Comprehensive Haskell CI

haskell_ci.yml

jobs:
  tool-output:
    runs-on: ubuntu-latest
    outputs:
      ghc_versions: ${{ steps.gen_output.outputs.ghc_versions }}

    steps:

    - uses: haskell/ghcup-setup@v1

    - name: Generate output
      id: gen_output
      run: |
        all="$(ghcup -s GHCupURL list -r -t ghc -c available)"
        rec=$(echo "${all}"         | grep recommended | awk '{ print $2 }')
        latest=$(echo "${all}"      | grep latest      | awk '{ print $2 }')

        other_major=$(echo "${all}" | awk '{ print $2 }' | awk -F '.' '{ print $1 "." $2}' | sort -Vu | tail -5)
        other=$(for v in $other_major ; do point_releases=$(echo "$all" | awk '{ print $2 }' | grep --color=never "^$v.") ; echo "${point_releases}" | tail -n1  ; done)

        selected=$(echo -n ${rec} ${latest} ${other} | tr " " "\n"  | sort -Vu)
        selected_json=$(echo -n $selected | jq -c -r -R 'split(" ") | [ .[] | if length > 0 then . else empty end ]')

        echo "${selected}"
        echo "${selected_json}"

        echo ghc_versions="${selected_json}" >> "$GITHUB_OUTPUT"

  build:
    runs-on: ${{ matrix.os }}
    needs: ["tool-output"]
    strategy:
      fail-fast: false
      matrix:
        os: [ubuntu-latest, ubuntu-24.04-arm, macOS-15-intel, macOS-latest, windows-latest]
        ghc: ${{ fromJSON(needs.tool-output.outputs.ghc_versions) }}
    steps:
    - uses: actions/checkout@v4

    - name: Install dependencies (Ubuntu)
      if: runner.os == 'Linux'
      run: |
        sudo apt-get -y update
        sudo apt-get -y install build-essential curl libffi-dev libgmp-dev libncurses-dev pkg-config

    - uses: haskell/ghcup-setup@v1
      with:
        ghc: ${{ matrix.ghc }}
        cabal: latest

    - name: Build
      run: |
        cabal update
        cabal test --test-show-details=direct all