linter.yml

name: Linting

# Trigger each time HEAD branch is updated in a pull request
# see https://github.com/orgs/community/discussions/26366
on:
  pull_request:
    types: [opened, reopened, synchronize, ready_for_review]

jobs:

  # Resources:
  # number [1] being most important
  # [1] https://github.com/actions/checkout/issues/520#issuecomment-1167205721
  # [2] https://robertfaldo.medium.com/commands-to-run-rubocop-and-specs-you-changed-in-your-branch-e6d2f2e4110b
  # [3] https://community.atlassian.com/t5/Bitbucket-questions/Git-diff-show-different-files-than-PR-Pull-Request/qaq-p/2331786
  rubocop:
    name: RuboCop (Ruby)
    runs-on: ubuntu-latest
    steps:
      - name: Checkout PR branch (with test merge-commit)
        uses: actions/checkout@v4
        with:
          fetch-depth: 2 # to also fetch parent of PR
      
      # Adapted from this great comment [1]. Git diff adapted from [2].
      # "|| test $? = 1;" is used to ignore the exit code of grep when no files
      # are found matching the pattern. For the "three dots" ... syntax, see [3].
      - name: Get changed files
        run: |
          files=$(git diff --name-only --diff-filter=ACMR -r HEAD^1...HEAD | grep '\.rb$' || test $? = 1;)
          printf "🎴 Changed ruby files: \n$files"
          echo "CHANGED_FILES=$(echo ${files} | xargs)" >> $GITHUB_ENV
      
      - name: Set up Ruby 3
        if: env.CHANGED_FILES != ''
        uses: ruby/setup-ruby@v1
        with:
          ruby-version: 3.1.4
          bundler-cache: true

      - name: Run RuboCop
        if: env.CHANGED_FILES != ''
        run: |
          echo "🚨 Running RuboCop version: $(bundle info rubocop | head -1)"
          bundle exec rubocop --format github --fail-level 'convention' --force-exclusion -- $CHANGED_FILES
  
  eslint:
      name: ESLint (JS)
      runs-on: ubuntu-latest
      steps:
        - uses: actions/checkout@v4 # used to checkout custom reusable actions

        - name: Checkout code & get changed files
          id: eslint-changed
          uses: ./.github/actions/changed_files/
          with:
            file-extensions: \.js$|\.js.erb$

        - name: Setup Node.js
          if: ${{ steps.eslint-changed.outputs.changed-files }} != ''
          uses: actions/setup-node@v4
          with:
            node-version: '20' # End of Life (EOL): April 2026
        
        - name: Install dependencies
          if: ${{ steps.eslint-changed.outputs.changed-files }} != ''
          run: yarn install

        - name: Run ESLint
          if: ${{ steps.eslint-changed.outputs.changed-files }} != ''
          run: yarn run eslint --ignore-path .gitignore --max-warnings 0 ${{ steps.eslint-changed.outputs.changed-files }}