generate_pr_commit_message.yml

#/
# @license Apache-2.0
#
# Copyright (c) 2024 The Stdlib Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#/

# Workflow name:
name: generate_pr_commit_message

# Workflow triggers:
on:
  pull_request_target:
    types:
      - labeled

# Global permissions:
permissions:
  # Allow read-only access to the repository contents:
  contents: read

  # Allow write access to issues, assignees, labels, and milestones:
  issues: write

  # Allow write access to pull requests:
  pull-requests: write

# Workflow jobs:
jobs:

  # Job to generate commit message draft:
  generate-commit-message:

    # Define a display name:
    name: 'Generate PR Commit Message Draft'

    # Define the type of virtual host machine:
    runs-on: ubuntu-latest

    # Ensure the job only runs when the specified label is added:
    if: github.event.label.name == 'Ready to Merge'

    # Define environment variables:
    env:
      PR_NUMBER: ${{ github.event.pull_request.number }}

    # Define the sequence of job steps...
    steps:
      # Checkout repository:
      - name: 'Checkout repository'
        # Pin action to full length commit SHA
        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
        with:
          # Fetch all commits to ensure we have the full commit history:
          fetch-depth: 0

      # Generate commit message:
      - name: 'Generate commit message'
        id: commit_message
        run: |
          COMMIT_MESSAGE=$($GITHUB_WORKSPACE/.github/workflows/scripts/generate_pr_commit_message $PR_NUMBER)
          EXIT_CODE=$?

          echo "commit_message<<EOF" >> $GITHUB_OUTPUT
          echo "$COMMIT_MESSAGE" >> $GITHUB_OUTPUT
          echo "EOF" >> $GITHUB_OUTPUT

          if [ $EXIT_CODE -eq 200 ]; then
            echo "has_tracking_issue=true" >> $GITHUB_OUTPUT
          else
            echo "has_tracking_issue=false" >> $GITHUB_OUTPUT
          fi

          # Ensure the script itself doesn't fail the workflow:
          exit 0

      # Post commit message as PR comment:
      - name: 'Post commit message as PR comment'
        # Pin action to full length commit SHA
        uses: peter-evans/create-or-update-comment@71345be0265236311c031f5c7866368bd1eff043 # v4.0.0
        with:
          token: ${{ secrets.STDLIB_BOT_PAT_REPO_WRITE }}
          issue-number: ${{ github.event.pull_request.number }}
          body: |
            ### PR Commit Message

            ```text
            ${{ steps.commit_message.outputs.commit_message }}
            ```

            *Please review the above commit message and make any necessary adjustments.*

            ${{ steps.commit_message.outputs.has_tracking_issue == 'true' && '⚠️ **Action Required**: This PR references tracking issues. Please update the PR description to replace any "Closes", "Fixes", or "Resolves" keywords with "Ref" when referencing these issues.' || '' }}