check_for_changeset.yml

name: Check for changeset

on:
  pull_request:
    types:
      # On by default if you specify no types.
      - 'opened'
      - 'reopened'
      - 'synchronize'
      # For `skip-label` only.
      - 'labeled'
      - 'unlabeled'

jobs:
  check-for-changeset:
    name: Check for changeset
    runs-on: ubuntu-latest
    permissions:
      contents: read
      pull-requests: read
    steps:
      - name: 'Check for changeset'
        env:
          GH_TOKEN: ${{ github.token }}
          PR_NUMBER: ${{ github.event.pull_request.number }}
          SKIP_LABEL: 'skip changeset'
        run: |
          set -euo pipefail

          if jq -r '.pull_request.labels[]?.name // empty' "$GITHUB_EVENT_PATH" | grep -Fxq "$SKIP_LABEL"; then
            echo "The skip label \"$SKIP_LABEL\" is set"
            exit 0
          fi

          changed_files="$(gh api --paginate "repos/$GITHUB_REPOSITORY/pulls/$PR_NUMBER/files" --jq '.[].filename')"

          if grep -Eq '^\.changeset/[^/]+\.md$' <<<"$changed_files"; then
            echo 'The ".changeset/*.md" file pattern matched the changed files of the pull request'
            exit 0
          fi

          failure_message="No changeset found. If these changes should not result in a new version, apply the \"$SKIP_LABEL\" label to this pull request. If these changes should result in a version bump, please add a changeset https://git.io/J6QvQ"
          echo "::error::$failure_message"
          exit 1