test: remove common.noop

[Trott]

This change removes common.noop from the Node.js internal testing
common module.

Over the last few weeks, I've grown to dislike the common.noop
abstraction.

First, new (and experienced) contributors are unaware of it and so it
results in a large number of low-value nits on PRs. It also increases
the number of things newcomers and infrequent contributors have to be
aware of to be effective on the project.

Second, it is confusing. Is it a singleton/property or a getter? Which
should be expected? This can lead to subtle and hard-to-find bugs. (To
my knowledge, none have landed on master. But I also think it's only a
matter of time.)

Third, the abstraction is low-value in my opinion. What does it really
get us? A case could me made that it is without value at all.

Lastly, and this is minor, but the abstraction is wordier than not using
the abstraction. common.noop doesn't save anything over () => {}.

So, I propose removing it.

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• documentation is changed or added
• commit message follows commit guidelines

Affected core subsystem(s)

test

[refack]

I don't remember who said that Function.prototype.call is a built in noop for when you need to refer to it by name (removeListener, etc)

[TimothyGu]

CI: https://ci.nodejs.org/job/node-test-pull-request/7846/

[TimothyGu]

LGTM if CI is green.

[jasnell]

I'm going to abstain on this. I find it useful (which is why I added it :-) ...). I would likely just do it as a revert of the original commit that added it then do a separate commit that adds back in the changes to common.mustCall() defaulting to a no-op.

[lpinca]

Most of the problems caused by common.noop can be avoided by paying a little attention when using it so I'm with @jasnell in the sense that I find it useful but I'm also fine with not using it at all :)

[benjamingr]

Note that I reviewed the changes and the changes LGTM, but I'm +0 on actually removing common.noop.

[Trott]

Rebased to resolve a few conflicts. New CI: https://ci.nodejs.org/job/node-test-pull-request/7907/

[Trott]

Obviously, I"m all for this, but there are more neutral comments than supportive comments. If anyone who hasn't weighed in yet has objections, please comment! Thanks! /cc @nodejs/testing

[thefourtheye]

-0. I kinda liked the idea of common.noop. If we are repeating something in many files, it is better to put it in a common module. Moreover, if we want to use normal functions instead of arrow functions for noop, for whatever reason, again there will be code churn.

[Trott]

CI: https://ci.nodejs.org/job/node-test-pull-request/7981/

[Trott]

CI: https://ci.nodejs.org/job/node-test-pull-request/7982/

[Trott]

Rebased. Another CI: https://ci.nodejs.org/job/node-test-pull-request/7998/

[Trott]

It's time...

CI: https://ci.nodejs.org/job/node-test-pull-request/8939/

[Trott]

Landed in 380929e

[addaleax]

@Trott This doesn’t land cleanly on 8.x; can you backport it? (link to the backport guide)

[Trott]

Backport in #14174

[MylesBorins]

Managed to get this to land on v6.x

this common.noop thing has been a trip, just backported it yesterday 😅