[BUG] Setting the use.trace option to `undefined` causes TypeError: Cannot read property 'mode' of undefined

[JCMais]

Context:

• Playwright Version: 1.22.2
• Operating System: Windows
• Node.js version: 14.18
• Browser: All

Code Snippet

Test file

// tests/example.test.ts
import { test } from '@playwright/test'


test('test', async () => {})

Playwright Config

// playwright.config.ts
import { PlaywrightTestConfig } from "@playwright/test";

const playwrightTestConfig: PlaywrightTestConfig = {
  use: {
    trace: undefined,
  },
};

export default playwrightTestConfig;

Describe the bug

Running the above throws this error:

Running 1 test using 1 worker

  ✘  test/example.test.ts:4:1 › test (4ms)


  1) test/example.test.ts:4:1 › test ==================================================================

    TypeError: Cannot read property 'mode' of undefined




  1 failed
    test/example.test.ts:4:1 › test ===================================================================

This is caused by having use,trace as undefined in the playwright config.

This used to work with Playwright v1.19, and given the types of the option (trace?: ...), it should be allowed.

After you figure out what the problem actually is, it is not a big deal as you can simply set the option to off instead of undefined. But it did take me a while to find that the trace option was causing it, as there is no stack trace in the error.

I got this right after upgrading to v1.21, and the reason the option is undefined is that I was setting it conditionally.

[JCMais]

Thanks for fixing it @dgozman!

[dgozman]

The fix was reverted in #15979 due to some breakages, so reopening.