(v7.x backport) test: refactor test-stream2-readable-wrap.js

[DavidGoussev]

test: refactor test-stream2-readable-wrap.js

implement callback wrapper common.mustCall

remove process.on('exit') with callback wrapper common.mustCall

PR-URL: #11784
Backport-of: #10551

[mscdex]

Diff shows no changes?

[DavidGoussev]

@mscdex @gibfahn Hi all, I cherry-picked my original PR commit hash as specified and I received the following:

git cherry-pick b550a8ce
On branch backport-10551-to-v7.x
You are currently cherry-picking commit b550a8c.

nothing to commit, working directory clean
The previous cherry-pick is now empty, possibly due to conflict resolution.
If you wish to commit it anyway, use:

    git commit --allow-empty

Otherwise, please use 'git reset'

I decided to plow forth with a git commit --allow-empty. Any suggestions?

[mscdex]

It looks like the commit was already landed in v7.x-staging by @italoacasas back on 1/30/2017 (see the history here) and that is why this PR's commit is empty. The commit was included in the v7.5.0 release.

With that in mind, I think this can be closed as there is nothing left to do.

[DavidGoussev]

@mscdex That's great! I saw the work by @italoacasas earlier, but I noticed subsequent messages on the orig PR requesting a backport. At any rate, this has been a great introduction to the how-tos re: backporting!

[mscdex]

It looks like the commit hasn't made its way to v6.x-staging and/or v4.x-staging yet, so it's possible manual backports may be needed for those branches since they do not currently contain the commit and are not currently listed in the current v6.10.1 and v4.8.1 proposal PRs.