downgrade.yml

name: Downgrade

on:
  push:
    branches:
      - main
    paths-ignore:
      - 'LICENSE.md'
      - 'README.md'
      - '.zenodo.json'
      - '.github/workflows/CompatHelper.yml'
      - '.github/workflows/TagBot.yml'
      - 'docs/**'
  pull_request:
    paths-ignore:
      - 'LICENSE.md'
      - 'README.md'
      - '.zenodo.json'
      - '.github/workflows/CompatHelper.yml'
      - '.github/workflows/TagBot.yml'
      - 'docs/**'
  workflow_dispatch:

concurrency:
  # Skip intermediate builds: always.
  # Cancel intermediate builds: only if it is a pull request build.
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: ${{ startsWith(github.ref, 'refs/pull/') }}

# needed to allow julia-actions/cache to delete old caches that it has created
permissions:
  actions: write
  contents: read

jobs:
  downgrade_test:
    if: "!contains(github.event.head_commit.message, 'skip ci')"
    name: Downgrade - ${{ matrix.trixi_test }} - ${{ matrix.os }} - ${{ matrix.arch }}
    runs-on: ${{ matrix.os }}
    strategy:
      fail-fast: false
      matrix:
        version:
          - '1.10'
        os:
          - ubuntu-latest
        arch:
          - x64
        trixi_test:
          - upstream
    steps:
      - uses: actions/checkout@v6
      - 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@v2
      - uses: julia-actions/julia-downgrade-compat@v2
        with:
          skip: LinearAlgebra,Printf,Test
          projects: ., test
          mode: forcedeps
      # We run the tests manually instead of using julia-action/julia-builpkg and julia-action/julia-runtest or `Pkg.test`
      # because otherwise the downgraded Manifest.toml is not used in the tests under julia <v1.12
      # see also https://github.com/julia-actions/julia-downgrade-compat/blob/00f940b7be2b50389571ed016d603be561649103/README.md#L89
      - name: Run tests
        run: |
          julia --project=test --color=yes -e '
            import Pkg
            Pkg.develop(Pkg.PackageSpec(path=pwd()))
            Pkg.instantiate()
            Pkg.status(; mode = Pkg.PKGMODE_MANIFEST)
            include("test/runtests.jl")
          '
        env:
          TRIXI_TEST: ${{ matrix.trixi_test }}