cpp-linter.yml

# Taken mostly from https://cpp-linter.github.io/cpp-linter-action/examples/

name: cpp-linter
on:
  pull_request:
    branches: [main]
    types: [opened, reopened, synchronize, ready_for_review]
  push:
    branches: [main]

jobs:
  cpp-linter:
    # only run on non-draft PRs, this will skip the job for drafts and report success, but drafts can not be merged anyway
    if: ${{ github.event_name != 'pull_request' || github.event.pull_request.draft == false }}
    runs-on: ubuntu-latest
    permissions: 
      pull-requests: write
    steps:
      - uses: actions/checkout@v5

      # Detect if any relevant files changed
      - name: Detect relevant files
        id: filter
        uses: dorny/paths-filter@v3
        with:
          filters: |
            cpp:
              - '**/*.c'
              - '**/*.cpp'
              - '**/*.h'
              - '**/*.hpp'
              - '**/*.cxx'
              - '**/*.hxx'
              - '**/*.cc'
              - '**/*.hh'
              - '**/CMakeLists.txt'
              - 'meson.build'
              - '**/*.cmake'

      # ... optionally setup build env to create a compilation database

      - name: Run cpp-linter
        id: linter
        uses: cpp-linter/cpp-linter-action@v2
        if: steps.filter.outputs.cpp == 'true'
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        with:
          version: 21 # default is 18

          style: 'file'  # Use .clang-format config file. 
          tidy-checks: '-*' # disable clang-tidy checks.
          
          # only 'update' a single comment in a pull request's thread. 
          thread-comments: ${{ github.event_name == 'pull_request' && 'update' }}
          
          # disable file annotations, the thread comment should be the response
          file-annotations: false

      # Fail the job only if the linter ran and found issues
      - name: Fail fast if linter failed
        if: steps.filter.outputs.cpp == 'true' && steps.linter.outputs.checks-failed > 0
        run: exit 1

      # Optional: print a message if no relevant files changed
      - name: Skip message
        if: steps.filter.outputs.cpp != 'true'
        run: echo "No relevant C/C++/CMake files changed — cpp-linter skipped"