check-milestone.yml

name: Check Milestone

on:
  pull_request:
    types: [opened, edited, synchronize, milestoned, demilestoned]

jobs:
  check-milestone:
    name: Validate milestone
    runs-on: ubuntu-latest
    permissions:
      pull-requests: read
    steps:
      - name: Check milestone is set
        if: github.event.pull_request.milestone == null
        run: |
          echo "::error::This PR does not have a milestone set. Please assign a milestone before merging."
          exit 1

      - name: Check milestone is open
        if: github.event.pull_request.milestone != null && github.event.pull_request.milestone.state != 'open'
        run: |
          echo "::error::Milestone '${{ github.event.pull_request.milestone.title }}' is ${{ github.event.pull_request.milestone.state }}. Please assign an open milestone."
          exit 1