test: improve e2e tests

tests/e2e.spec.ts

@@ -1,7 +1,8 @@
-import type {ElectronApplication} from 'playwright';
+import type {ElectronApplication, JSHandle} from 'playwright';
 import {_electron as electron} from 'playwright';
 import {afterAll, beforeAll, expect, test} from 'vitest';
 import {createHash} from 'crypto';
+import type {BrowserWindow} from 'electron';
 
 let electronApp: ElectronApplication;
 
@@ -14,22 +15,27 @@ afterAll(async () => {
 });
 
 test('Main window state', async () => {
-  const windowState: {isVisible: boolean; isDevToolsOpened: boolean; isCrashed: boolean} =
-    await electronApp.evaluate(({BrowserWindow}) => {
-      const mainWindow = BrowserWindow.getAllWindows()[0];
-
+  const page = await electronApp.firstWindow();
+  const window: JSHandle<BrowserWindow> = await electronApp.browserWindow(page);
+  const windowState = await window.evaluate(
+    (mainWindow): Promise<{isVisible: boolean; isDevToolsOpened: boolean; isCrashed: boolean}> => {
       const getState = () => ({
         isVisible: mainWindow.isVisible(),
         isDevToolsOpened: mainWindow.webContents.isDevToolsOpened(),
         isCrashed: mainWindow.webContents.isCrashed(),
       });
 
       return new Promise(resolve => {
+        /**
+         * The main window is created hidden, and is shown only when it is ready.
+         * See {@link ../packages/main/src/mainWindow.ts} function
+         */
         if (mainWindow.isVisible()) {
           resolve(getState());
-        } else mainWindow.once('ready-to-show', () => setTimeout(() => resolve(getState()), 0));
+        } else mainWindow.once('ready-to-show', () => resolve(getState()));
       });
-    });
+    },
+  );
 
   expect(windowState.isCrashed, 'The app has crashed').toBeFalsy();
   expect(windowState.isVisible, 'The main window was not visible').toBeTruthy();