validate-renovate.yml

name: validate renovate

on:
  pull_request:
    paths:
      - 'renovate.json'
      - '.github/workflows/validate-renovate.yml'

permissions:
  contents: read
  pull-requests: write

jobs:
  lint:
    name: run renovate-config-validator
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - name: run lint and report
        env:
          URL: ${{ github.event.pull_request.html_url }}
          GH_TOKEN: ${{ github.token }}
        run: |
          # renovate: npm:renovate
          ver="37.291.0"
          # pinned on exact version
          package="renovate@=$ver"
          echo "npx: $(npx --version)"
          echo "installing: $package..."
          export H="$(mktemp)"
          echo '{' >> "$H"
          # let's do main part, but avoid pipefail
          (npx --yes --package "$package" -- renovate-config-validator --strict || true)\
            | ruby -e 'File.open(ENV[?H], ?a) {|r| while gets; puts $_; $> = r if $_.strip == "WARN: Config migration necessary" ;end; }'
          echo '}' >> "$H"
          
          # exit early if migration is not required
          if [ "$(wc -c "$H")" -eq 0 ]; then
            exit 0
          fi
          
          echo "---"
          echo "Collected output: $H"
          cat "$H"
          echo "---"
          # init and extract
          OLD="$(mktemp)"
          mv "$OLD" "${OLD}.old.txt"
          NEW="$(mktemp)"
          mv "$NEW" "${NEW}.new.txt"
          echo "extracting fields"
          jq -r '.oldConfig' < "$H" > "${OLD}.old.txt"
          jq -r '.newConfig' < "$H" > "${NEW}.new.txt"
          
          DIFF_TO_BE_REPORTED="$(mktemp)"
          mv "$DIFF_TO_BE_REPORTED" "${DIFF_TO_BE_REPORTED}.diff"
          echo "computing diff"
          # fold into $?=0 even if they are different:
          # > This form implies --exit-code
          GIT_TRACE=1 git diff --no-index "$OLD.old.txt" "$NEW.new.txt" >> "${DIFF_TO_BE_REPORTED}.diff" || true
          COMMENT_BUFFER="$(mktemp)"
          sep='EOS_SOMEWHAT_DUMMY_LINES'
          echo "I'm sorry, but this config should be migrated. Please apply following patch file to proceed:" >> "$COMMENT_BUFFER"
          echo '```sh >> "$COMMENT_BUFFER"
          # header
          echo '#!/bin/sh' >> "$COMMENT_BUFFER"
          # make temporary
          echo 'd="$(mktemp)"' >> "$COMMENT_BUFFER"
          # patch body to temporary file:
          # cat << $sep
          # ${DIFF_TO_BE_REPORTED}.diff
          # $sep > "$d"
          printf 'cat <<' >> "$COMMENT_BUFFER"
          printf '%s\n' "$sep" >> "$COMMENT_BUFFER"
          cat "${DIFF_TO_BE_REPORTED}.diff" >> "$COMMENT_BUFFER"
          printf "$sep" >> "$COMMENT_BUFFER"
          printf '> "$d"\n' >> "$COMMENT_BUFFER"
          # apply patch
          echo 'patch -p1 < "$d"' >> "$COMMENT_BUFFER"
          # close code-block
          echo '```' >> "$COMMENT_BUFFER"
          echo >> "$COMMENT_BUFFER"
          echo '<details>' >> "$COMMENT_BUFFER"
          echo >> "$COMMENT_BUFFER"
          echo '<summary>Patch</summary>'
          echo >> "$COMMENT_BUFFER"
          echo '```patch' >> "$COMMENT_BUFFER"
          cat "${DIFF_TO_BE_REPORTED}.diff" >> "$COMMENT_BUFFER"
          echo '```' >> "$COMMENT_BUFFER"
          echo >> "$COMMENT_BUFFER"
          echo '</details>' >> "$COMMENT_BUFFER"
          echo '--- [DEBUG] REPORTER ---'
          cat "$COMMENT_BUFFER"
          echo '------------------------'

          gh pr comment -F "$COMMENT_BUFFER" "${URL}"