CI workflow (miracle2k/webassets)

The CI workflow from miracle2k/webassets, explained and optimized by Latchkey.

What it does

This is the CI workflow from the miracle2k/webassets repository, a real project running GitHub Actions. It is shown here with attribution under its BSD-2-Clause license.

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

The workflow

---
name: CI

on:
  merge_group:
  push:
    branches: [master, main, ci-*]
    tags: ["*"]
  pull_request:
  workflow_dispatch:

env:
  FORCE_COLOR: "1"
  PIP_DISABLE_PIP_VERSION_CHECK: "1"
  PIP_NO_PYTHON_VERSION_WARNING: "1"

permissions: {}

jobs:
  tests:
    strategy:
      fail-fast: false
      matrix:
        python-version:
          - "3.10"
          - "3.11"
          - "3.12"
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          cache: 'npm'
          cache-dependency-path: package-lock.json
      - uses: hynek/setup-cached-uv@v2
      - run: |
          npm install
          echo "$(pwd)/node_modules/.bin" >> "$GITHUB_PATH"

      - name: Prepare tox
        run: |
          V=${{ matrix.python-version }}
          echo TOX_PYTHON=py"$(echo $V | tr -d '.')" >>"$GITHUB_ENV"

      - run: >
          uvx --with=tox-uv
          tox run
          -e ${{ env.TOX_PYTHON }}

The same workflow, on Latchkey

Removes redundant runs and caps runaway jobs. Added and changed lines are highlighted.

---
name: CI
 
on:
  merge_group:
  push:
    branches: [master, main, ci-*]
    tags: ["*"]
  pull_request:
  workflow_dispatch:
 
env:
  FORCE_COLOR: "1"
  PIP_DISABLE_PIP_VERSION_CHECK: "1"
  PIP_NO_PYTHON_VERSION_WARNING: "1"
 
permissions: {}
 
concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true
 
jobs:
  tests:
    timeout-minutes: 30
    strategy:
      fail-fast: false
      matrix:
        python-version:
          - "3.10"
          - "3.11"
          - "3.12"
    runs-on: latchkey-small
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          cache: 'npm'
          cache-dependency-path: package-lock.json
      - uses: hynek/setup-cached-uv@v2
      - run: |
          npm install
          echo "$(pwd)/node_modules/.bin" >> "$GITHUB_PATH"
 
      - name: Prepare tox
        run: |
          V=${{ matrix.python-version }}
          echo TOX_PYTHON=py"$(echo $V | tr -d '.')" >>"$GITHUB_ENV"
 
      - run: >
          uvx --with=tox-uv
          tox run
          -e ${{ env.TOX_PYTHON }}
 

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.
• 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

This workflow runs 1 job (3 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