCacheError)
-      : vi.fn().mockResolvedValue(opts.installedInHfCache ?? []),
+      : vi.fn().mockResolvedValue(
+          (opts.installedInHfCache ?? []).map((browser) => ({
+            platform: opts.browserPlatform ?? "linux",
+            ...browser,
+          })),
+        ),
     install: vi
       .fn()
       .mockImplementation(
@@ -222,6 +229,41 @@ describe("findBrowser — cache resolution", () => {
     expect(result).toEqual({ executablePath: SYSTEM_CHROME, source: "system" });
   });
 
+  it("ignores a current-version HyperFrames cache entry for another platform", async () => {
+    Object.defineProperty(process, "platform", { value: "darwin", configurable: true });
+    Object.defineProperty(process, "arch", { value: "arm64", configurable: true });
+    const macArm64Binary = join(
+      HF_CACHE,
+      "chrome-headless-shell",
+      "mac_arm-131.0.6778.85",
+      "chrome-headless-shell-mac-arm64",
+      "chrome-headless-shell",
+    );
+    installFsMocks({ existing: new Set([HF_CACHE, HF_BINARY, macArm64Binary]) });
+    installPuppeteerBrowsersMock({
+      browserPlatform: "mac_arm",
+      installedInHfCache: [
+        {
+          browser: "chrome-headless-shell",
+          executablePath: HF_BINARY,
+          buildId: CHROME_VERSION,
+          platform: "linux",
+        },
+        {
+          browser: "chrome-headless-shell",
+          executablePath: macArm64Binary,
+          buildId: CHROME_VERSION,
+          platform: "mac_arm",
+        },
+      ],
+    });
+
+    const { findBrowser } = await import("./manager.js");
+    const result = await findBrowser();
+
+    expect(result).toEqual({ executablePath: macArm64Binary, source: "cache" });
+  });
+
   it("re-downloads when the hyperframes cache manifest points at a missing binary", async () => {
     const redownloadedBinary = join(
       HF_CACHE,
@@ -492,6 +534,91 @@ describe("findBrowser — cache resolution", () => {
     expect(result).toEqual({ executablePath: PUPPETEER_BINARY, source: "cache" });
   });
 
