when:
  - event: pull_request
  - event: push
    branch:
      - ${CI_REPO_DEFAULT_BRANCH}

steps:
  check:
    image: alpine
    volumes:
      - nix:/nix
    commands:
      # install nix
      - |
        test -f /nix/installer || wget -O /nix/installer https://github.com/DeterminateSystems/nix-installer/releases/download/v0.18.0/nix-installer-x86_64-linux
        chmod +x /nix/installer
        rm -f /nix/receipt.json /nix/nix-installer
        /nix/installer install linux --init=none --no-confirm
        . /nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh

      # configure nix
      - |
        mkdir -p /etc/nix
        cat <<EOF > /etc/nix/nix.conf
        sandbox = false
        experimental-features = nix-command flakes
        EOF

      # build
      - nix build .

      # check
      - nix flake check