test: var to const/let; equal to strictEqual

[onlyurei]

Checklist

• make -j8 test (UNIX), or vcbuild test nosign (Windows) passes
• commit message follows commit guidelines

Affected core subsystem(s)

Description of change

test/parallel/test-fs-append-files.js

• var -> const / let
• assert.equal -> assert.strictEqual

[mscdex]

There should be a space after test: in the first line of the commit message.

[onlyurei]

@mscdex fixed.

[Trott]

CI failure is unrelated.

[Trott]

Looks like someone else came along and did these exact same changes in #10110 about 3 days later. Sorry about that @onlyurei!

However! If you still want to get some improvements in to this file, you can try again with a new pull request. One thing I notice is that there are a bunch of unnecessary fs.unlinkSync() calls at the end of the file. They are there to clean up temp files, but tests that use the temp directory remove it and recreate it so there's no need for tests to clean up that way.

Just making that change would be enough for a pull request. If you want to do something a little more involved (or if you want a good second commit after that one lands), all the ncallbacks stuff can be replaced with wrapping of callbacks in common.mustCall().

In the meantime, I'm going to close this pull request. Sorry it didn't land! Thanks for doing it, though!