main.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:
          # Latest versions
          - pair:
              elixir: "1.16"
              otp: "26.2"
            lint: lint
            coverage: true

          # Oldest supported versions
          - pair:
              elixir: "1.9.4"
              otp: "20.3.8"
    steps:
      - name: Check out this repository
        uses: actions/checkout@v3

      - name: Install Erlang/OTP and Elixir
        uses: erlef/setup-beam@v1
        with:
          otp-version: ${{ matrix.pair.otp }}
          elixir-version: ${{ matrix.pair.elixir }}
          version-type: strict

      - name: Cache Mix dependencies
        uses: actions/cache@v3
        with:
          path: |
            deps
            _build
          key: |
            ${{ runner.os }}-mix-${{ matrix.pair.elixir }}-${{ matrix.pair.otp }}-${{ hashFiles('**/mix.lock') }}
          restore-keys: |
            ${{ runner.os }}-mix-${{ matrix.pair.elixir }}-${{ matrix.pair.otp }}-

      - name: Fetch Mix dependencies (and check mix.lock)
        run: mix deps.get --check-locked

      - 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: Compile Mix dependencies
        run: mix deps.compile

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

      - run: mix test
        if: ${{ !matrix.coverage }}

      - run: mix coveralls.github
        if: ${{ matrix.coverage }}