test(electron): add unit tests for updater (#5439)

packages/frontend/electron/test/main/mocks/updater.ts

@@ -0,0 +1,37 @@
+import 'electron-updater'; // Prevent BaseUpdater is undefined.
+
+import { type AllPublishOptions, UUID } from 'builder-util-runtime';
+import { randomBytes } from 'crypto';
+import type { AppAdapter } from 'electron-updater/out/AppAdapter';
+import type { DownloadUpdateOptions } from 'electron-updater/out/AppUpdater';
+import type { InstallOptions } from 'electron-updater/out/BaseUpdater';
+import { BaseUpdater } from 'electron-updater/out/BaseUpdater';
+
+import { MockedHttpExecutor } from './http-executor';
+
+/**
+ * For testing, like:
+ * https://github.com/electron-userland/electron-builder/blob/master/packages/electron-updater/src/MacUpdater.ts
+ */
+export class MockedUpdater extends BaseUpdater {
+  httpExecutor: MockedHttpExecutor;
+
+  constructor(options?: AllPublishOptions | null, app?: AppAdapter) {
+    super(options, app);
+
+    this.httpExecutor = new MockedHttpExecutor();
+    Object.assign(this, {
+      getOrCreateStagingUserId: () => {
+        const id = UUID.v5(randomBytes(4096), UUID.OID);
+        return id;
+      },
+    });
+  }
+
+  doInstall(_options: InstallOptions) {
+    return true;
+  }
+  doDownloadUpdate(_options: DownloadUpdateOptions): Promise<string[]> {
+    return Promise.resolve([]);
+  }
+}