Danger workflow (PrismJS/prism)

The Danger workflow from PrismJS/prism, explained and optimized by Latchkey.

What it does

This is the Danger workflow from the PrismJS/prism 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: Danger

on:
  pull_request_target:

jobs:
  run:
    runs-on: ubuntu-latest

    steps:
      - uses: actions/checkout@v6
        with:
          fetch-depth: 0
      # Pin Node 20 - Danger v13 uses node-fetch 2.x, which throws
      # `ERR_STREAM_PREMATURE_CLOSE` on gzip responses under newer Node.js
      # versions provided by the default `ubuntu-latest` runner image.
      - uses: actions/setup-node@v3
        with:
          node-version: 20.x
      # create a new branch called pr from the remote PR branch
      - run: git remote add pr_repo $PR_URL && git fetch pr_repo $PR_REF && git branch pr pr_repo/$PR_REF
        env:
          PR_URL: ${{github.event.pull_request.head.repo.clone_url}}
          PR_REF: ${{github.event.pull_request.head.ref}}
      - run: npm ci
      - name: Danger
        run: npx danger ci
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

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: Danger
 
on:
  pull_request_target:
 
jobs:
  run:
    timeout-minutes: 30
    runs-on: latchkey-small
 
    steps:
      - uses: actions/checkout@v6
        with:
          fetch-depth: 0
      # Pin Node 20 - Danger v13 uses node-fetch 2.x, which throws
      # `ERR_STREAM_PREMATURE_CLOSE` on gzip responses under newer Node.js
      # versions provided by the default `ubuntu-latest` runner image.
      - uses: actions/setup-node@v3
        with:
          cache: 'npm'
          node-version: 20.x
      # create a new branch called pr from the remote PR branch
      - run: git remote add pr_repo $PR_URL && git fetch pr_repo $PR_REF && git branch pr pr_repo/$PR_REF
        env:
          PR_URL: ${{github.event.pull_request.head.repo.clone_url}}
          PR_REF: ${{github.event.pull_request.head.ref}}
      - run: npm ci
      - name: Danger
        run: npx danger ci
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
 

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.
• 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 per trigger. On Latchkey the same minutes cost up to 58% less than GitHub-hosted, with zero queue time.

Actions used in this workflow