+  it.each([
+    {
+      hostPlatform: "darwin",
+      hostArch: "arm64",
+      expectedDirectory: "chrome-headless-shell-mac-arm64",
+      expectedExecutable: "chrome-headless-shell",
+    },
+    {
+      hostPlatform: "darwin",
+      hostArch: "x64",
+      expectedDirectory: "chrome-headless-shell-mac-x64",
+      expectedExecutable: "chrome-headless-shell",
+    },
+    {
+      hostPlatform: "linux",
+      hostArch: "x64",
+      expectedDirectory: "chrome-headless-shell-linux64",
+      expectedExecutable: "chrome-headless-shell",
+    },
+    {
+      hostPlatform: "win32",
+      hostArch: "ia32",
+      expectedDirectory: "chrome-headless-shell-win32",
+      expectedExecutable: "chrome-headless-shell.exe",
+    },
+    {
+      hostPlatform: "win32",
+      hostArch: "x64",
+      expectedDirectory: "chrome-headless-shell-win64",
+      expectedExecutable: "chrome-headless-shell.exe",
+    },
+  ])(
+    "selects only the host-compatible cached shell on $hostPlatform/$hostArch when every platform is present",
+    async ({ hostPlatform, hostArch, expectedDirectory, expectedExecutable }) => {
+      Object.defineProperty(process, "platform", { value: hostPlatform, configurable: true });
+      Object.defineProperty(process, "arch", { value: hostArch, configurable: true });
+      const version = "host-148.0.7778.97";
+      const candidates = [
+        ["chrome-headless-shell-linux64", "chrome-headless-shell"],
+        ["chrome-headless-shell-mac-arm64", "chrome-headless-shell"],
+        ["chrome-headless-shell-mac-x64", "chrome-headless-shell"],
+        ["chrome-headless-shell-win32", "chrome-headless-shell.exe"],
+        ["chrome-headless-shell-win64", "chrome-headless-shell.exe"],
+      ] as const;
+      const binaries = candidates.map(([directory, executable]) =>
+        join(PUPPETEER_CACHE, version, directory, executable),
+      );
+      const expectedBinary = join(PUPPETEER_CACHE, version, expectedDirectory, expectedExecutable);
+      installFsMocks({
+        existing: new Set([PUPPETEER_CACHE, ...binaries]),
+        dirs: { [PUPPETEER_CACHE]: [version] },
+      });
+      installPuppeteerBrowsersMock();
+
+      const { findBrowser } = await import("./manager.js");
+      const result = await findBrowser();
+
+      expect(result).toEqual({ executablePath: expectedBinary, source: "cache" });
+    },
+  );
+
+  it.each([
+    { hostPlatform: "linux", hostArch: "arm64" },
+    { hostPlatform: "win32", hostArch: "arm64" },
+  ])(
+    "does not select a foreign cached shell on unsupported $hostPlatform/$hostArch",
+    async ({ hostPlatform, hostArch }) => {
+      Object.defineProperty(process, "platform", { value: hostPlatform, configurable: true });
+      Object.defineProperty(process, "arch", { value: hostArch, configurable: true });
+      const version = "host-148.0.7778.97";
+      const binaries = [
+        join(PUPPETEER_CACHE, version, "chrome-headless-shell-linux64", "chrome-headless-shell"),
+        join(PUPPETEER_CACHE, version, "chrome-headless-shell-win64", "chrome-headless-shell.exe"),
+      ];
+      installFsMocks({
+        existing: new Set([PUPPETEER_CACHE, ...binaries]),
+        dirs: { [PUPPETEER_CACHE]: [version] },
+      });
+      installPuppeteerBrowsersMock();
+
+      const { findBrowser } = await import("./manager.js");
+      await expect(findBrowser()).resolves.toBeUndefined();
+    },
+  );
+
   it("prefers the puppeteer cache over the hyperframes cache when BOTH are populated", async () => {
     // The HF cache is pinned to `CHROME_VERSION` (131-era) which lags upstream
     // by many releases. The engine's `resolveHeadlessShellPath` scans the

packages/cli/src/browser/manager.ts

@@ -282,7 +282,7 @@ function findFromEnv(): BrowserResult | undefined {
  */
 async function findFromHyperframesCache(): Promise<CacheLookupResult> {
   if (!existsSync(CACHE_DIR)) return {};
-  const { Browser, getInstalledBrowsers } = await loadPuppeteerBrowsers();
+  const { Browser, detectBrowserPlatform, getInstalledBrowsers } = await loadPuppeteerBrowsers();
   // A corrupt cache (stub file where a browser dir is expected, malformed
   // metadata) makes getInstalledBrowsers throw. Treat that as "no cached
   // browser" so resolution falls through to system/download instead of
@@ -302,9 +302,14 @@ async function findFromHyperframesCache(): Promise<CacheLookupResult> {
   // an older hyperframes version (this pin has moved 131 → 151 → 152 across
   // releases) must NOT satisfy resolution, or an upgrade silently keeps
   // running whatever build happened to be cached instead of ever fetching
-  // the version this release actually needs (HF#2060 review).
+  // the version this release actually needs (HF#2060 review). Match platform
+  // as well so a shared/migrated cache cannot return a foreign executable.
+  const hostPlatform = detectBrowserPlatform();
   const match = installed.find(
-    (b) => b.browser === Browser.CHROMEHEADLESSSHELL && b.buildId === CHROME_VERSION,
+    (b) =>
+      b.browser === Browser.CHROMEHEADLESSSHELL &&
+      b.buildId === CHROME_VERSION &&
+      b.platform === hostPlatform,
   );
   if (match && existsSync(match.executablePath)) {
     return { result: { executablePath: match.executablePath, source: "cache" } };
@@ -383,8 +388,33 @@ function compareVersionDirsDescending(a: string, b: string): number {
   return 0;
 }
 
