Support Images and PDFs (#447)

packages/server/src/__mocks__/fs/promises.ts

@@ -0,0 +1,48 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { vi } from 'vitest';
+import * as actualFsPromises from 'node:fs/promises';
+
+const readFileMock = vi.fn();
+
+// Export a control object so tests can access and manipulate the mock
+export const mockControl = {
+  mockReadFile: readFileMock,
+};
+
+// Export all other functions from the actual fs/promises module
+export const {
+  access,
+  appendFile,
+  chmod,
+  chown,
+  copyFile,
+  cp,
+  lchmod,
+  lchown,
+  link,
+  lstat,
+  mkdir,
+  open,
+  opendir,
+  readdir,
+  readlink,
+  realpath,
+  rename,
+  rmdir,
+  rm,
+  stat,
+  symlink,
+  truncate,
+  unlink,
+  utimes,
+  watch,
+  writeFile,
+} = actualFsPromises;
+
+// Override readFile with our mock
+export const readFile = readFileMock;