CI workflow (polyanskiy/refractiveindex.info-database)

The CI workflow from polyanskiy/refractiveindex.info-database, explained and optimized by Latchkey.

What it does

This is the CI workflow from the polyanskiy/refractiveindex.info-database repository, a real project running GitHub Actions. It is shown here with attribution under its CC0-1.0 license.

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

The workflow

# This `test.yml` file defines a GitHub action that will run for all pull requests,
# and for all pushes to dev. It installs the python test libraries and then runs the `pytest` command.
# This automatically detects `test_*.py` files and executes tests therein.

name: CI

on:
  pull_request:
  push:
    branches:
      - develop
  # schedule:
  #     - cron: "0 13 * * 1"  # Every Monday at 9AM EST

jobs:
  test-parsing:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout repository
        uses: actions/checkout@v6

      - name: Install uv
        uses: astral-sh/setup-uv@v7

      - name: "Set up Python"
        uses: actions/setup-python@v6
        with:
          python-version-file: "pyproject.toml"

      - name: Install the project
        run: uv sync --all-extras --dev

      - name: Run tests
        run: uv run pytest tests

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.

# This `test.yml` file defines a GitHub action that will run for all pull requests,
# and for all pushes to dev. It installs the python test libraries and then runs the `pytest` command.
# This automatically detects `test_*.py` files and executes tests therein.
 
name: CI
 
on:
  pull_request:
  push:
    branches:
      - develop
  # schedule:
  #     - cron: "0 13 * * 1"  # Every Monday at 9AM EST
 
concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true
 
jobs:
  test-parsing:
    timeout-minutes: 30
    runs-on: latchkey-small
    steps:
      - name: Checkout repository
        uses: actions/checkout@v6
 
      - name: Install uv
        uses: astral-sh/setup-uv@v7
 
      - name: "Set up Python"
        uses: actions/setup-python@v6
        with:
          cache: 'pip'
          python-version-file: "pyproject.toml"
 
      - name: Install the project
        run: uv sync --all-extras --dev
 
      - name: Run tests
        run: uv run pytest tests
 

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.

This workflow runs 1 job per trigger. On Latchkey the same minutes cost up to 58% less than GitHub-hosted, with zero queue time.

Actions used in this workflow