fix(runner): validate `config.tsconfig` (#34849)

packages/playwright/src/common/configLoader.ts

@@ -254,6 +254,13 @@ function validateConfig(file: string, config: Config) {
     else if (typeof config.workers === 'string' && !config.workers.endsWith('%'))
       throw errorWithFile(file, `config.workers must be a number or percentage`);
   }
+
+  if ('tsconfig' in config && config.tsconfig !== undefined) {
+    if (typeof config.tsconfig !== 'string')
+      throw errorWithFile(file, `config.tsconfig must be a string`);
+    if (!fs.existsSync(path.resolve(file, '..', config.tsconfig)))
+      throw errorWithFile(file, `config.tsconfig does not exist`);
+  }
 }
 
 function validateProject(file: string, project: Project, title: string) {

packages/playwright/src/program.ts

@@ -337,6 +337,9 @@ function overridesFromOptions(options: { [key: string]: any }): ConfigCLIOverrid
     overrides.use = overrides.use || {};
     overrides.use.trace = options.trace;
   }
+  if (overrides.tsconfig && !fs.existsSync(overrides.tsconfig))
+    throw new Error(`--tsconfig "${options.tsconfig}" does not exist`);
+
   return overrides;
 }
 

tests/playwright-test/config.spec.ts

@@ -698,3 +698,35 @@ test('should merge ct configs', async ({ runInlineTest }) => {
   });
   expect(result.exitCode).toBe(0);
 });
+
+test('should throw on invalid config.tsconfig option', async ({ runInlineTest }) => {
+  const result = await runInlineTest({
+    'playwright.config.ts': `
+      export default {
+        tsconfig: true,
+      };
+    `,
+  });
+
+  expect(result.exitCode).toBe(1);
+  expect(result.output).toContain(`config.tsconfig must be a string`);
+});
+
+test('should throw on nonexistant config.tsconfig', async ({ runInlineTest }) => {
+  const result = await runInlineTest({
+    'playwright.config.ts': `
+      export default {
+        tsconfig: './does-not-exist.json',
+      };
+    `,
+  });
+
+  expect(result.exitCode).toBe(1);
+  expect(result.output).toContain(`config.tsconfig does not exist`);
+});
+
+test('should throw on invalid --tsconfig', async ({ runInlineTest }) => {
+  const result = await runInlineTest({}, { 'tsconfig': 'does-not-exist.json' });
+  expect(result.exitCode).toBe(1);
+  expect(result.output).toContain(`--tsconfig "does-not-exist.json" does not exist`);
+});