milestone-add-to-pr.yml

# This action adds the "next release" milestone to a pull request
# when it is merged. The "next release" milestone is managed
# by the "Project: Rotate Milestone" action.

name: 'Project: Add PR to Milestone'
on:
  pull_request_target:
    types:
      - closed

jobs:
  update-pr:
    if: github.event.pull_request.merged
    runs-on: ubuntu-latest
    steps:
      - uses: actions/github-script@v6
        with:
          script: |
            const milestones = await github.rest.issues.listMilestones({
              owner: context.repo.owner,
              repo: context.repo.repo,
              state: "open"
            })
            for (const milestone of milestones.data) {
              if (milestone.title == "next release") {
                await github.rest.issues.update({
                  owner: context.repo.owner,
                  repo: context.repo.repo,
                  issue_number: context.issue.number,
                  milestone: milestone.number
                });
                return
              }
            }