Retrieve target branch from PR label(s)

[lampajr]

There are use cases where the target branch is not always fixed, instead it is dynamically computed from the original PR label(s).
That is why we created this additional workflow step [1] to properly parse labels with a prefixed pattern and extracting the target branch from them, this could be hard to maintain and error-prone.

Proposal: integrate this step in the tool itself, in this way target-branch will become optional and you can provide the regex/pattern to use in order to extract the target branch from the original PR labels, if any.

[1] https://github.com/kiegroup/droolsjbpm-build-bootstrap/blob/main/.github/workflows/pr-backporting.yml#L12-L25

Tasks

Beta Give feedback

1. Handle multiple target-branch #77
   enhancement +1
   

[earl-warren]

here is a snippet for inspiration, from a similar action:

const getBaseBranches = ({
  labelRegExp,
  payload,
}: Readonly<{
  labelRegExp: RegExp;
  payload: PullRequestClosedEvent | PullRequestLabeledEvent;
}>): string[] => {
  if ("label" in payload) {
    const base = getBaseBranchFromLabel(payload.label.name, labelRegExp);
    return base ? [base] : [];
  }

  return compact(
    payload.pull_request.labels.map((label) =>
      getBaseBranchFromLabel(label.name, labelRegExp),
    ),
  );
};

[lampajr]

That's a good hint, thanks @earl-warren for the reference!