Run Tests workflow (jmespath/jmespath.py)

The Run Tests workflow from jmespath/jmespath.py, explained and optimized by Latchkey.

What it does

This is the Run Tests workflow from the jmespath/jmespath.py repository, a real project running GitHub Actions. It is shown here with attribution under its MIT license.

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

The workflow

name: Run Tests

on: [push, pull_request]

permissions:
  contents: read

jobs:
  build:

    runs-on: ${{ matrix.os }}
    strategy:
      fail-fast: false
      matrix:
        os: [ubuntu-latest, macOS-latest, windows-latest]
        python-version: ["3.9", "3.10", "3.11", "3.12", "3.13", "3.14"]

    steps:
    - uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3
    - name: Set up Python ${{ matrix.python-version }}
      uses: actions/setup-python@83679a892e2d95755f2dac6acb0bfd1e9ac5d548
      with:
        python-version: ${{ matrix.python-version }}
    - name: Install dependencies
      run: |
        pip install pip==25.1.0
        pip install -r requirements.txt
        python -m pip install .
    - name: Test with pytest
      run: |
        cd tests/ && python -m pytest --cov jmespath --cov-report term-missing

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: Run Tests
 
on: [push, pull_request]
 
permissions:
  contents: read
 
concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true
 
jobs:
  build:
    timeout-minutes: 30
 
    runs-on: ${{ matrix.os }}
    strategy:
      fail-fast: false
      matrix:
        os: [ubuntu-latest, macOS-latest, windows-latest]
        python-version: ["3.9", "3.10", "3.11", "3.12", "3.13", "3.14"]
 
    steps:
    - uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3
    - name: Set up Python ${{ matrix.python-version }}
      uses: actions/setup-python@83679a892e2d95755f2dac6acb0bfd1e9ac5d548
      with:
        cache: 'pip'
        python-version: ${{ matrix.python-version }}
    - name: Install dependencies
      run: |
        pip install pip==25.1.0
        pip install -r requirements.txt
        python -m pip install .
    - name: Test with pytest
      run: |
        cd tests/ && python -m pytest --cov jmespath --cov-report term-missing
 
 

What changed

• Cancel superseded runs when a branch or PR gets a newer push.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.

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

This workflow runs 1 job (18 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