+const CACHED_HEADLESS_SHELL_EXECUTABLES: Readonly<
+  Record<string, readonly [directory: string, executable: string]>
+> = {
+  "darwin/arm64": ["chrome-headless-shell-mac-arm64", "chrome-headless-shell"],
+  "darwin/x64": ["chrome-headless-shell-mac-x64", "chrome-headless-shell"],
+  "linux/x64": ["chrome-headless-shell-linux64", "chrome-headless-shell"],
+  "win32/ia32": ["chrome-headless-shell-win32", "chrome-headless-shell.exe"],
+  "win32/x64": ["chrome-headless-shell-win64", "chrome-headless-shell.exe"],
+};
+
+function cachedHeadlessShellExecutable(
+  hostPlatform = process.platform,
+  hostArch = process.arch,
+): readonly [directory: string, executable: string] | undefined {
+  // Chrome for Testing cache entries are host-specific. Resolve exactly one
+  // platform/architecture directory so a foreign binary cannot win by probe order.
+  // Chrome for Testing does not publish Linux ARM64 binaries. Windows ARM64 can
+  // emulate x64 only on supported Windows 11 builds, which this platform/arch-only
+  // resolver cannot prove, so both hosts deliberately fall through to system
+  // browser discovery instead of attempting a potentially foreign cached binary.
+  return CACHED_HEADLESS_SHELL_EXECUTABLES[`${hostPlatform}/${hostArch}`];
+}
+
 function findFromPuppeteerCache(): BrowserResult | undefined {
   if (!existsSync(PUPPETEER_CACHE_DIR)) return undefined;
+  const executable = cachedHeadlessShellExecutable();
+  if (!executable) return undefined;
   let versions: string[];
   try {
     // Numeric semver-style sort, newest first. Lexicographic `.sort().reverse()`
@@ -399,28 +429,11 @@ function findFromPuppeteerCache(): BrowserResult | undefined {
     // Same shape as `resolveHeadlessShellPath` in engine/browserManager.ts —
     // keep them aligned. If puppeteer ever changes the on-disk layout the two
     // need to move together.
-    const candidates = [
+    const binary = join(PUPPETEER_CACHE_DIR, version, ...executable);
-      join(PUPPETEER_CACHE_DIR, version, "chrome-headless-shell-linux64", "chrome-headless-shell"),
-      join(
-        PUPPETEER_CACHE_DIR,
-        version,
-        "chrome-headless-shell-mac-arm64",
-        "chrome-headless-shell",
-      ),
-      join(PUPPETEER_CACHE_DIR, version, "chrome-headless-shell-mac-x64", "chrome-headless-shell"),
-      join(
-        PUPPETEER_CACHE_DIR,
-        version,
-        "chrome-headless-shell-win64",
-        "chrome-headless-shell.exe",
-      ),
-    ];
-    for (const binary of candidates) {
     if (existsSync(binary)) {
       return { executablePath: binary, source: "cache" };
     }
   }
-  }
   return undefined;
 }
 

packages/engine/src/services/browserManager.test.ts

@@ -401,6 +401,127 @@ describe("resolveHeadlessShellPath", () => {
     }
   });
 
