tests workflow (horejsek/python-fastjsonschema)

The tests workflow from horejsek/python-fastjsonschema, explained and optimized by Latchkey.

What it does

This is the tests workflow from the horejsek/python-fastjsonschema 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: tests

on: [push, pull_request, workflow_dispatch]

concurrency:
  group: >-
    ${{ github.workflow }}-
    ${{ github.ref_type }}-
    ${{ github.event.pull_request.number || github.sha }}
  cancel-in-progress: true

jobs:
  test:
    strategy:
      matrix:
        python:
        - "3.10" # oldest Python supported by PSF
        - "3.11"
        - "3.12"
        - "3.13"
        - "3.14"  # newest Python that is stable
        platform:
        - ubuntu-latest
        - macos-latest
        - windows-latest
    runs-on: ${{ matrix.platform }}
    steps:
      - uses: actions/checkout@v2
      - name: Setup Python
        uses: actions/setup-python@v2
        with:
          python-version: ${{ matrix.python }}
      - name: Run tests
        run: pipx run tox -e py -- -vvv

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: tests
 
on: [push, pull_request, workflow_dispatch]
 
concurrency:
  group: >-
    ${{ github.workflow }}-
    ${{ github.ref_type }}-
    ${{ github.event.pull_request.number || github.sha }}
  cancel-in-progress: true
 
jobs:
  test:
    timeout-minutes: 30
    strategy:
      matrix:
        python:
        - "3.10" # oldest Python supported by PSF
        - "3.11"
        - "3.12"
        - "3.13"
        - "3.14"  # newest Python that is stable
        platform:
        - ubuntu-latest
        - macos-latest
        - windows-latest
    runs-on: ${{ matrix.platform }}
    steps:
      - uses: actions/checkout@v2
      - name: Setup Python
        uses: actions/setup-python@v2
        with:
          cache: 'pip'
          python-version: ${{ matrix.python }}
      - name: Run tests
        run: pipx run tox -e py -- -vvv
 

What changed

• 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.

This workflow runs 1 job (15 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