name: CI
on:
  pull_request:
  push:
    branches:
    - master
    - ci

jobs:
  check-flake:
    name: Check flake
    runs-on: ubuntu-latest
    steps:
    - name: Checkout
      uses: actions/checkout@v2
      with:
        fetch-depth: 0 # Nix Flakes doesn't work on shallow clones
    - name: Install Nix (flakes, nixos-unstable)
      uses: cachix/install-nix-action@v12
      with:
        install_url: https://github.com/numtide/nix-flakes-installer/releases/download/nix-2.4pre20201221_9fab14a/install
        extra_nix_config: |
          experimental-features = nix-command flakes
        nix_path: nixpkgs=channel:nixos-unstable
    - name: Check flake
      # Building checks is too slow.
      run: nix flake check -v --show-trace --no-build --no-update-lock-file

  check-build-stable:
    name: Check build the latest stable Rust
    runs-on: ubuntu-latest
    steps:
    - name: Checkout
      uses: actions/checkout@v2
      with:
        fetch-depth: 0 # Nix Flakes doesn't work on shallow clones
    - name: Install Nix (flakes, nixos-unstable)
      uses: cachix/install-nix-action@v12
      with:
        install_url: https://github.com/numtide/nix-flakes-installer/releases/download/nix-2.4pre20201221_9fab14a/install
        extra_nix_config: |
          experimental-features = nix-command flakes
        nix_path: nixpkgs=channel:nixos-unstable
    - name: Build
      run: |
        nix build ".#rust" -L
        ./result/bin/rustc --version