name: "CI"
on:
  # Run only when pushing to master branch, and making PRs
  push:
    branches:
      - master
  pull_request:
jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
      - uses: cachix/install-nix-action@v17
        with:
          extra_nix_config: |
            experimental-features = nix-command flakes
            access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
      - name: Cache Nix dependencies
        run: |
          nix develop -j 4 -c echo
      - name: Build 🔨
        id: build
        run: |
          nix build -j auto -L
      - name: Flake checks 🧪
        run: |
          # Because 'nix flake check' is not system-aware
          # See https://srid.ca/haskell-template/checks
          nix run nixpkgs#sd 'systems = nixpkgs.lib.systems.flakeExposed' 'systems = [ "x86_64-linux" ]' flake.nix

          # Sandbox must be disabled due to HLS,
          # https://github.com/haskell/haskell-language-server/issues/3128
          nix --option sandbox false flake check -L