updateChangelog.yml

name: Update Changelog with new commit

permissions:
  pull-requests: write
  contents: write

on:
  pull_request:
    # Inputs the workflow accepts.
    types: [closed]

jobs:
  pull-commit-message:
    if: github.event.pull_request.merged == true
    runs-on: ubuntu-latest
    outputs:
      message: ${{ steps.pull.outputs.message }}
    steps:
      - uses: actions/checkout@v4
      - name: get merge commit message 
        id: pull
        run: echo message="$(git log --pretty="format:%b")" >> $GITHUB_OUTPUT
  # check-for-changelog-entry
  changelog-entry:
    # if contains to check for bug, enhancement, breaking change, feature
    if: ${{ contains(needs.pull-commit-message.outputs.message, '[BUG]') || contains(needs.pull-commit-message.outputs.message, '[ENHANCEMENT]') || contains(needs.pull-commit-message.outputs.message, '[FEATURE]') || contains(needs.pull-commit-message.outputs.message, '[BREAKING]')}}
    runs-on: ubuntu-latest
    needs: pull-commit-message
    outputs:
      optIn: ${{ steps.in.outputs.bool }}
      entry: ${{  needs.pull-commit-message.outputs.message  }}
    steps:
      - name: changelog entry opt in
        id: in
        run: echo "opted in to changelog entry" | echo bool="true" >> $GITHUB_OUTPUT
  # if there is a changelog entry, check for PR Open
  update-changelog:
    if: needs.changelog-entry.outputs.optIn
    runs-on: ubuntu-latest
    needs: changelog-entry
    steps:
      - name: Check if PR exists
        id: check
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
          prs=$(gh pr list \
              --repo "$GITHUB_REPOSITORY" \
              --json title \
              --label "changelog" \
              --jq 'length')
          if [[  $prs -gt 0  ]]; then
              echo "existing=true" >> "$GITHUB_OUTPUT"
          fi
      - uses: actions/checkout@v4
        with:
          ref: automated-changelog
      - name: Create pull request
      #if changelog PR isn't already open, open one
      #create a new PR, start with appending the release number and (unreleased)
        if: '!steps.check.outputs.existing'
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
          git config user.email "41898282+github-actions[bot]@users.noreply.github.com"
          git config user.name "github-actions[bot]"
          
          #new pull request for new release needs the headers all added to the top
          FILE="CHANGELOG.md"
          version=$(head -n 1 "$FILE")
          IFS='.' read major minor patch <<< "$version"
          ((minor++))
          patch=$(echo $patch | sed 's/ (.*)//')
          new_version="${major}.$minor.${patch} (Unreleased)"
          headers="${new_version}\n\nBREAKING CHANGES:\n\nENHANCEMENTS:\n\nFEATURES:\n\nBUG FIXES:\n"
          temp_file=$(mktemp)
          echo -e "$headers" > "$temp_file"
          cat "$FILE" >> "$temp_file"
          mv "$temp_file" "$FILE"
          echo "File has been updated."

          git add CHANGELOG.md
          git commit -m "staring new changelog PR"
          git push --set-upstream origin automated-changelog
          echo "Creating a new pull request"
          gh pr create \
          --repo "$GITHUB_REPOSITORY" \
          --base main \
          --head automated-changelog \
          -l "changelog" \
          -t "CHANGELOG.md updates" \
          -b "changelog for next release"
      - name: Add commit message to changelog pull request
      # at this point a PR is opened for sure, now add entry
        env:
            GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
          git config user.email "41898282+github-actions[bot]@users.noreply.github.com"
          git config user.name "github-actions[bot]"
          
          # place the entry within the correct header
          input_string='${{ needs.changelog-entry.outputs.entry }}'
          changelog_file="CHANGELOG.md"
          
          # Extract the type (e.g., BUG or ENHANCEMENT) from the input string
          if [[ $input_string =~ ^\[(BUG|ENHANCEMENT|FEATURE|BREAKING)\] ]]; then
            change_type="${BASH_REMATCH[1]}"
          else
            echo "Invalid input string format. Expected '[BUG]' or '[ENHANCEMENT]' or '[FEATURE]' or '[BREAKING]'."
            exit 1
          fi
          
          # Define the header based on the change type
          if [[ "$change_type" == "BUG" ]]; then
            header="BUG FIXES:"
          elif [[ "$change_type" == "ENHANCEMENT" ]]; then
            header="ENHANCEMENTS:"
          elif [[ "$change_type" == "FEATURE" ]]; then
            header="FEATURES:"
          elif [[ "$change_type" == "BREAKING" ]]; then
            header="BREAKING CHANGES:"
          fi

          input_string=$(echo $input_string | sed -e 's/^\[BUG\] //' -e 's/^\[ENHANCEMENT\] //' -e 's/^\[FEATURE\] //' -e 's/^\[BREAKING\] //')
          
          # Find the header and insert the input string under the first occurrence
          awk -v header="$header" -v input_string="$input_string" '
            BEGIN {
              found_header = 0
            }
          
            # Look for the first occurrence of the header
            $0 ~ header && found_header == 0 {
              found_header = 1
              print $0
              print input_string
              next
            }
          
            # After inserting the input_string, continue printing the rest of the file normally
            { print $0 }
          ' $changelog_file > "${changelog_file}.tmp"
          mv "${changelog_file}.tmp" $changelog_file
          
          echo "The change has been added to the changelog under the first occurrence of $header."

          git add CHANGELOG.md
          git commit -m "Update changelog"
          git push --set-upstream origin automated-changelog