fix(electron): allow downloads (#31390)

packages/playwright-core/src/server/browserContext.ts

@@ -654,8 +654,13 @@ export function validateBrowserContextOptions(options: channels.BrowserNewContex
     throw new Error(`"deviceScaleFactor" option is not supported with null "viewport"`);
   if (options.noDefaultViewport && !!options.isMobile)
     throw new Error(`"isMobile" option is not supported with null "viewport"`);
-  if (options.acceptDownloads === undefined)
+  if (options.acceptDownloads === undefined && browserOptions.name !== 'electron')
     options.acceptDownloads = 'accept';
+  // Electron requires explicit acceptDownloads: true since we wait for
+  // https://github.com/electron/electron/pull/41718 to be widely shipped.
+  // In 6-12 months, we can remove this check.
+  else if (options.acceptDownloads === undefined && browserOptions.name === 'electron')
+    options.acceptDownloads = 'internal-browser-default';
   if (!options.viewport && !options.noDefaultViewport)
     options.viewport = { width: 1280, height: 720 };
   if (options.recordVideo) {

packages/playwright-core/src/server/chromium/crBrowser.ts

@@ -348,7 +348,7 @@ export class CRBrowserContext extends BrowserContext {
   override async _initialize() {
     assert(!Array.from(this._browser._crPages.values()).some(page => page._browserContext === this));
     const promises: Promise<any>[] = [super._initialize()];
-    if (this._browser.options.name !== 'electron' && this._browser.options.name !== 'clank' && this._options.acceptDownloads !== 'internal-browser-default') {
+    if (this._browser.options.name !== 'clank' && this._options.acceptDownloads !== 'internal-browser-default') {
       promises.push(this._browser._session.send('Browser.setDownloadBehavior', {
         behavior: this._options.acceptDownloads === 'accept' ? 'allowAndName' : 'deny',
         browserContextId: this._browserContextId,

tests/electron/electron-app.spec.ts

@@ -314,3 +314,27 @@ test('should return app name / version from manifest', async ({ launchElectronAp
     version: '1.0.0'
   });
 });
+
+test('should report downloads', async ({ launchElectronApp, server }) => {
+  test.skip(parseInt(require('electron/package.json').version.split('.')[0], 10) < 30, 'Depends on https://github.com/electron/electron/pull/41718');
+
+  server.setRoute('/download', (req, res) => {
+    res.setHeader('Content-Type', 'application/octet-stream');
+    res.setHeader('Content-Disposition', 'attachment');
+    res.end(`Hello world`);
+  });
+
+  const app = await launchElectronApp('electron-window-app.js', [], {
+    acceptDownloads: true,
+  });
+  const window = await app.firstWindow();
+  await window.setContent(`<a href="${server.PREFIX}/download">download</a>`);
+  const [download] = await Promise.all([
+    window.waitForEvent('download'),
+    window.click('a')
+  ]);
+  const path = await download.path();
+  expect(fs.existsSync(path)).toBeTruthy();
+  expect(fs.readFileSync(path).toString()).toBe('Hello world');
+  await app.close();
+});