name: CI

on:
  pull_request:
  push:
    branches:
      - master

jobs:
  test:
    runs-on: ubuntu-16.04
    env:
      MIX_ENV: test
      GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
    strategy:
      fail-fast: false
      matrix:
        include:
          - pair:
              elixir: 1.9.4
              otp: 20.3.1
          - pair:
              elixir: 1.11.1
              otp: 21.3
          - pair:
              elixir: 1.10.4
              otp: 22.2
          - pair:
              elixir: 1.11.3
              otp: 22.2
          - pair:
              elixir: 1.11.3
              otp: 23.2.5
            lint: lint
    steps:
      - uses: actions/checkout@v2

      - uses: erlef/setup-elixir@v1
        with:
          otp-version: ${{matrix.pair.otp}}
          elixir-version: ${{matrix.pair.elixir}}

      - name: Install Dependencies
        run: mix deps.get --only test

      - run: mix format --check-formatted
        if: ${{ matrix.lint }}

      - run: mix deps.get && mix deps.unlock --check-unused
        if: ${{ matrix.lint }}

      - run: mix deps.compile

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

      - run: mix coveralls.github

      - name: Retrieve PLT Cache
        uses: actions/cache@v1
        id: plt-cache
        with:
          path: priv/plts
          key: ${{ runner.os }}-${{ matrix.pair.otp }}-${{ matrix.pair.elixir }}-plts-${{ hashFiles(format('{0}{1}', github.workspace, '/mix.lock')) }}

      - name: Create PLTs
        if: steps.plt-cache.outputs.cache-hit != 'true'
        run: |
          mkdir -p priv/plts
          mix dialyzer --plt

      - name: Run dialyzer
        run: mix dialyzer --no-check --halt-exit-status