From 62d4c3fe0261c7fad813746f93d617ef07b272b0 Mon Sep 17 00:00:00 2001
From: Dmitry Gozman <dgozman@gmail.com>
Date: Fri, 17 Nov 2023 13:36:50 -0800
Subject: [PATCH] fix(defineConfig): do not add an empty project list to
 project-less configs (#28224)

Otherwise, merging two configs without `projects` property will create a
config with an empty project list, which is semantically different and
always leads to "No tests found".
---
 packages/playwright/src/common/configLoader.ts | 3 +++
 tests/playwright-test/config.spec.ts           | 3 +++
 2 files changed, 6 insertions(+)

diff --git a/packages/playwright/src/common/configLoader.ts b/packages/playwright/src/common/configLoader.ts
index 4d72ed73a0..9d648ed0ea 100644
--- a/packages/playwright/src/common/configLoader.ts
+++ b/packages/playwright/src/common/configLoader.ts
@@ -48,6 +48,9 @@ export const defineConfig = (...configs: any[]) => {
       ]
     };
 
+    if (!result.projects && !config.projects)
+      continue;
+
     const projectOverrides = new Map<string, any>();
     for (const project of config.projects || [])
       projectOverrides.set(project.name, project);
diff --git a/tests/playwright-test/config.spec.ts b/tests/playwright-test/config.spec.ts
index bddbde5f57..fb2f1888d2 100644
--- a/tests/playwright-test/config.spec.ts
+++ b/tests/playwright-test/config.spec.ts
@@ -546,6 +546,9 @@ test('should merge configs', async ({ runInlineTest }) => {
           command: 'echo 123',
         }]
       }));
+
+      // Should not add an empty project list.
+      expect(defineConfig({}, {}).projects).toBeUndefined();
     `,
     'a.test.ts': `
       import { test } from '@playwright/test';