What is the problem this feature will solve?

Currently, running node --watch --test some.test.js and then making changes in that test file will result in difficult to recognize output. That is, it's difficult to determine if the output is new when the result hasn't changed.

What is the feature you are proposing to solve the problem?

Whenever watch mode re-runs the script, write out a timestamp as the first line of the output, e.g. console.log(new Date().toISOString()).

What alternatives have you considered?

No response