PRChecker: support new label fast-track

[priyank-p]

Now core has the label fast-track and a PR that uses that label so i think it is time to add support for new label that @joyeecheung opened a issue for.

[codecov[bot]]

Codecov Report

Merging #104 into master will increase coverage by 0.17%. The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #104      +/-   ##
==========================================
+ Coverage   91.11%   91.28%   +0.17%     
==========================================
  Files          14       14              
  Lines         540      551      +11     
==========================================
+ Hits          492      503      +11     
  Misses         48       48

Impacted Files	Coverage Δ
lib/pr_checker.js	97.14% <100%> (+0.19%)	:arrow_up:

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[refack]

Optional: still emit a warning that it's a fast-tracked PR and the lander should double check, and use discretion.

[priyank-p]

@refack i think that was a good suggestion to add warn msg for fast-track commits. done

[joyeecheung]

Hmmm, do we need to warn about that tho? Maybe info?

[joyeecheung]

(This reminds me I forgot to open the PR to update collaborator's guide!....)

[priyank-p]

@joyeecheung fixed it.

[priyank-p]

Adding do-not-land label until the PR is ready to get merged.

(I though the label was ready to go in core. But it seems like it not yet!)

[joyeecheung]

BTW: https://github.com/nodejs/node/pull/17056 has landed, the current rule is:

When a pull request is deemed suitable to be fast-tracked, label it with fast-track. The pull request can be landed once 2 or more collaborators approve both the pull request and the fast-tracking request, and the necessary CI testing is done.

[priyank-p]

@joyeecheung just want to know if the code-and-learn and/or doc PRs counts as fast-tracked because we currently count them as being fast-tracked.

BTW this is what i currently have:

# if it can be fast-tracked, have two approvals a CI cli.info
This PR is being fast-tracked
# else if missing approvals or ci or both cli.warn
This PR is being fast-tracked, but awaiting approvals of 2 contributors # or
This PR is being fast-tracked, but awaiting a CI run # or
This PR is being fast-tracked, but awaiting approvals of 2 contributors and a CI run

and so it will warn if there is CI for docs (IIRC there is no CI testing for docs or maybe its linter)

[joyeecheung]

@cPhost I would suggest to skip the code-and-learn and doc rules and just check for fast-track. If it should be fast-tracked, people should label it.

[priyank-p]

@joyeecheung done.