cherry-pick(#21843): chore(ui): show load errors

packages/playwright-test/src/runner/uiMode.ts

@@ -161,7 +161,8 @@ class UIMode {
     const context: TaskRunnerState = { config: this._config, reporter, phases: [] };
     clearCompilationCache();
     reporter.onConfigure(this._config);
-    await taskRunner.run(context, 0);
+    const status = await taskRunner.run(context, 0);
+    reporter.onExit({ status });
   }
 
   private async _runTests(testIds: string[]) {

packages/trace-viewer/src/ui/watchMode.tsx

@@ -22,7 +22,7 @@ import { TreeView } from '@web/components/treeView';
 import type { TreeState } from '@web/components/treeView';
 import { baseFullConfig, TeleReporterReceiver, TeleSuite } from '@testIsomorphic/teleReceiver';
 import type { TeleTestCase } from '@testIsomorphic/teleReceiver';
-import type { FullConfig, Suite, TestCase, Location } from '../../../playwright-test/types/testReporter';
+import type { FullConfig, Suite, TestCase, Location, TestError } from '../../../playwright-test/types/testReporter';
 import { SplitView } from '@web/components/splitView';
 import { MultiTraceModel } from './modelUtil';
 import './watchMode.css';
@@ -368,8 +368,8 @@ const TestList: React.FC<{
     } else {
       const fileNames = new Set<string>();
       for (const itemId of watchedTreeIds.value) {
-        const treeItem = treeItemMap.get(itemId)!;
-        const fileName = treeItem.location.file;
+        const treeItem = treeItemMap.get(itemId);
+        const fileName = treeItem?.location.file;
         if (fileName)
           fileNames.add(fileName);
       }
@@ -396,8 +396,8 @@ const TestList: React.FC<{
       visit(rootItem);
     } else {
       for (const treeId of watchedTreeIds.value) {
-        const treeItem = treeItemMap.get(treeId)!;
-        const fileName = treeItem.location.file;
+        const treeItem = treeItemMap.get(treeId);
+        const fileName = treeItem?.location.file;
         if (fileName && set.has(fileName))
           testIds.push(...collectTestIds(treeItem));
       }
@@ -577,6 +577,10 @@ const refreshRootSuite = (eraseResults: boolean): Promise<void> => {
         ++progress.passed;
       throttleUpdateRootSuite(config, rootSuite, progress);
     },
+
+    onError: (error: TestError) => {
+      xtermDataSource.write((error.stack || error.value || '') + '\n');
+    },
   });
   return sendMessage('list', {});
 };

packages/web/src/components/xtermWrapper.tsx

@@ -101,7 +101,7 @@ export const XtermWrapper: React.FC<{ source: XtermDataSource }> = ({
       terminal.current.terminal.options.theme = theme === 'dark-mode' ? darkTheme : lightTheme;
   }, [theme]);
 
-  return <div className='xterm-wrapper' style={{ flex: 'auto' }} ref={xtermElement}></div>;
+  return <div data-testid='output' className='xterm-wrapper' style={{ flex: 'auto' }} ref={xtermElement}></div>;
 };
 
 const lightTheme: ITheme = {

tests/playwright-test/ui-mode-load-errors.spec.ts

@@ -0,0 +1,32 @@
+/**
+ * Copyright (c) Microsoft Corporation.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { test, expect } from './ui-mode-fixtures';
+
+test.describe.configure({ mode: 'parallel' });
+
+test('should list tests', async ({ runUITest }) => {
+  const page = await runUITest({
+    'a.test.ts': `
+      import { test, expect } from '@playwright/test';
+      test('syntax error', () => {
+        await 1;
+      });
+    `,
+  });
+  await page.getByTitle('Toggle output').click();
+  await expect(page.getByTestId('output')).toContainText(`Unexpected reserved word 'await'`);
+});