lint.yaml

name: Lint

on:
  push:
    branches:
      - main
  pull_request:

concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true

jobs:
  lint:
    name: Run pre-commit & flake8
    runs-on: ubuntu-latest
    env:
      # Configure pip to cache dependencies and do a user install
      PIP_NO_CACHE_DIR: false
      PIP_USER: 1

      # Make sure package manager does not use virtualenv
      POETRY_VIRTUALENVS_CREATE: false

      # Specify explicit paths for python dependencies and the pre-commit
      # environment so we know which directories to cache
      POETRY_CACHE_DIR: ${{ github.workspace }}/.cache/py-user-base
      PYTHONUSERBASE: ${{ github.workspace }}/.cache/py-user-base
      PRE_COMMIT_HOME: ${{ github.workspace }}/.cache/pre-commit-cache

    steps:
      - name: Add custom PYTHONUSERBASE to PATH
        run: echo '${{ env.PYTHONUSERBASE }}/bin/' >> $GITHUB_PATH

      - name: Checkout repository
        uses: actions/checkout@v2

      - name: Setup python
        id: python
        uses: actions/setup-python@v2
        with:
          python-version: '3.9.5'

      # This step caches our Python dependencies. To make sure we
      # only restore a cache when the dependencies, the python version,
      # the runner operating system, and the dependency location haven't
      # changed, we create a cache key that is a composite of those states.
      #
      # Only when the context is exactly the same, we will restore the cache.
      - name: Python Dependency Caching
        uses: actions/cache@v2
        id: python_cache
        with:
          path: ${{ env.PYTHONUSERBASE }}
          key: "python-0-${{ runner.os }}-${{ env.PYTHONUSERBASE }}-\
          ${{ steps.python.outputs.python-version }}-\
          ${{ hashFiles('./pyproject.toml', './poetry.lock') }}"

      # Install our dependencies if we did not restore a dependency cache
      - name: Install dependencies using Poetry
        if: steps.python_cache.outputs.cache-hit != 'true'
        run: |
          pip install poetry
          poetry install
      # This step caches our pre-commit environment. To make sure we
      # do create a new environment when our pre-commit setup changes,
      # we create a cache key based on relevant factors.
      - name: Pre-commit Environment Caching
        uses: actions/cache@v2
        with:
          path: ${{ env.PRE_COMMIT_HOME }}
          key: "precommit-0-${{ runner.os }}-${{ env.PRE_COMMIT_HOME }}-\
          ${{ steps.python.outputs.python-version }}-\
          ${{ hashFiles('./.pre-commit-config.yaml') }}"

      # We will not run `flake8` here, as we will use a separate flake8
      # action. As pre-commit does not support user installs, we set
      # PIP_USER=0 to not do a user install.
      - name: Run pre-commit hooks
        run: export PIP_USER=0; pre-commit run --all-files