+  it.each([
+    {
+      hostPlatform: "darwin",
+      hostArch: "arm64",
+      expectedDirectory: "chrome-headless-shell-mac-arm64",
+      expectedExecutable: "chrome-headless-shell",
+    },
+    {
+      hostPlatform: "darwin",
+      hostArch: "x64",
+      expectedDirectory: "chrome-headless-shell-mac-x64",
+      expectedExecutable: "chrome-headless-shell",
+    },
+    {
+      hostPlatform: "linux",
+      hostArch: "x64",
+      expectedDirectory: "chrome-headless-shell-linux64",
+      expectedExecutable: "chrome-headless-shell",
+    },
+    {
+      hostPlatform: "win32",
+      hostArch: "ia32",
+      expectedDirectory: "chrome-headless-shell-win32",
+      expectedExecutable: "chrome-headless-shell.exe",
+    },
+    {
+      hostPlatform: "win32",
+      hostArch: "x64",
+      expectedDirectory: "chrome-headless-shell-win64",
+      expectedExecutable: "chrome-headless-shell.exe",
+    },
+  ])(
+    "selects only the host-compatible cached shell on $hostPlatform/$hostArch when every platform is present",
+    ({ hostPlatform, hostArch, expectedDirectory, expectedExecutable }) => {
+      const home = mkdtempSync(join(tmpdir(), "hyperframes-engine-browser-platform-"));
+      try {
+        const cacheVersion = join(
+          home,
+          ".cache",
+          "puppeteer",
+          "chrome-headless-shell",
+          "host-152.0.7928.2",
+        );
+        const candidates = [
+          ["chrome-headless-shell-linux64", "chrome-headless-shell"],
+          ["chrome-headless-shell-mac-arm64", "chrome-headless-shell"],
+          ["chrome-headless-shell-mac-x64", "chrome-headless-shell"],
+          ["chrome-headless-shell-win32", "chrome-headless-shell.exe"],
+          ["chrome-headless-shell-win64", "chrome-headless-shell.exe"],
+        ] as const;
+        for (const [directory, executable] of candidates) {
+          const binary = join(cacheVersion, directory, executable);
+          mkdirSync(join(binary, ".."), { recursive: true });
+          writeFileSync(binary, "");
+        }
+        const expectedBinary = join(cacheVersion, expectedDirectory, expectedExecutable);
+
+        const env = { ...process.env, HOME: home, USERPROFILE: home };
+        delete env.PRODUCER_HEADLESS_SHELL_PATH;
+        delete env.HYPERFRAMES_BROWSER_PATH;
+        const moduleUrl = new URL("./browserManager.ts", import.meta.url).href;
+        const stdout = execFileSync(
+          "bun",
+          [
+            "--eval",
+            `Object.defineProperty(process, "platform", { value: ${JSON.stringify(hostPlatform)} }); Object.defineProperty(process, "arch", { value: ${JSON.stringify(hostArch)} }); import(${JSON.stringify(moduleUrl)}).then(({ resolveHeadlessShellPath }) => process.stdout.write(resolveHeadlessShellPath({}) ?? ""))`,
+          ],
+          { encoding: "utf8", env },
+        );
+
+        expect(stdout).toBe(expectedBinary);
+      } finally {
+        rmSync(home, { recursive: true, force: true });
+      }
+    },
+  );
+
+  it.each([
+    { hostPlatform: "linux", hostArch: "arm64" },
+    { hostPlatform: "win32", hostArch: "arm64" },
+  ])(
+    "does not select a foreign cached shell on unsupported $hostPlatform/$hostArch",
+    ({ hostPlatform, hostArch }) => {
+      const home = mkdtempSync(join(tmpdir(), "hyperframes-engine-browser-unsupported-"));
+      try {
+        const cacheVersion = join(
+          home,
+          ".cache",
+          "puppeteer",
+          "chrome-headless-shell",
+          "host-152.0.7928.2",
+        );
+        for (const [directory, executable] of [
+          ["chrome-headless-shell-linux64", "chrome-headless-shell"],
+          ["chrome-headless-shell-win64", "chrome-headless-shell.exe"],
+        ] as const) {
+          const binary = join(cacheVersion, directory, executable);
+          mkdirSync(join(binary, ".."), { recursive: true });
+          writeFileSync(binary, "");
+        }
+
+        const env = { ...process.env, HOME: home, USERPROFILE: home };
+        delete env.PRODUCER_HEADLESS_SHELL_PATH;
+        delete env.HYPERFRAMES_BROWSER_PATH;
+        const moduleUrl = new URL("./browserManager.ts", import.meta.url).href;
+        const stdout = execFileSync(
+          "bun",
+          [
+            "--eval",
+            `Object.defineProperty(process, "platform", { value: ${JSON.stringify(hostPlatform)} }); Object.defineProperty(process, "arch", { value: ${JSON.stringify(hostArch)} }); import(${JSON.stringify(moduleUrl)}).then(({ resolveHeadlessShellPath }) => process.stdout.write(resolveHeadlessShellPath({}) ?? ""))`,
+          ],
+          { encoding: "utf8", env },
+        );
+
+        expect(stdout).toBe("");
+      } finally {
+        rmSync(home, { recursive: true, force: true });
+      }
+    },
+  );
+
   it("reuses chrome-headless-shell from the HyperFrames-managed cache", () => {
     const home = mkdtempSync(join(tmpdir(), "hyperframes-engine-browser-cache-"));
     try {
@@ -429,7 +550,7 @@ describe("resolveHeadlessShellPath", () => {
         "bun",
         [
           "--eval",
-          `import(${JSON.stringify(moduleUrl)}).then(({ resolveHeadlessShellPath }) => process.stdout.write(resolveHeadlessShellPath({}) ?? ""))`,
+          `Object.defineProperty(process, "platform", { value: "linux" }); Object.defineProperty(process, "arch", { value: "x64" }); import(${JSON.stringify(moduleUrl)}).then(({ resolveHeadlessShellPath }) => process.stdout.write(resolveHeadlessShellPath({}) ?? ""))`,
         ],
         { encoding: "utf8", env },
       );

