name: Lint & Test

on:
  push:
    branches:
      - main
  pull_request:


jobs:
  lint-test:
    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'

      # Start the database early to give it a chance to get ready before
      # we start running tests.
      - name: Run database using docker-compose
        run: docker-compose run -d -p 7777:5432 --name pydis_web postgres

      # 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; SKIP=flake8 pre-commit run --all-files

      # Run flake8 and have it format the linting errors in the format of
      # the GitHub Workflow command to register error annotations. This
      # means that our flake8 output is automatically added as an error
      # annotation to both the run result and in the "Files" tab of a
      # pull request.
      #
      # Format used:
      # ::error file={filename},line={line},col={col}::{message}
      - name: Run flake8
        run: "flake8 \
        --format='::error file=%(path)s,line=%(row)d,col=%(col)d::\
        [flake8] %(code)s: %(text)s'"

      - name: Migrations and run tests with coverage.py
        run: |
          python manage.py makemigrations --check
          python manage.py migrate
          coverage run manage.py test --no-input
          coverage report -m
        env:
          CI: True
          DATABASE_URL: postgres://pysite:pysite@localhost:7777/pysite
          METRICITY_DB_URL: postgres://pysite:pysite@localhost:7777/metricity

      # This step will publish the coverage reports coveralls.io and
      # print a "job" link in the output of the GitHub Action
      - name: Publish coverage report to coveralls.io
        env:
            GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: coveralls

      - name: Tear down docker-compose containers
        run: docker-compose stop
        if: ${{ always() }}

      # Prepare the Pull Request Payload artifact. If this fails, we
      # we fail silently using the `continue-on-error` option. It's
      # nice if this succeeds, but if it fails for any reason, it
      # does not mean that our lint-test checks failed.
      - name: Prepare Pull Request Payload artifact
        id: prepare-artifact
        if: always() && github.event_name == 'pull_request'
        continue-on-error: true
        run: cat $GITHUB_EVENT_PATH | jq '.pull_request' > pull_request_payload.json

      # This only makes sense if the previous step succeeded. To
      # get the original outcome of the previous step before the
      # `continue-on-error` conclusion is applied, we use the
      # `.outcome` value. This step also fails silently.
      - name: Upload a Build Artifact
        if: always() && steps.prepare-artifact.outcome == 'success'
        continue-on-error: true
        uses: actions/upload-artifact@v2
        with:
          name: pull-request-payload
          path: pull_request_payload.json