Test the code workflow (CERT-Polska/karton)

The Test the code workflow from CERT-Polska/karton, explained and optimized by Latchkey.

What it does

This is the Test the code workflow from the CERT-Polska/karton repository, a real project running GitHub Actions. It is shown here with attribution under its BSD-3-Clause license.

Below, Latchkey shows a faster, safer version produced by its optimization engine.

The workflow

name: Test the code
on:
  push:
    branches:
      - master
  pull_request:
    branches:
      - master
jobs:
  lint:
    runs-on: ubuntu-latest
    steps:
      - uses: CERT-Polska/lint-python-action@v2
        with:
          source: karton/
          python-version: 3.12
  unittest:
    runs-on: ubuntu-latest
    strategy:
      matrix:
        minor: [10, 11, 12, 13]
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-python@v5
        with:
          python-version: 3.${{ matrix.minor }}
      - run: pip install -r requirements.txt
      - run: python -m unittest discover tests/unit
  e2etest:
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@v7
    - name: Run tests
      run: docker compose -f tests/e2e/docker-compose.yml up --build --exit-code-from pytest
  docs:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v7
      - name: Set up Python 3.11
        uses: actions/setup-python@v5
        with:
          python-version: "3.11"
      - name: Install Karton
        run: pip install .
      - name: Install docs dependencies
        working-directory: docs
        run: pip install -r requirements.txt
      - name: Build docs
        working-directory: docs
        run: make html

The same workflow, on Latchkey

Estimated ~20% faster on cache hits, plus fewer wasted runs and a safer supply chain. Added and changed lines are highlighted.

name: Test the code
on:
  push:
    branches:
      - master
  pull_request:
    branches:
      - master
concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true
 
jobs:
  lint:
    timeout-minutes: 30
    runs-on: latchkey-small
    steps:
      - uses: CERT-Polska/lint-python-action@v2
        with:
          source: karton/
          python-version: 3.12
  unittest:
    timeout-minutes: 30
    runs-on: latchkey-small
    strategy:
      matrix:
        minor: [10, 11, 12, 13]
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-python@v5
        with:
          cache: 'pip'
          python-version: 3.${{ matrix.minor }}
      - run: pip install -r requirements.txt
      - run: python -m unittest discover tests/unit
  e2etest:
    timeout-minutes: 30
    runs-on: latchkey-small
    steps:
    - uses: actions/checkout@v7
    - name: Run tests
      run: docker compose -f tests/e2e/docker-compose.yml up --build --exit-code-from pytest
  docs:
    timeout-minutes: 30
    runs-on: latchkey-small
    steps:
      - uses: actions/checkout@v7
      - name: Set up Python 3.11
        uses: actions/setup-python@v5
        with:
          cache: 'pip'
          python-version: "3.11"
      - name: Install Karton
        run: pip install .
      - name: Install docs dependencies
        working-directory: docs
        run: pip install -r requirements.txt
      - name: Build docs
        working-directory: docs
        run: make html
 

What changed

• Run on Latchkey managed runners with one line (runs-on), which apply the fixes below automatically and self-heal transient failures. This example uses latchkey-small; pick the runner size that fits the job.
• Cancel superseded runs when a branch or PR gets a newer push.
• Cache dependency installs on the setup step so they are served from cache.
• Add a job timeout so a hung step cannot burn hours of runner time.

1 third-party action is referenced by a movable tag. Pin it to the commit SHA (Latchkey resolves and applies this automatically) so a repointed tag cannot change what runs.

What Latchkey heals here

This workflow has steps that commonly fail on transient issues (network, registries, flaky browsers). On Latchkey managed runners they are detected, retried, and self-healed instead of failing your build:

• Dependency installs
• End-to-end and browser tests

This workflow runs 4 jobs (7 with the matrix expanded) per trigger. On Latchkey the same minutes cost up to 58% less than GitHub-hosted, with zero queue time.

Actions used in this workflow