fix(blob): use reporters from the merge config (#27301)

Fixes https://github.com/microsoft/playwright/issues/27281

packages/playwright/src/isomorphic/teleReceiver.ts

@@ -32,7 +32,7 @@ export type JsonConfig = Pick<FullConfig, 'configFile' | 'globalTimeout' | 'maxF
   listOnly: boolean;
 };
 
-export type MergeReporterConfig = Pick<FullConfig, 'configFile' | 'quiet' | 'reportSlowTests' | 'rootDir' >;
+export type MergeReporterConfig = Pick<FullConfig, 'configFile' | 'quiet' | 'reportSlowTests' | 'rootDir' | 'reporter' >;
 
 export type JsonPattern = {
   s?: string;
@@ -327,6 +327,7 @@ export class TeleReporterReceiver {
       result.rootDir = this._reportConfig.rootDir;
       result.reportSlowTests = this._reportConfig.reportSlowTests;
       result.quiet = this._reportConfig.quiet;
+      result.reporter = [...this._reportConfig.reporter];
     }
     return result;
   }

tests/playwright-test/reporter-blob.spec.ts

@@ -1377,3 +1377,42 @@ function readAllFromStreamAsString(stream: NodeJS.ReadableStream): Promise<strin
     stream.on('end', () => resolve(Buffer.concat(chunks).toString('utf8')));
   });
 }
+
+test('reporter list in the custom config', async ({ runInlineTest, mergeReports }) => {
+  test.info().annotations.push({ type: 'issue', description: 'https://github.com/microsoft/playwright/issues/27281' });
+  const reportDir = test.info().outputPath('blob-report');
+  const files = {
+    'playwright.config.ts': `
+      module.exports = { reporter: 'blob' };
+    `,
+    'a.test.ts': `
+      import { test, expect } from '@playwright/test';
+
+      test('first', async ({}) => {
+      });
+    `,
+    'merged/testReporter.js': `
+      class TestReporter {
+        onBegin(fullConfig, suite) {
+          console.log('reporter', fullConfig.reporter);
+        }
+      }
+
+      module.exports = TestReporter;
+    `,
+    'merged/playwright.config.ts': `
+      module.exports = {
+        retries: 1,
+        reporter: [['./testReporter.js', { myOpt: 1 }]]
+      };
+    `,
+  };
+  await runInlineTest(files);
+
+  const { exitCode, output } = await mergeReports(reportDir, undefined, { additionalArgs: ['--config', test.info().outputPath('merged/playwright.config.ts')] });
+  expect(exitCode).toBe(0);
+
+  const text = stripAnsi(output);
+  expect(text).toContain('testReporter.js');
+  expect(text).toContain('{ myOpt: 1 }');
+});