linter.yml

name: Linting

on:
  push:
    branches:
      - '**'
  pull_request:
    branches:
      - 'main' # Continuous Releases

jobs:

  rubocop:
    name: RuboCop
    runs-on: ubuntu-latest
    steps:
      - name: 'Checkout PR branch (with test merge-commit)'
        uses: actions/checkout@v3
        with:
          fetch-depth: 2
      - name: 'Get a list of changed files to process'
        run: git diff-tree --name-only --diff-filter 'AM' -r HEAD^1 HEAD

      - name: Determine target branch
        run: |
          target_branch=${{ github.base_ref || 'mampf-next' }}
          echo "Target branch is: $target_branch"
          echo "TARGET_BRANCH=$target_branch" >> $GITHUB_ENV

      # for the " + 1", see:
      # https://github.com/actions/checkout/issues/552#issuecomment-1167086216 
      - name: Calculate fetch depth
        run: |
          depth=$(( ${{ github.pull_request.commits }} + 1 ))
          echo "Fetch depth is: $depth"
          echo "PR_FETCH_DEPTH=$depth" >> $GITHUB_ENV
      
      - name: 'Checkout PR branch and all PR commits'
        uses: actions/checkout@v3
        with:
          ref: ${{ github.pull_request.head.ref }}
          fetch-depth: ${{ env.PR_FETCH_DEPTH }}
      
      - name: Fetch target branch with enough history for a common merge-base commit
        run: |
          git fetch origin ${{ github.pull_request.base.ref }}

      - name: Set up Ruby 3
        uses: ruby/setup-ruby@v1
        with:
          ruby-version: 3.1.4
          bundler-cache: true

      # If this action is not triggered from a PR, we use 'mampf-next' as default
      # target branch to compare against. This might not cover all use cases.
      # But in the end, one has to open a PR anyways and then the correct target
      # branch is identified.
      # TODO: rename to 'dev' when 'mampf-next' branch is renamed.
      # - name: Fetch target branch
      #   run: |
      #     targetBranch=${{ github.base_ref || 'mampf-next' }}
      #     echo "Target branch is: $targetBranch"
      #     git fetch origin $targetBranch:$targetBranch --depth=1

      # adapted from https://github.com/actions/checkout/issues/520#issuecomment-1167205721
      # and: https://robertfaldo.medium.com/commands-to-run-rubocop-and-specs-you-changed-in-your-branch-e6d2f2e4110b
      # --diff-filter=d excludes deleted files
      # "|| test $? = 1;" is used to ignore the exit code of grep when no files
      # are found matching the pattern
      # For the "three dots" ... syntax, see
      # https://community.atlassian.com/t5/Bitbucket-questions/Git-diff-show-different-files-than-PR-Pull-Request/qaq-p/2331786
      - name: Get changed ruby files (git diff)
        run: |
          changedFiles=$(git diff --name-only --diff-filter=d -r $targetBranch...HEAD | grep '\.rb$' || test $? = 1;)
          printf "Changed ruby files: \n$changedFiles"
          echo "CHANGED_FILES=\"$changedFiles\"" >> $GITHUB_ENV

      # See RuboCop command line flags here:
      # https://docs.rubocop.org/rubocop/usage/basic_usage.html#command-line-flags
      # - name: Run RuboCop
      #   if: env.CHANGED_FILES != ''
      #   run: $CHANGED_FILES | xargs bundle exec rubocop


  # eslint:
  #   runs-on: ubuntu-latest
  #   name: A job to check eslint linter errors
  #   steps:
  #     - uses: actions/checkout@v2
  #     - name: Linter count
  #       id: hello
  #       uses: henrixapp/linter-less-or-equal-action@v1.19
  #       with:
  #         name: EsLint
  #         command: npx eslint
  #         total_regexp: \d+ problems
  #         errors_regexp: \d+ errors
  #         warnings_regexp: \d+ warnings
  #         compare_branch: mampf-next
  #         mode: changed
  #         include: .js
  # coffee:
  #   runs-on: ubuntu-latest
  #   name: A job to check coffee linter errors
  #   steps:
  #     - uses: actions/checkout@v2
  #     - name: Linter count
  #       id: hello
  #       uses: henrixapp/linter-less-or-equal-action@v1.19
  #       with:
  #         name: Coffee
  #         command: npx coffeelint
  #         total_regexp: \d+ errors
  #         errors_regexp: \d+ errors
  #         warnings_regexp: \d+ warnings
  #         compare_branch: mampf-next
  #         mode: changed
  #         include: .coffee
  # erblint:
  #   runs-on: ubuntu-latest
  #   name: A job to check erblint linter errors
  #   steps:
  #   - uses: actions/checkout@v2
  #   - name: Set up Ruby 2.7
  #     uses: ruby/setup-ruby@v1
  #     with:
  #       ruby-version: 2.7
  #   - name: Install gems # usual step to install the gems.
  #     run: |
  #       bin/bundle config path vendor/bundle
  #       bin/bundle config set without 'default doc job cable storage ujs test db'
  #       bin/bundle install --jobs 4 --retry 3
  #   - name: Linter count
  #     id: hello
  #     uses: henrixapp/linter-less-or-equal-action@v1.1
  #     with:
  #       name: Erblint
  #       command:  bin/bundle exec erblint  . 
  #       total_regexp: \d+ error(s)
  #       errors_regexp: \d+ error(s)
  #       warnings_regexp: \d+ error(s)
  #       compare_branch: mampf-next