go-update-commenter.yml

name: "Go update commenter"

on:
  pull_request:
    # Only run on PR label events (in particular not on every commit)
    types: [ labeled ]

permissions: {}

jobs:
  old-versions-match:
    # Only run if the PR is labeled with 'go-update'
    if: ${{ github.event.label.name == 'go-update' }}
    runs-on: ubuntu-latest
    steps:
      # get the Go version of the target branch
      - uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b # v4.1.4
        with:
          ref: ${{ github.base_ref }}
      - name: Get former Go version
        id: former_go_version
        run: |
          echo version="$(cat .go-version)" >> $GITHUB_OUTPUT

      # get the Go version of the PR branch
      - uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b # v4.1.4
      - name: Get current Go version
        id: new_go_version
        run: |
          echo version="$(cat .go-version)" >> $GITHUB_OUTPUT

      # build the comment
      - name: Build full comment
        id: old_versions
        run: |
          set -euo pipefail
          # build the base of the Github URL to the current commit
          GITHUB_HEAD_URL='${{ github.server_url }}/${{ github.repository }}/blob/${{ github.sha }}'
          {
            echo "matches<<EOF"
            echo "Here are potential matches of the former version:"
            echo ""

            # this step builds a Markdown list of potential matches
            # the script `detect-old-version.sh` displays each matching line as "file:line_number:line_content"
            # the sed command transforms this format into a markdown list with Github permalink URL for each file/line
            # note that the sed command only works properly with GNU sed (MacOS sed doesn't seem to understand \S properly)
            bash -x ./tools/go-update/detect-old-version.sh "${{ steps.former_go_version.outputs.version }}" "${{ steps.new_go_version.outputs.version }}" | \
              sed -E 's|^([^:]+):([^:]+):\s*(\S.*)$|- [\1:\2]('"$GITHUB_HEAD_URL"'/\1#L\2): `\3`|'

            echo "EOF"
          } >> $GITHUB_OUTPUT

      # and display it
      - uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7.0.1
        env:
          # We need to store the output in an environment variable and not use it directly in the createComment,
          # as it will likely not be a valid JS string (eg. if it contains a quote character)
          CONTENT: ${{ steps.old_versions.outputs.matches }}
        with:
          script: |
            github.rest.issues.createComment({
              issue_number: context.issue.number,
              owner: context.repo.owner,
              repo: context.repo.repo,
              body: process.env.CONTENT
            })