ci.yml

name: CI

on:
  pull_request:
  push:
    branches:
      - main

jobs:
  test:
    runs-on: ubuntu-20.04
    env:
      MIX_ENV: test
      GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

    strategy:
      fail-fast: false
      matrix:
        include:
          - pair:
              elixir: 1.11
              otp: 21
          - pair:
              elixir: 1.17
              otp: 27
            lint: lint
            coverage: coverage
    steps:
      - name: Check out this repository
        uses: actions/checkout@v4

      - name: Set up Erlang and Elixir
        uses: erlef/setup-beam@v1
        with:
          otp-version: ${{ matrix.pair.otp }}
          elixir-version: ${{ matrix.pair.elixir }}

      - name: Restored cached Mix dependencies (downloaded and compiled)
        uses: actions/cache/restore@v4
        id: restore-mix-deps-cache
        with:
          path: |
            deps
            _build
          key: |
            ${{ runner.os }}-mix-${{ matrix.pair.elixir }}-${{ matrix.pair.otp }}-${{ hashFiles('**/mix.lock') }}-${{ github.run_id }}
            restore-keys: |
            ${{ runner.os }}-mix-${{ matrix.pair.elixir }}-${{ matrix.pair.otp }}-${{ hashFiles('**/mix.lock') }}-
            ${{ runner.os }}-mix-${{ matrix.pair.elixir }}-${{ matrix.pair.otp }}-

      - name: Fetch and compile Mix dependencies
        run: mix do deps.get --check-locked, deps.compile

      - name: Cache compiled Mix dependencies
        uses: actions/cache/save@v4
        with:
          path: |
            deps
            _build
          key: ${{ steps.restore-mix-deps-cache.outputs.cache-primary-key }}

      - name: Check for formatted files
        run: mix format --check-formatted
        if: ${{ matrix.lint }}

      - name: Check for unused dependencies
        run: mix deps.unlock --check-unused
        if: ${{ matrix.lint }}

      - name: Check compilation warnings
        run: mix compile --warnings-as-errors
        if: ${{ matrix.lint }}

      # We always need to run tests because code coverage forces us to skip some
      # tests, so better to run normal tests on the whole matrix and the coverage
      # only on the latest version.
      - name: Run tests
        run: mix test

      - name: Run tests with coverage
        if: ${{ matrix.coverage }}
        run: mix coveralls.github --exclude fails_on_coverage