ci.yml

name: CI

on:
  # Build every pull request, to check for regressions.
  pull_request:
    types: [opened, synchronize]

  # Build when a PR is merged, to update the README's CI badge.
  push:
    branches: [main]

  # Build once a month, to detect missing upper bounds.
  schedule:
    - cron: '0 0 1 * *'
  
  workflow_dispatch:

jobs:
  stack:
    name: ${{ matrix.name }}
    runs-on: ${{ matrix.os }}
    strategy:
      matrix:
        include:
          # Check that the build passes with the recommended snapshot.
          - name: stable
            stack_yaml: "stack.yaml"
            os: ubuntu-latest

          # Check that the lower bounds are still correct by building with the
          # lowest-supported version of all our dependencies.
          - name: oldest
            stack_yaml: "oldest-supported-lts.yaml"
            os: ubuntu-latest

    steps:
    - uses: actions/checkout@v2

    # see https://github.com/actions/cache/issues/403
    - name: Work around actions/cache bug
      if: matrix.os == 'macos-latest'
      run: |
        brew update && brew install gnu-tar
        echo PATH="/usr/local/opt/gnu-tar/libexec/gnubin:$PATH" >> $GITHUB_ENV

    - uses: actions/cache@v2
      name: Cache Stack Artifacts
      with:
        path: |
          ~/.stack
          ~/.local/bin
          .stack-work
        key: ${{ runner.os }}-stack-${{ hashFiles(matrix.stack_yaml) }}-6

    - uses: haskell-actions/setup@v2
      id: setup-haskell-stack
      name: Setup Stack
      with:
        enable-stack: true
        stack-setup-ghc: true
        stack-no-global: true

    # For some reason, installing happy from lts-9.0 fails unless some other
    # version of happy is already in the PATH. So let's install a version of
    # happy from an lts which does not have this problem.
    - name: Install happy
      if: matrix.stack_yaml == 'oldest-supported-lts.yaml'
      run: |
        stack --stack-yaml=stack.yaml install happy

    - name: Build with happy hack
      if: matrix.stack_yaml == 'oldest-supported-lts.yaml'
      run: |
        PATH="$HOME/.local/bin:$PATH" stack --stack-yaml=${{ matrix.stack_yaml }} install --test --bench --no-run-tests --no-run-benchmarks

    - name: Build
      if: matrix.stack_yaml == 'stack.yaml'
      run: |
        stack --stack-yaml=${{ matrix.stack_yaml }} install --test --bench --no-run-tests --no-run-benchmarks

    - name: Test
      run: |
        stack --stack-yaml=${{ matrix.stack_yaml }} test

    - name: Run installed exe
      run: |
        stack run '2+2'
        ~/.local/bin/hawk '2+2'

  cabal:
    name: ${{ matrix.name }}
    runs-on: ${{ matrix.os }}
    strategy:
      matrix:
        include:
          # Check that our upper bounds are correct by building with the latest
          # version of everything. We use cabal because it uses the latest
          # versions of our dependencies allowed by our upper bounds.
          #
          # TODO: revert to "ghc: latest" once the latest version of ghc is
          # supported, so we can detect when an even-more-recent version of ghc
          # is released and breaks hawk.
          - name: newest
            ghc: 8.10.4
            os: ubuntu-latest

    steps:
    - uses: actions/checkout@v2

    - uses: haskell-actions/setup@v2
      id: setup-haskell-cabal
      name: Setup Cabal
      with:
        ghc-version: ${{ matrix.ghc }}
        cabal-version: ${{ matrix.cabal }}

    # This freeze file is regenerated on every build, so we will always test
    # with the most recent version of our dependencies allowed by our upper
    # bounds.
    - name: Freeze
      run: |
        cabal v2-configure --enable-tests --enable-benchmarks --test-show-details=direct
        cabal freeze

    # Only reuse the cached copy of our dependencies if our freeze file matches
    # the cache's copy.
    - uses: actions/cache@v2
      name: Cache Cabal Artifacts
      with:
        path: |
          ${{ steps.setup-haskell-cabal.outputs.cabal-store }}
        key: ${{ runner.os }}-cabal-v2-${{ hashFiles('cabal.project.freeze') }}

    - name: Build
      run: |
        cabal v2-build --enable-tests

    - name: Test
      run: |
        rm -rf dist-newstyle/sdist sdist
        cabal sdist
        cp -r dist-newstyle/sdist .
        cd sdist
        tar xzvf *.tar.gz
        rm -rf *.tar.gz
        cd *
        cabal test