packages/engine/src/services/browserManager.ts

@@ -133,21 +133,39 @@ function compareBrowserVersionsDescending(left: string, right: string): number {
   return 0;
 }
 
+const CACHED_HEADLESS_SHELL_EXECUTABLES: Readonly<
+  Record<string, readonly [directory: string, executable: string]>
+> = {
+  "darwin/arm64": ["chrome-headless-shell-mac-arm64", "chrome-headless-shell"],
+  "darwin/x64": ["chrome-headless-shell-mac-x64", "chrome-headless-shell"],
+  "linux/x64": ["chrome-headless-shell-linux64", "chrome-headless-shell"],
+  "win32/ia32": ["chrome-headless-shell-win32", "chrome-headless-shell.exe"],
+  "win32/x64": ["chrome-headless-shell-win64", "chrome-headless-shell.exe"],
+};
+
+function cachedHeadlessShellExecutable(
+  hostPlatform = process.platform,
+  hostArch = process.arch,
+): readonly [directory: string, executable: string] | undefined {
+  // Chrome for Testing cache entries are host-specific. Resolve exactly one
+  // platform/architecture directory so a foreign binary cannot win by probe order.
+  // Chrome for Testing does not publish Linux ARM64 binaries. Windows ARM64 can
+  // emulate x64 only on supported Windows 11 builds, which this platform/arch-only
+  // resolver cannot prove, so both hosts deliberately fall through to system
+  // browser discovery instead of attempting a potentially foreign cached binary.
+  return CACHED_HEADLESS_SHELL_EXECUTABLES[`${hostPlatform}/${hostArch}`];
+}
+
 function findCachedHeadlessShell(baseDir: string): string | undefined {
   if (!existsSync(baseDir)) return undefined;
+  const executable = cachedHeadlessShellExecutable();
+  if (!executable) return undefined;
   try {
     const versions = readdirSync(baseDir).sort(compareBrowserVersionsDescending);
     for (const version of versions) {
-      const candidates = [
+      const binary = join(baseDir, version, ...executable);
-        join(baseDir, version, "chrome-headless-shell-linux64", "chrome-headless-shell"),
-        join(baseDir, version, "chrome-headless-shell-mac-arm64", "chrome-headless-shell"),
-        join(baseDir, version, "chrome-headless-shell-mac-x64", "chrome-headless-shell"),
-        join(baseDir, version, "chrome-headless-shell-win64", "chrome-headless-shell.exe"),
-      ];
-      for (const binary of candidates) {
       if (existsSync(binary)) return binary;
     }
-    }
   } catch {
     // Ignore unreadable cache directories and continue browser discovery.
   }