name: Test

on: [push, pull_request]

jobs:
  build:
    # We want to run on external PRs, but not on our own internal PRs as they'll be run
    # by the push to the branch. Without this if check, checks are duplicated since
    # internal PRs match both the push and pull_request events.
    if:
      github.event_name == 'push' || github.event.pull_request.head.repo.full_name !=
      github.repository

    runs-on: ${{ matrix.os }}
    strategy:
      fail-fast: false
      matrix:
        python-version: [3.6, 3.7, 3.8, 3.9]
        os: [ubuntu-latest, macOS-latest, windows-latest]

    steps:
      - uses: actions/checkout@v2

      - name: Set up Python ${{ matrix.python-version }}
        uses: actions/setup-python@v2
        with:
          python-version: ${{ matrix.python-version }}

      - name: Install dependencies
        run: |
          python -m pip install --upgrade pip
          python -m pip install --upgrade tox

      - name: Unit tests
        run: |
          tox -e py