Downgrade.yml

name: Downgrade

on:
  pull_request:
    paths-ignore:
      - 'AUTHORS.md'
      - 'CITATION.bib'
      - 'CONTRIBUTING.md'
      - 'LICENSE.md'
      - 'NEWS.md'
      - 'README.md'
      - '.zenodo.json'
      - '.github/workflows/CompatHelper.yml'
      - '.github/workflows/Documenter.yml'
      - '.github/workflows/Format-check.yml'
      - '.github/workflows/TagBot.yml'
      - '.github/workflows/SpellCheck.yml'
      - 'docs/**'
  workflow_dispatch:

# Cancel redundant CI tests automatically
concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true

jobs:
  downgrade_test:
    if: "!contains(github.event.head_commit.message, 'skip ci')"
    # We could also include the Julia version as in
    # name: ${{ matrix.trixi_test }} - ${{ matrix.os }} - Julia ${{ matrix.version }} - ${{ matrix.arch }} - ${{ github.event_name }}
    # to be more specific. However, that requires us updating the required CI tests whenever we update Julia.
    name: Downgrade ${{ matrix.os }} - ${{ matrix.arch }} - ${{ github.event_name }}
    runs-on: ${{ matrix.os }}
    strategy:
      fail-fast: false
      matrix:
        version:
          - '1.9'
          # - '~1.9.0-0' # including development versions
          # - 'nightly'
        os:
          - ubuntu-latest
        arch:
          - x64
    steps:
      - uses: actions/checkout@v4
      - uses: julia-actions/setup-julia@v2
        with:
          version: ${{ matrix.version }}
          arch: ${{ matrix.arch }}
      - run: julia -e 'using InteractiveUtils; versioninfo(verbose=true)'
      - uses: julia-actions/cache@v1
      - uses: julia-actions/julia-downgrade-compat@v1
        with:
          skip: UUIDs
          projects: ., test
      - uses: julia-actions/julia-buildpkg@v1
        env:
          PYTHON: ""
      - name: Run tests without coverage
        uses: julia-actions/julia-runtest@v1
        with:
          coverage: false
        env:
          PYTHON: ""