CI.yml

name: CI
on:
  pull_request:
    branches:
      - main
    paths:
      - "src/**"
      - "test/**"
      - "Project.toml"
      - ".github/workflows/CI.yml"
  push:
    branches:
      - main

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/') }}

jobs:
  ci:
    name: Julia ${{ matrix.version }} - ${{ matrix.os }}
    if: ${{ !contains(github.event.head_commit.message, '[skip tests]') }}
    runs-on: ${{ matrix.os }}
    strategy:
      fail-fast: false
      matrix:
        version:
          - "1"
        os:
          - ubuntu-latest
          - macos-latest
          - windows-latest
    steps:
      - uses: actions/checkout@v4
      - uses: julia-actions/setup-julia@v2
        with:
          version: ${{ matrix.version }}
      - uses: actions/cache@v4
        env:
          cache-name: cache-artifacts
        with:
          path: ~/.julia/artifacts
          key: ${{ runner.os }}-test-${{ env.cache-name }}-${{ hashFiles('**/Project.toml') }}
          restore-keys: |
            ${{ runner.os }}-test-${{ env.cache-name }}-
            ${{ runner.os }}-test-
            ${{ runner.os }}-
      - uses: julia-actions/julia-buildpkg@v1
      - uses: julia-actions/julia-runtest@v1
      - uses: julia-actions/julia-processcoverage@v1
        with:
          directories: src,ext
      - uses: codecov/codecov-action@v4
        with:
          files: lcov.info
          token: ${{ secrets.CODECOV_TOKEN }}
          verbose: true
          fail_ci_if_error: true

  downstream:
    name: Downstream ${{ matrix.package.repo }}/${{ matrix.package.group }}
    runs-on: ${{ matrix.os }}
    timeout-minutes: 60
    env:
      BACKEND_GROUP: ${{ matrix.package.group }}
    strategy:
      fail-fast: false
      matrix:
        julia-version: ["1"]
        os: [ubuntu-latest]
        package:
          - { user: LuxDL, repo: Lux.jl, group: CPU }
    steps:
      - uses: actions/checkout@v4
      - uses: julia-actions/setup-julia@v2
        with:
          version: ${{ matrix.julia-version }}
          arch: x64
      - uses: julia-actions/julia-buildpkg@v1
      - name: Clone Downstream
        uses: actions/checkout@v4
        with:
          repository: ${{ matrix.package.user }}/${{ matrix.package.repo }}
          path: downstream
      - name: Load this and run the downstream tests
        shell: julia --code-coverage=user --color=yes --project=downstream {0}
        run: |
          using Pkg
          try
            # force it to use this PR's version of the package
            Pkg.develop(PackageSpec(path="."))  # resolver may fail with main deps
            Pkg.update()
            Pkg.test(; coverage="user")  # resolver may fail with test time deps
          catch err
            err isa Pkg.Resolve.ResolverError || rethrow()
            # If we can't resolve that means this is incompatible by SemVer and this is fine
            # It means we marked this as a breaking change, so we don't need to worry about
            # Mistakenly introducing a breaking change, as we have intentionally made one
            @info "Not compatible with this release. No problem." exception=err
            exit(0)  # Exit immediately, as a success
          end
      - uses: julia-actions/julia-processcoverage@v1
        with:
          directories: src,ext
      - uses: codecov/codecov-action@v4
        with:
          files: lcov.info
          token: ${{ secrets.CODECOV_TOKEN }}
          verbose: true
          fail_ci_if_error: true

  downgrade:
    if: ${{ !contains(github.event.head_commit.message, '[skip tests]') && github.base_ref == github.event.repository.default_branch }}
    name: Downgrade Julia ${{ matrix.version }}
    runs-on: ubuntu-latest
    strategy:
      fail-fast: false
      matrix:
        version: ["1"]
    steps:
      - uses: actions/checkout@v4
      - uses: julia-actions/setup-julia@v2
        with:
          version: ${{ matrix.version }}
      - uses: julia-actions/julia-downgrade-compat@v1
        with:
          skip: 'AMDGPU'
      - uses: julia-actions/julia-buildpkg@v1
      - uses: julia-actions/julia-runtest@v1
        env:
          RETESTITEMS_NWORKERS: 4
          RETESTITEMS_NWORKER_THREADS: 2
      - uses: julia-actions/julia-processcoverage@v1
        with:
          directories: src,ext
      - uses: codecov/codecov-action@v4
        with:
          files: lcov.info
          token: ${{ secrets.CODECOV_TOKEN }}
          verbose: true
          fail_ci_if_error: true

  invalidations:
    # Only run on PRs to the default branch.
    # In the PR trigger above branches can be specified only explicitly whereas this check should work for master, main, or any other default branch
    if: github.base_ref == github.event.repository.default_branch
    runs-on: ubuntu-latest
    steps:
      - uses: julia-actions/setup-julia@v2
        with:
          version: "1"
      - uses: actions/checkout@v4
      - uses: julia-actions/julia-buildpkg@v1
      - uses: julia-actions/julia-invalidations@v1
        id: invs_pr

      - uses: actions/checkout@v4
        with:
          ref: ${{ github.event.repository.default_branch }}
      - uses: julia-actions/julia-buildpkg@v1
      - uses: julia-actions/julia-invalidations@v1
        id: invs_default

      - name: Report invalidation counts
        run: |
          echo "Invalidations on default branch: ${{ steps.invs_default.outputs.total }} (${{ steps.invs_default.outputs.deps }} via deps)" >> $GITHUB_STEP_SUMMARY
          echo "This branch: ${{ steps.invs_pr.outputs.total }} (${{ steps.invs_pr.outputs.deps }} via deps)" >> $GITHUB_STEP_SUMMARY
      - name: Check if the PR does increase number of invalidations
        if: steps.invs_pr.outputs.total > steps.invs_default.outputs.total
        run: exit 1

env:
  RETESTITEMS_NWORKERS: 4
  RETESTITEMS_NWORKER_THREADS: 2