feat: replace BrowserView with WebContentsView (#35658)

spec/api-web-contents-view-spec.ts

@@ -1,18 +1,39 @@
-import { closeWindow } from './lib/window-helpers';
+import { closeAllWindows } from './lib/window-helpers';
+import { expect } from 'chai';
 
-import { BaseWindow, WebContentsView } from 'electron/main';
+import { BaseWindow, View, WebContentsView } from 'electron/main';
+import { once } from 'node:events';
 
 describe('WebContentsView', () => {
-  let w: BaseWindow;
+  afterEach(closeAllWindows);
 
-  afterEach(async () => {
-    await closeWindow(w as any);
-    w = null as unknown as BaseWindow;
+  it('can be instantiated with no arguments', () => {
+    // eslint-disable-next-line no-new
+    new WebContentsView();
+  });
+
+  it('can be instantiated with no webPreferences', () => {
+    // eslint-disable-next-line no-new
+    new WebContentsView({});
   });
 
   it('can be used as content view', () => {
-    w = new BaseWindow({ show: false });
-    w.setContentView(new WebContentsView({}));
+    const w = new BaseWindow({ show: false });
+    w.setContentView(new WebContentsView());
+  });
+
+  it('can be removed after a close', async () => {
+    const w = new BaseWindow({ show: false });
+    const v = new View();
+    const wcv = new WebContentsView();
+    w.setContentView(v);
+    v.addChildView(wcv);
+    await wcv.webContents.loadURL('about:blank');
+    const destroyed = once(wcv.webContents, 'destroyed');
+    wcv.webContents.executeJavaScript('window.close()');
+    await destroyed;
+    expect(wcv.webContents.isDestroyed()).to.be.true();
+    v.removeChildView(wcv);
   });
 
   function triggerGCByAllocation () {
@@ -25,7 +46,7 @@ describe('WebContentsView', () => {
 
   it('doesn\'t crash when GCed during allocation', (done) => {
     // eslint-disable-next-line no-new
-    new WebContentsView({});
+    new WebContentsView();
     setTimeout(() => {
       // NB. the crash we're testing for is the lack of a current `v8::Context`
       // when emitting an event in WebContents's destructor. V8 is inconsistent
@@ -38,4 +59,94 @@ describe('WebContentsView', () => {
       done();
     });
   });
+
+  describe('visibilityState', () => {
+    it('is initially hidden', async () => {
+      const v = new WebContentsView();
+      await v.webContents.loadURL('data:text/html,<script>initialVisibility = document.visibilityState</script>');
+      expect(await v.webContents.executeJavaScript('initialVisibility')).to.equal('hidden');
+    });
+
+    it('becomes visibile when attached', async () => {
+      const v = new WebContentsView();
+      await v.webContents.loadURL('about:blank');
+      expect(await v.webContents.executeJavaScript('document.visibilityState')).to.equal('hidden');
+      const p = v.webContents.executeJavaScript('new Promise(resolve => document.addEventListener("visibilitychange", resolve))');
+      // Ensure that the above listener has been registered before we add the
+      // view to the window, or else the visibilitychange event might be
+      // dispatched before the listener is registered.
+      // executeJavaScript calls are sequential so if this one's finished then
+      // the previous one must also have been finished :)
+      await v.webContents.executeJavaScript('undefined');
+      const w = new BaseWindow();
+      w.setContentView(v);
+      await p;
+      expect(await v.webContents.executeJavaScript('document.visibilityState')).to.equal('visible');
+    });
+
+    it('is initially visible if load happens after attach', async () => {
+      const w = new BaseWindow();
+      const v = new WebContentsView();
+      w.contentView = v;
+      await v.webContents.loadURL('data:text/html,<script>initialVisibility = document.visibilityState</script>');
+      expect(await v.webContents.executeJavaScript('initialVisibility')).to.equal('visible');
+    });
+
+    it('becomes hidden when parent window is hidden', async () => {
+      const w = new BaseWindow();
+      const v = new WebContentsView();
+      w.setContentView(v);
+      await v.webContents.loadURL('about:blank');
+      expect(await v.webContents.executeJavaScript('document.visibilityState')).to.equal('visible');
+      const p = v.webContents.executeJavaScript('new Promise(resolve => document.addEventListener("visibilitychange", resolve))');
+      // We have to wait until the listener above is fully registered before hiding the window.
+      // On Windows, the executeJavaScript and the visibilitychange can happen out of order
+      // without this.
+      await v.webContents.executeJavaScript('0');
+      w.hide();
+      await p;
+      expect(await v.webContents.executeJavaScript('document.visibilityState')).to.equal('hidden');
+    });
+
+    it('becomes visible when parent window is shown', async () => {
+      const w = new BaseWindow({ show: false });
+      const v = new WebContentsView();
+      w.setContentView(v);
+      await v.webContents.loadURL('about:blank');
+      expect(await v.webContents.executeJavaScript('document.visibilityState')).to.equal('hidden');
+      const p = v.webContents.executeJavaScript('new Promise(resolve => document.addEventListener("visibilitychange", resolve))');
+      // We have to wait until the listener above is fully registered before hiding the window.
+      // On Windows, the executeJavaScript and the visibilitychange can happen out of order
+      // without this.
+      await v.webContents.executeJavaScript('0');
+      w.show();
+      await p;
+      expect(await v.webContents.executeJavaScript('document.visibilityState')).to.equal('visible');
+    });
+
+    it('does not change when view is moved between two visible windows', async () => {
+      const w = new BaseWindow();
+      const v = new WebContentsView();
+      w.setContentView(v);
+      await v.webContents.loadURL('about:blank');
+      expect(await v.webContents.executeJavaScript('document.visibilityState')).to.equal('visible');
+
+      const p = v.webContents.executeJavaScript('new Promise(resolve => document.addEventListener("visibilitychange", () => resolve(document.visibilityState)))');
+      // Ensure the listener has been registered.
+      await v.webContents.executeJavaScript('undefined');
+      const w2 = new BaseWindow();
+      w2.setContentView(v);
+      // Wait for the visibility state to settle as "visible".
+      // On macOS one visibilitychange event is fired but visibilityState
+      // remains "visible". On Win/Linux, two visibilitychange events are
+      // fired, a "hidden" and a "visible" one. Reconcile these two models
+      // by waiting until at least one event has been fired, and then waiting
+      // until the visibility state settles as "visible".
+      let visibilityState = await p;
+      for (let attempts = 0; visibilityState !== 'visible' && attempts < 10; attempts++) {
+        visibilityState = await v.webContents.executeJavaScript('new Promise(resolve => document.visibilityState === "visible" ? resolve("visible") : document.addEventListener("visibilitychange", () => resolve(document.visibilityState)))');
+      }
+      expect(visibilityState).to.equal('visible');
+    });
+  });
 });