Intercept process.stdout and process.stderr

[SimenB]

Summary

Fixes #6311.

Thoughts very much welcome on the implementation. I'm not particularly happy with it. I chose to keep it as a stream so that people doing something.pipe(process.stdout) in their code didn't break.

Test plan

Tests updated.

[SimenB]

@aaronabramov thoughts?

[SimenB]

In particular, the case reported in #6311 now runs like this:

With --silent:

(is it a bug that silent removes "Ran all test suites matching /test_scheduler.test.js/i."?)

[SimenB]

Seems like it broke colors in error output. Not sure why...

EDIT: isTTY was changed. Copied it over.

It might be a better idea to just replace write? IDK

[SimenB]

@mjesun these fail:

https://github.com/facebook/jest/blob/d1ce3cd0135b5a8b64f84998fd5f36be4afb2bef/packages/jest-util/src/__tests__/create_process_object.test.js#L25-L27

Thoughts? Just check that they're still streams?

[aaronabramov]

i actually tried getting this into Jest a few times a while ago, but i think @cpojer had some strong opinions against it.
this one only affects the worker processes, and not the main, right?

[SimenB]

Depending on how process is injected into it, yes. Right now it's a copy (and I just modify the copy) I think, but that can be changed

[SimenB]

Rebased this, would love to land it

[rickhanlonii]

@cpojer do you have thoughts on this, strong or otherwise?

[cpojer]

I am ok with it but I do want to point out that people have been upset about us re-routing console calls. I think I'm probably in favor of merging this, and adding a cli flag that will disable the re-routing for both console and process.stdout/stderr. That way people can choose which one they prefer.

[SimenB]

Yeah, that's a good idea. Unsure how we can make that happen without messing up when we clear lines to update status etc, but worth looking into

[cpojer]

What's the status of this PR?

[SimenB]

I've forgotten about it 😀 I'd like to get back to it at some point though

[earonesty]

Might want to take a look at: https://github.com/AtakamaLLC/capio

[SimenB]

Just spent almost an hour rebasing this across splitting up jest-util into multiple modules and rewriting to TS 😅 Will try to find the time to look into this soonish

[cpojer]

Ping?