ci.yml

name: CI

on:
  push:
    branches:
      - main
    tags:
      - '*'
  pull_request:

## We specify a concurrency group with automated cancellation. This means that
## other pushes on the same `github.ref` (eg. other pushes to the same pull
## request) cancel previous occurrences of the CI.
concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true

jobs:

  ## ========================= [ OPAM-based CI ] ========================= ##

  opam-based:

    strategy:
      fail-fast: false
      matrix:
        include:
          - {os: ubuntu, ocaml: 4.11.x}  ## in Debian stable (as of 2023-05-11)
          - {os: ubuntu, ocaml: 4.11.x, lower-bounds: lower-bounds, doc: no-doc}
          - {os: ubuntu, ocaml: 4.12.x}
          - {os: ubuntu, ocaml: 4.13.x}
          # {os: ubuntu, ocaml: 4.14.x}  ## main supported version
          - {os: ubuntu, ocaml: 4.14.x, lower-bounds: lower-bounds, doc: no-doc}
          - {os: ubuntu, ocaml: 4.14.x, deploy-doc: deploy-doc}
          - {os: ubuntu, ocaml: 4.14.1, bytecode: bytecode}
          - {os: macos, ocaml: 4.14.x}
          - {os: windows, ocaml: 4.14.x, tests: no-tests}
          - {os: ubuntu, ocaml: 5.0.x}
          ## NOTE: The `ocaml/setup-ocaml@v2` action does not support `4.14.x`
          ## versions for `ocaml-variants` and such, hence the detailed version.
          ## NOTE: After OCaml 5.0.0, `ocaml-option-bytecode-only` can be used
          ## directly with `ocaml-base-compiler`, probably?
          ## NOTE: Tests are written in a Unix-like way and therefore cannot
          ## run correctly on Windows.
          ## NOTE: `lower-bounds` implies to not build the documentation because
          ## `opam-0install`, the solver we use, does not support it. Therefore
          ## we don't even install those dependencies to begin with.

    ## Grant GITHUB_TOKEN the permissions required to make a pages deployment
    permissions:
      pages: write
      id-token: write

    runs-on: ${{ matrix.os }}-latest

    steps:
      - name: Determine OPAM flags
        shell: bash  ## for Windows
        run: |
          if ${{ matrix.doc != 'no-doc' }}; then
            with_doc=--with-doc
          fi
          if ${{ matrix.tests != 'no-tests' }}; then
            with_test=--with-test
          fi
          echo "OPAM_FLAGS=$with_doc $with_test" >> "$GITHUB_ENV"

      - name: Checkout repository
        uses: actions/checkout@v4

      - name: Use OCaml ${{ matrix.ocaml }}
        if: matrix.bytecode != 'bytecode'
        uses: ocaml/setup-ocaml@v2
        with:
          ocaml-compiler: ${{ matrix.ocaml }}

      - name: (Bytecode) Use OCaml ${{ matrix.ocaml }}
        if: matrix.bytecode == 'bytecode'
        uses: ocaml/setup-ocaml@v2
        with:
          ocaml-compiler: ocaml-variants.${{ matrix.ocaml }}+options,ocaml-option-bytecode-only

      - name: Install Dune
        run: opam install dune --yes

      - name: Install OPAM dependencies
        run: opam install . --deps-only ${{ env.OPAM_FLAGS }}

      - name: (Lower bounds) Install OPAM-0install
        if: matrix.lower-bounds == 'lower-bounds'
        run: |
          opam install opam-0install

      - name: (Lower bounds) Ask OPAM-0install for an install plan
        if: matrix.lower-bounds == 'lower-bounds'
        run: |
          ## Based on: https://sim642.eu/blog/2022/03/13/ocaml-dependencies-lower-bounds-ci/
          ## Note the current version of `ocaml-base-compiler`
          obc=ocaml-base-compiler.$(opam exec -- ocamlc --version)
          ## Ask `opam-0install` to get us the oldest possible dependencies for
          ## Morbig, while keeping the exact same version of
          ## `ocaml-base-compiler`.
          opam exec -- \
              opam-0install --prefer-oldest $OPAM_FLAGS morbig.dev $obc \
                  | sed 's|morbig.dev||' \
                  > lower-bounds
          ## Log what we are aiming for
          printf '\e[36m<><>\e[0m Packages to install \e[36m><><><><><><><><><><><><><><><><><><><><><><><><><><><>\e[0m\n'
          printf '`opam-0install` suggests installing the following packages:\n'
          cat lower-bounds | tr ' ' '\n' | sed 's|^\([^.]*\)\.|\t\1\t|' | column -t

      - name: (Lower bounds) Downgrade OPAM dependencies
        if: matrix.lower-bounds == 'lower-bounds'
        run: opam install --yes $(cat lower-bounds)

      - name: Try building
        run: opam exec -- make

      - name: Try building documentation
        if: matrix.doc != 'no-doc'
        run: opam exec -- make doc

      - name: Run tests
        if: matrix.tests != 'no-tests'
        run: opam exec -- make check

      - name: Try installing
        run: opam exec -- make install

      - name: Try building examples
        ## NOTE: Examples are written in a Unix-like way and cannot build on a
        ## bytecode-only infrastructure.
        if: runner.os != 'Windows' && matrix.bytecode != 'bytecode'
        run: opam exec -- make examples

      - name: Try uninstalling
        if: matrix.lower-bounds != 'lower-bounds'
        run: opam exec -- make uninstall

