Cleanup throws error if TestCafe if Node.js instance was started with "--watch"

[Klaster1]

What is your Scenario?

I wrote some custom functions for TestCafe and decided to cover these with tests. The test setup consists of a Node.js built-in test runner that spawns TestCafe and asserts against TestCafe JSON reports. As goes with tests, you often want to run them in a watch mode.

What is the Current behavior?

What spawned from execSync, spawn or manually created runner instance (the createTestcafe API) and with the "--watch" flag, TestCafe runs the tests and throws.

TypeError: Cannot read properties of undefined (reading 'resolve')
    at CleanupProcess._onResponse (C:\dev\testcafe-repeat-test\node_modules\testcafe\lib\utils\temp-directory\cleanup-process\index.js:39:37)
    at ChildProcess.<anonymous> (C:\dev\testcafe-repeat-test\node_modules\testcafe\src\utils\temp-directory\cleanup-process\index.js:96:47)
    at ChildProcess.emit (node:events:519:28)
    at ChildProcess.emit (node:domain:488:12)
    at emit (node:internal/child_process:951:14)
    at processTicksAndRejections (node:internal/process/task_queues:83:21)

What is the Expected behavior?

TestCafe runs without throwing errors.

What is your TestCafe test code?

reproducer.zip

Steps to Reproduce

Create a TestCafe runner via the JS API and run an empty TestCafe test with it. When starting the .js, use "--watch" node argument.

TestCafe version

3.6.2

Node.js version

20.15.0

Platform(s) and version(s)

WIndows 11

[Klaster1]

Debugging indicates that this method does not validate the message contents. After I add if (!response.id) return to _onResponse, everything goes back to normal.

How a Node.js watch message payload looks:

{
  'watch:require': [
    'C:\\dev\\testcafe-repeat-test\\node_modules\\testcafe\\lib\\utils\\temp-directory\\cleanup-process\\commands.js'
  ]
}

[github-actions]

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[github-actions]

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[github-actions]

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