ESLint CI workflow (codecombat/codecombat)

The ESLint CI workflow from codecombat/codecombat, explained and optimized by Latchkey.

What it does

This is the ESLint CI workflow from the codecombat/codecombat 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: ESLint CI

# Triggering workflow on all push
on: [pull_request]

permissions:
  contents: read

jobs:
  build:
    name: ESLint CI

    runs-on: ubuntu-latest

    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 2

      - uses: actions/setup-node@v4
        with:
          node-version: 22.22.1
          cache: 'npm'

      - name: Install dependencies
        run: CYPRESS_INSTALL_BINARY=0 npm ci  # OR: yarn

      - name: Fetch the base branch, so we can use `git diff`
        run: git fetch origin ${{ github.event.pull_request.base.sha }}:${{ github.event.pull_request.base.sha }}

      - name: Fetch the head branch, so we can use `git diff`
        run: git fetch origin ${{ github.event.pull_request.head.sha }}:${{ github.event.pull_request.head.sha }}

      - name: Run eslint on changed files
        run: npx @automattic/eslint-changed --git --git-base ${{ github.event.pull_request.base.sha }} --in-diff-only --debug --ext .js,.vue

The same workflow, on Latchkey

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

name: ESLint CI
 
# Triggering workflow on all push
on: [pull_request]
 
permissions:
  contents: read
 
concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true
 
jobs:
  build:
    timeout-minutes: 30
    name: ESLint CI
 
    runs-on: latchkey-small
 
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 2
 
      - uses: actions/setup-node@v4
        with:
          node-version: 22.22.1
          cache: 'npm'
 
      - name: Install dependencies
        run: CYPRESS_INSTALL_BINARY=0 npm ci  # OR: yarn
 
      - name: Fetch the base branch, so we can use `git diff`
        run: git fetch origin ${{ github.event.pull_request.base.sha }}:${{ github.event.pull_request.base.sha }}
 
      - name: Fetch the head branch, so we can use `git diff`
        run: git fetch origin ${{ github.event.pull_request.head.sha }}:${{ github.event.pull_request.head.sha }}
 
      - name: Run eslint on changed files
        run: npx @automattic/eslint-changed --git --git-base ${{ github.event.pull_request.base.sha }} --in-diff-only --debug --ext .js,.vue
 

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.

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