      - name: (Lower bounds) Try uninstalling
        ## NOTE: Old versions of Dune (< 3.1.0) fail when they cannot remove
        ## `bin` or `lib/morbig` in the prefix. But `bin` is very rarely empty.
        ## Until it is reasonable to require Dune >= 3.1.0, we keep this special
        ## case for the part of the CI interested in lower bounds.
        if: matrix.lower-bounds == 'lower-bounds'
        run: opam exec -- make uninstall || true

      - name: Try cleaning
        run: opam exec -- make clean

      - name: Build documentation for auto-deployment
        if: matrix.doc != 'no-doc'
        run: opam exec -- make doc

      - name: Upload documentation artifact
        if: matrix.doc != 'no-doc'
        uses: actions/upload-pages-artifact@v2
        with:
          path: doc/

      - name: Deploy to GitHub pages
        uses: actions/deploy-pages@v2
        if: github.event_name == 'push'
            && github.ref == 'refs/heads/main'
            && matrix.deploy-doc == 'deploy-doc'

  ## ========================= [ APT-based CI ] ========================== ##

  apt-based:

    runs-on: ubuntu-latest

    steps:
      - name: Install OCaml & dependencies
        run: |
          sudo apt-get install                                                 \
              build-essential ocaml dune menhir libmenhir-ocaml-dev            \
              libppx-deriving-yojson-ocaml-dev libppx-visitors-ocaml-dev       \
              libyojson-ocaml-dev

      - name: Checkout repository
        uses: actions/checkout@v4

      - name: Try building
        run: make

      ## No odoc in Debian stable, sadly, so no documentation!
      ## REVIEW: Ubuntu 22.10 does have a package `ocaml-odoc` though.

      # - name: Try building documentation
      #   run: make doc

      ## Ubuntu 22.10 only has Alcotest 1.6 which is not recent enough for our
      ## tests. Therefore, tests are disabled on this platform.

      # - name: Run tests
      #   run: make check

      - name: Try installing
        run: sudo make install

      - name: Try building examples
        run: make examples

      - name: Try uninstalling
        run: sudo make uninstall

      ## Not working (as of 2023-03-31), `dune clean` complains about:
      ##
      ##     Error: unlink: _build/default/.dune/configurator: Permission denied
      ##
      ## Maybe related to https://github.com/ocaml/dune/issues/3857.

      # - name: Try cleaning
      #   run: make clean

  ## ======================== [ Docker-based CI ] ======================== ##

  docker-based:

    strategy:
      fail-fast: false
      matrix:
        include:
          - {tag: alpine, deploy-image: deploy-image}
          - {tag: archlinux}
          - {tag: centos, tests: no-tests}  ## only has Alcotest 1.6 (as of 2023-05-11)
          - {tag: debian}
          - {tag: debian-testing}
          - {tag: debian-unstable}
          - {tag: fedora}
          - {tag: opensuse}
          - {tag: oraclelinux}
          - {tag: ubuntu}
          - {tag: ubuntu-lts}

    runs-on: ubuntu-latest

    steps:
      - name: Checkout repository
        uses: actions/checkout@v4

      - name: Build Docker image
        run: |
          docker build \
            --tag morbig \
            . \
            --build-arg tag=${{matrix.tag}} \
            --build-arg doc=${{matrix.doc != 'no-doc'}} \
            --build-arg tests=${{matrix.tests != 'no-tests'}}

      - name: Run tests
        run: |
          docker run --entrypoint /bin/sh morbig -c '
              set -e
              eval $(opam env)
              cd /home/opam/morbig
              if ${{ matrix.tests != 'no-tests' }}; then
                make check
              fi
              if ${{ matrix.doc != 'no-doc' }}; then
                make doc
              fi
              make install
              make examples
              make uninstall
          '

      - name: Login to Docker Hub
        if: github.event_name == 'push' && matrix.deploy-image == 'deploy-image'
        uses: docker/login-action@v2
        with:
          username: ${{ secrets.DOCKER_HUB_USERNAME }}
          password: ${{ secrets.DOCKER_HUB_ACCESS_TOKEN }}

      - name: Rename Docker image
        if: github.event_name == 'push' && matrix.deploy-image == 'deploy-image'
        run: docker image tag morbig colisanr/morbig:${GITHUB_REF##*/}

      - name: Push to Docker Hub
        if: github.event_name == 'push' && matrix.deploy-image == 'deploy-image'
        run: docker push colisanr/morbig:${GITHUB_REF##*/}

  ## ========================= [ Nix-based CI ] ========================== ##

  nix-based:

    strategy:
      fail-fast: false
      matrix:
        package:
          - with-nixpkgs
          - with-opam-nix

    runs-on: ubuntu-latest

    steps:
      - name: Checkout repository
        uses: actions/checkout@v4

      - name: Install Nix
        uses: cachix/install-nix-action@v22
        with:
          extra_nix_config: |
            ## Access token to avoid triggering GitHub's rate limiting.
            access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}

      - name: Install Nix dependencies
        run: |
          nix develop .#${{ matrix.package }} --print-build-logs --command true

      - name: Build in development Shell
        run: |
          nix develop .#${{ matrix.package }} --command make

      - name: Build documentation in development Shell
        run: |
          nix develop .#${{ matrix.package }} --command make doc

      - name: Run tests in development Shell
        run: |
          nix develop .#${{ matrix.package }} --command make check

      - name: Build with Nix
        run: |
          nix build .#${{ matrix.package }} --print-build-logs

  nix-flake-checks:
    runs-on: ubuntu-latest

    steps:
      - name: Checkout repository
        uses: actions/checkout@v4

      - name: Install Nix
        uses: cachix/install-nix-action@v22
        with:
          extra_nix_config: |
            ## Access token to avoid triggering GitHub's rate limiting.
            access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}

      - name: Run flake checks
        run: nix flake check . --print-build-logs