nix.yml

name: Nix

# See: https://docs.github.com/en/actions/reference/workflow-syntax-for-github-actions#concurrency.
concurrency:
  group: ${{ github.head_ref }}-${{ github.workflow }}
  cancel-in-progress: true

on:
  pull_request:
    branches:
      - '**'
  push:
    branches:
      - master

jobs:
  pre_job:
    runs-on: ubuntu-latest
    outputs:
      should_skip_develop: ${{ steps.skip_check.outputs.should_skip }}
    steps:
      - id: skip_check
        uses: fkirc/skip-duplicate-actions@v5.3.1
        with:
          cancel_others: false
          paths_ignore: '[ "**/docs/**"
                         , "**.md"
                         , "**/LICENSE"
                         , ".circleci/**"
                         , "**/README.md"
                         , "FUNDING.yml"
                         , "**/stack*.yaml"
                         , "**/stack*.yaml"
                         , ".gitlab-ci.yaml"
                         , ".gitlab/**"
                         ]'

  # Enter the development shell and run `cabal build`
  develop:
    if: needs.pre_job.outputs.should_skip_develop != 'true'
    needs: pre_job
    runs-on: ${{ matrix.os }}

    strategy:
      fail-fast: false
      matrix:
        os: [ubuntu-latest, macOS-latest]

    steps:
    - uses: actions/checkout@v3

    - uses: cachix/install-nix-action@v30
      with:
        extra_nix_config: |
          experimental-features = nix-command flakes
        nix_path: nixpkgs=channel:nixos-unstable
    - uses: cachix/cachix-action@v15
      with:
        name: haskell-language-server
        authToken: ${{ secrets.HLS_CACHIX_AUTH_TOKEN }}
    # Don't try and run the build (although that would be a good
    # test), it takes a long time and we have sometimes had
    # glibc incompatibilities with the runners
    - run: |
        nix develop --print-build-logs --command true

  nix_post_job:
    if: always()
    runs-on: ubuntu-latest
    needs: [pre_job, develop]
    steps:
      - run: |
          echo "jobs info: ${{ toJSON(needs) }}"
      - if: contains(needs.*.result, 'failure')
        run: exit 1
      - if: contains(needs.*.result, 'cancelled') && needs.pre_job.outputs.should_skip != 'true'
        run: exit 1