cherry-pick(#30312): fix(ui-mode): do not loose run information after writing into testDir (#30328)

Partially reverts #30008
that started to reset all test results upon listing tests, including the
test that did just run and triggered re-listing.

#30300.

Author: mxschmitt

packages/playwright/src/isomorphic/teleReceiver.ts

@@ -130,6 +130,7 @@ type TeleReporterReceiverOptions = {
 };
 
 export class TeleReporterReceiver {
+  public isListing = false;
   private _rootSuite: TeleSuite;
   private _options: TeleReporterReceiverOptions;
   private _reporter: Partial<ReporterV2>;
@@ -143,12 +144,6 @@ export class TeleReporterReceiver {
     this._reporter = reporter;
   }
 
-  reset() {
-    this._rootSuite.suites = [];
-    this._rootSuite.tests = [];
-    this._tests.clear();
-  }
-
   dispatch(message: JsonEvent): Promise<void> | void {
     const { method, params } = message;
     if (method === 'onConfigure') {
@@ -209,6 +204,28 @@ export class TeleReporterReceiver {
     // Always update project in watch mode.
     projectSuite._project = this._parseProject(project);
     this._mergeSuitesInto(project.suites, projectSuite);
+
+    // Remove deleted tests when listing. Empty suites will be auto-filtered
+    // in the UI layer.
+    if (this.isListing) {
+      const testIds = new Set<string>();
+      const collectIds = (suite: JsonSuite) => {
+        suite.tests.map(t => t.testId).forEach(testId => testIds.add(testId));
+        suite.suites.forEach(collectIds);
+      };
+      project.suites.forEach(collectIds);
+
+      const filterTests = (suite: TeleSuite) => {
+        suite.tests = suite.tests.filter(t => {
+          if (testIds.has(t.id))
+            return true;
+          this._tests.delete(t.id);
+          return false;
+        });
+        suite.suites.forEach(filterTests);
+      };
+      filterTests(projectSuite);
+    }
   }
 
   private _onBegin() {

packages/trace-viewer/src/ui/teleSuiteUpdater.ts

@@ -123,9 +123,10 @@ export class TeleSuiteUpdater {
   }
 
   processListReport(report: any[]) {
-    this._receiver.reset();
+    this._receiver.isListing = true;
     for (const message of report)
       this._receiver.dispatch(message);
+    this._receiver.isListing = false;
   }
 
   processTestReportEvent(message: any) {

tests/playwright-test/ui-mode-test-update.spec.ts

@@ -129,6 +129,36 @@ test('should pick new / deleted tests', async ({ runUITest, writeFiles, deleteFi
   `);
 });
 
+test('should not loose run information after execution if test wrote into testDir', async ({ runUITest, writeFiles, deleteFile }) => {
+  test.info().annotations.push({ type: 'issue', description: 'https://github.com/microsoft/playwright/issues/30300' });
+  const { page } = await runUITest({
+    'a.test.ts': `
+      import fs from 'fs';
+      import path from 'path';
+      import { test, expect } from '@playwright/test';
+      test('passes', () => {
+        fs.writeFileSync(path.join(test.info().project.testDir, 'something.txt'), 'hi');
+      });
+    `,
+  });
+  await expect.poll(dumpTestTree(page)).toBe(`
+    ▼ ◯ a.test.ts
+        ◯ passes
+  `);
+  await page.getByTitle('passes').click();
+  await page.getByTitle('Run all').click();
+  await page.waitForTimeout(5_000);
+  await expect(page.getByText('Did not run')).toBeHidden();
+  const listItem = page.getByTestId('actions-tree').getByRole('listitem');
+  await expect(
+      listItem,
+      'action list'
+  ).toHaveText([
+    /Before Hooks[\d.]+m?s/,
+    /After Hooks[\d.]+m?s/,
+  ]);
+});
+
 test('should pick new / deleted nested tests', async ({ runUITest, writeFiles, deleteFile }) => {
   const { page } = await runUITest(basicTestTree);
   await expect.poll(dumpTestTree(page)).toContain(`