Development Setup

Complete guide to setting up your development environment for WP Kernel.

🚨 TL;DR - Quick Start

👉 Runbook - Common development tasks and workflows.

For experienced developers who want the critical information fast, read that first. This page has the complete, detailed setup instructions.

Prerequisites

Required Software

Install these tools before proceeding:

Node.js (v22.20.0 LTS)

Use nvm for version management:

# Install nvm (if not already installed)
curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.0/install.sh | bash

# Install Node 22
nvm install 22.20.0
nvm use 22.20.0
nvm alias default 22.20.0

# Verify
node --version  # Should show v22.20.0

pnpm (v9.12.3+)

npm install -g pnpm

# Verify
pnpm --version  # Should show 9.12.3 or later

Docker Desktop

Download and install from docker.com/products/docker-desktop.

# Verify
docker --version  # Should show 20.10+ or later

Git

# macOS (via Homebrew)
brew install git

# Verify
git --version

Repository Setup

Clone and Install

# Clone the repository
git clone https://github.com/theGeekist/wp-kernel.git
cd wp-kernel

# Install dependencies (this may take a few minutes)
pnpm install

Verify Installation

# Build all packages
pnpm build

# Run lint
pnpm lint

# Expected output: zero errors

WordPress Environment

WP Kernel uses @wordpress/env for local WordPress instances.

Two Environments

1. Development (localhost:8888) - For manual testing
2. Testing (localhost:8889) - For E2E tests with fixtures

Start WordPress

Quick Start (Recommended)

Start WordPress with seed data:

pnpm wp:fresh

This command:

1. Starts Docker containers
2. Seeds test users, applications, and jobs
3. Activates the showcase plugin

Manual Start

# Start without seed data
pnpm wp:start

# Seed data separately
pnpm wp:seed

Access WordPress

• Development Site: http://localhost:8888
• Admin Dashboard: http://localhost:8888/wp-admin
• Testing Site: http://localhost:8889
• Credentials: admin / password

Stop WordPress

pnpm wp:stop

Reset WordPress

If you need a clean slate:

# Stop and destroy all data
pnpm wp:destroy

# Start fresh
pnpm wp:fresh

Development Workflow

Terminal Setup

Open three terminal windows/tabs:

Terminal 1: Watch Build

pnpm dev

This watches all packages and rebuilds on file changes.

Terminal 2: WordPress

pnpm wp:start

Keep WordPress running for manual testing.

Terminal 3: Tests

# Unit tests (watch mode)
pnpm test --watch

# Or run once
pnpm test

# E2E tests (WordPress must be running)
pnpm e2e

Making Changes

1. Create a branch:

   git checkout -b feature/my-feature

2. Make changes: Edit files in packages/*/src/

3. Verify builds: Watch terminal 1 for build errors

4. Write tests: Add tests for new functionality

5. Run tests:

   pnpm test        # Unit tests
   pnpm e2e         # E2E tests
   pnpm test:coverage  # With coverage

6. Lint:

   pnpm lint        # Check
   pnpm lint:fix    # Auto-fix

7. Update CHANGELOG.md:

   Add entry to affected packages' CHANGELOG.md:

   ## 0.x.0 [Unreleased]
   
   ### Added
   
   - Custom invalidation support for resources

8. Commit:

   git add .
   git commit -m "feat(resources): add custom invalidation"

9. Push and PR:

   git push origin feature/my-feature
   # Open PR on GitHub

Package Structure

packages/
├── kernel/              # Core framework
│   ├── src/
│   │   ├── resource/    # Resources
│   │   ├── actions/     # Actions
│   │   ├── events/      # Events
│   │   └── index.ts
│   └── package.json
├── ui/                  # UI components
│   ├── src/
│   └── package.json
├── e2e-utils/           # Test utilities
│   ├── src/
│   └── package.json
└── showcase-plugin/     # Example plugin
    ├── app/             # Application code
    │   ├── resources/
    │   ├── actions/
    │   ├── views/
    │   └── jobs/
    └── includes/        # PHP code

Environment Variables

CI Flag

Set CI=true to run in CI mode (affects Playwright webServer):

export CI=true
pnpm e2e

Node Version

Ensure you're using Node 22:

node --version  # Should be v22.20.0

If not, use nvm:

nvm use 22

IDE Setup

VS Code (Recommended)

Install these extensions:

• ESLint (dbaeumer.vscode-eslint)
• Prettier (esbenp.prettier-vscode)
• TypeScript (ms-vscode.vscode-typescript-next)
• WordPress Snippets (wordpresstoolbox.wordpress-toolbox)

Settings

Create .vscode/settings.json:

{
	"editor.formatOnSave": true,
	"editor.defaultFormatter": "esbenp.prettier-vscode",
	"editor.codeActionsOnSave": {
		"source.fixAll.eslint": true
	},
	"typescript.tsdk": "node_modules/typescript/lib",
	"eslint.workingDirectories": [{ "pattern": "packages/*" }]
}

Troubleshooting

Port Conflicts

If ports 8888 or 8889 are already in use:

# Find what's using the port
lsof -i :8888

# Kill the process
kill -9 <PID>

# Or use different ports (edit .wp-env.json)

Docker Issues

# Restart Docker Desktop

# Or reset wp-env
pnpm wp:destroy
pnpm wp:fresh

Build Errors

# Clean and reinstall
rm -rf node_modules pnpm-lock.yaml
pnpm install
pnpm build

Test Failures

# Reset test environment
pnpm wp:seed:reset
pnpm e2e

Next Steps

Now that your environment is set up:

• Runbook - Common development tasks
• Coding Standards - Style guide
• Testing - Writing tests
• Pull Requests - Submitting changes