Test workflow (immerjs/immer)

The Test workflow from immerjs/immer, explained and optimized by Latchkey.

What it does

This is the Test workflow from the immerjs/immer 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

# This workflow will do a clean install of node dependencies, cache/restore them, build the source code and run tests across different versions of node
# For more information see: https://help.github.com/actions/language-and-framework-guides/using-nodejs-with-github-actions

name: Test

on: ["push", "pull_request"]

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v6
        with:
          node-version: 24
      - name: yarn install
        run: yarn --frozen-lockfile
      - name: test
        run: yarn test
      - name: coverage test
        run: yarn coverage
      - name: perf test
        run: yarn test:perf
      - uses: coverallsapp/github-action@v1.1.2
        with:
          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.

# This workflow will do a clean install of node dependencies, cache/restore them, build the source code and run tests across different versions of node
# For more information see: https://help.github.com/actions/language-and-framework-guides/using-nodejs-with-github-actions
 
name: Test
 
on: ["push", "pull_request"]
 
concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true
 
jobs:
  build:
    timeout-minutes: 30
    runs-on: latchkey-small
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v6
        with:
          cache: 'npm'
          node-version: 24
      - name: yarn install
        run: yarn --frozen-lockfile
      - name: test
        run: yarn test
      - name: coverage test
        run: yarn coverage
      - name: perf test
        run: yarn test:perf
      - uses: coverallsapp/github-action@v1.1.2
        with:
          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.
• 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.

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