fix: window.open popups are always resizable (#47540)

fix: window.open popups are always resizable

Closes https://github.com/electron/electron/issues/43591.

Per current WHATWG spec, the `window.open` API should always
create a resizable popup window. This change updates the
`parseFeaturesString` function to ensure that windows opened
with `window.open` are always resizable, regardless of the
`resizable` feature string.

docs/breaking-changes.md

@@ -21,6 +21,23 @@ macOS 11 (Big Sur) is no longer supported by [Chromium](https://chromium-review.
 Older versions of Electron will continue to run on Big Sur, but macOS 12 (Monterey)
 or later will be required to run Electron v38.0.0 and higher.
 
+### Behavior Changed: window.open popups are always resizable
+
+Per current [WHATWG spec](https://html.spec.whatwg.org/multipage/nav-history-apis.html#dom-open-dev), the `window.open` API will now always create a resizable popup window.
+
+To restore previous behavior:
+
+```js
+webContents.setWindowOpenHandler((details) => {
+  return {
+    action: 'allow',
+    overrideBrowserWindowOptions: {
+      resizable: details.features.includes('resizable=yes')
+    }
+  }
+})
+```
+
 ## Planned Breaking API Changes (37.0)
 
 ### Utility Process unhandled rejection behavior change

lib/browser/parse-features-string.ts

@@ -91,6 +91,12 @@ export function parseFeatures (features: string) {
     delete parsed[key];
   }
 
+  // Per spec - https://html.spec.whatwg.org/multipage/nav-history-apis.html#dom-open-dev
+  // windows are always resizable.
+  if (parsed.resizable !== undefined) {
+    delete parsed.resizable;
+  }
+
   if (parsed.left !== undefined) parsed.x = parsed.left;
   if (parsed.top !== undefined) parsed.y = parsed.top;
 

spec/chromium-spec.ts

@@ -1273,6 +1273,16 @@ describe('chromium features', () => {
       });
     }
 
+    it('is always resizable', async () => {
+      const w = new BrowserWindow({ show: false });
+      w.loadFile(path.resolve(__dirname, 'fixtures', 'blank.html'));
+      w.webContents.executeJavaScript(`
+        { b = window.open('about:blank', '', 'resizable=no,show=no'); null }
+      `);
+      const [, popup] = await once(app, 'browser-window-created') as [any, BrowserWindow];
+      expect(popup.isResizable()).to.be.true();
+    });
+
     // FIXME(zcbenz): This test is making the spec runner hang on exit on Windows.
     ifit(process.platform !== 'win32')('disables node integration when it is disabled on the parent window', async () => {
       const windowUrl = url.pathToFileURL(path.join(fixturesPath, 'pages', 'window-opener-no-node-integration.html'));