Add config option to only apply first match

[KevinBatdorf]

I'd like to have a fallback label applied without any matches.

feature: ['feature/*', 'feat/*']
fix: fix/*
chore: chore/*
unknown: *

So if nothing matches, it will add the label "unknown"

I was thinking you could add a config option where it would return on the first match instead of looping through each (then it would use the * as the fallback if nothing else matched). Does that seem feasible?

[w5l]

This might be a lot easier to do using the action config instead of in the tags yml.

For example:

    steps:
      - uses: TimonVS/pr-labeler-action@v3
        with:
          default-label: 'unknown' # Any PR not matching one of the rules gets this label
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

Can be done by a default-label string option, or by having a first-match-only boolean option.

An interesting thing to keep in mind, a "default label" would be slightly different behavior than a "first match only" in more complex configurations.

[TimonVS]

Great idea. We cannot use the syntax you originally proposed because it's already occupied (currently, this will always add the label, regardless of any other matches). @w5l's proposal should work though! This should be relatively easy to implement, feel free to open a PR for it if you wish.