fs: make FSStatWatcher.start private

[lholmquist]

Similar to #29905

An instance of FSStatWatcher is returned when a user calls fs.watchFile,
which will call the start method. A user can't create an instance
of a FSStatWatcher directly. If the start method is called by a user
it is a noop since the watcher has already started.

ATM, a user could call start on a closed watcher and i believe it would restart it, however, they would need to re-pass the filename and other function parameters. I haven't actually tested that out, though. This is what i see from the code. It would be nice if it acted in a similar fashion to the FSWatch class, and a noop would happen if start was called on a closed watcher, but if this function becomes private, then that wouldn't matter

This method is also undocumented, in fact, the whole "Class" FSStatWatcher seems to be undocumented, although that can be a different issue/PR

This PR makes this method private, and would be a semver-major change, similar to the link issue above

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• tests and/or benchmarks are included
• documentation is changed or added
• commit message follows commit guidelines

[jasnell]

Unfortunately I think this will require a deprecation cycle before it can be made private

[lholmquist]

@jasnell i'm good with whatever, but what is the difference between this PR and the previous PR i did, #29905, where there was no deprecation cycle? Both of these methods happen to be undocumented currently

[jasnell]

That should have included a deprecation also. I hadn't seen it before it landed

[lholmquist]

I see that new deprecation PR, #29989, for the FSWatcher.start. I'll do the same then for this one

[lholmquist]

There seems to be some discussion happening in this issue, #29989 (comment), regarding the needing a deprecation or not, so going to wait to see what happens there before proceeding

[lholmquist]

It looks like the outcome of #29989 (comment) , was that it is prefered to have an alias or stub than a runtime deprecation for this type of thing.

I'm going to update this PR then to do that

[lholmquist]

Updated this PR with the stubbed out start method

[lholmquist]

Also gave this a rebase since it was out of date

[lholmquist]

also adding in a comment, which was suggested here: #30160 (review)

I also realize i have a 2 different PR's open for the same file, sorry about that :)

[lholmquist]

Just did a rebase now that #30160 has been merged

[lholmquist]

@jasnell@addaleax If you have time i would appreciate your feedback.

[addaleax]

Thank you for the ping!

[addaleax]

This needs another @nodejs/tsc approval in order to land

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/26703/

[Trott]

CITGM: https://ci.nodejs.org/view/Node.js-citgm/job/citgm-smoker/2092/

[addaleax]

Landed in 535e957 🎉