Test workflow (ianare/exif-py)

The Test workflow from ianare/exif-py, explained and optimized by Latchkey.

What it does

This is the Test workflow from the ianare/exif-py 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

#
# Run unit tests.
#
name: Test

on:
  - push
  - workflow_dispatch

jobs:
  pytest:
    name: Run Tests
    runs-on: ubuntu-22.04
    timeout-minutes: 30
    strategy:
      matrix:
        python-version:
          - "3.7"
          - "3.8"
          - "3.9"
          - "3.10"
          - "3.11"
          - "3.12"
          - "3.13"
          - "3.14"
    steps:
    - uses: actions/checkout@v4

    - name: Set up Python ${{ matrix.python-version }}
      uses: actions/setup-python@v4
      with:
        python-version: ${{ matrix.python-version }}

    - name: Cache dependencies
      uses: actions/cache@v4
      with:
        path: ~/.cache/pip
        key: ${{ runner.os }}-test-${{ hashFiles('setup.py') }}
        restore-keys: |
          ${{ runner.os }}-test-

    - name: Install
      run: |
        pip install virtualenv
        make venv install-test

    - name: Run in debug and color mode
      run: |
        source .venv/bin/activate
        make test-cli

    - name: Compare image processing output
      run: |
        source .venv/bin/activate
        make test-diff

    - name: Run pytest
      run: |
        source .venv/bin/activate
        make test-pytest

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.

#
# Run unit tests.
#
name: Test
 
on:
  - push
  - workflow_dispatch
 
concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true
 
jobs:
  pytest:
    name: Run Tests
    runs-on: latchkey-small
    timeout-minutes: 30
    strategy:
      matrix:
        python-version:
          - "3.7"
          - "3.8"
          - "3.9"
          - "3.10"
          - "3.11"
          - "3.12"
          - "3.13"
          - "3.14"
    steps:
    - uses: actions/checkout@v4
 
    - name: Set up Python ${{ matrix.python-version }}
      uses: actions/setup-python@v4
      with:
        cache: 'pip'
        python-version: ${{ matrix.python-version }}
 
    - name: Cache dependencies
      uses: actions/cache@v4
      with:
        path: ~/.cache/pip
        key: ${{ runner.os }}-test-${{ hashFiles('setup.py') }}
        restore-keys: |
          ${{ runner.os }}-test-
 
    - name: Install
      run: |
        pip install virtualenv
        make venv install-test
 
    - name: Run in debug and color mode
      run: |
        source .venv/bin/activate
        make test-cli
 
    - name: Compare image processing output
      run: |
        source .venv/bin/activate
        make test-diff
 
    - name: Run pytest
      run: |
        source .venv/bin/activate
        make test-pytest
 

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.

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 (8 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