Development Environment Setup

# Install nvm
curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.0/install.sh | bash

# Reload shell configuration
source ~/.bashrc  # or ~/.zshrc for zsh

# Verify installation
nvm --version

# From the project directory
nvm install

# Verify installation
node --version
npm --version

brew install watchman

# Ubuntu/Debian
sudo apt-get install watchman

# Or build from source
# See: https://facebook.github.io/watchman/docs/install.html

# Clone the repo
git clone https://github.com/Expensify/App.git
cd App

# Install dependencies
npm install

npm run web

# Create .env file
echo "USE_WEB_PROXY=true" > .env

# Run the app
npm run web

Access to fetch at 'https://www.expensify.com/api/BeginSignIn' 
from origin 'http://localhost:8080' has been blocked by CORS policy

# Kill process on port 8080
lsof -ti:8080 | xargs kill -9

# Or use a different port
PORT=8081 npm run web

# Install iOS dependencies
cd ios
pod install
cd ..

npm run ios

# Or specify a device
npm run ios -- --simulator="iPhone 15 Pro"

# Clean pod cache
cd ios
pod deintegrate
pod install --repo-update
cd ..

# Clean build
cd ios
xcodebuild clean
cd ..

# Remove derived data
rm -rf ~/Library/Developer/Xcode/DerivedData

# Reinstall dependencies
npm run clean
npm install
cd ios && pod install && cd ..

# Reset simulator
xcrun simctl erase all

# Or open Xcode and reset from menu:
# Device > Erase All Content and Settings

export ANDROID_HOME=$HOME/Library/Android/sdk  # macOS
# or
export ANDROID_HOME=$HOME/Android/Sdk  # Linux

export PATH=$PATH:$ANDROID_HOME/emulator
export PATH=$PATH:$ANDROID_HOME/platform-tools

source ~/.bashrc  # or ~/.zshrc

# Start emulator (from Android Studio or command line)
emulator -avd Pixel_6_API_34 &

# Run app
npm run android

# Clean gradle build
cd android
./gradlew clean
cd ..

# Clear metro cache
npm start -- --reset-cache

adb kill-server
adb start-server
adb devices

# List available AVDs
emulator -list-avds

# Start specific AVD
emulator -avd <avd_name>

# Cold boot (slower but more reliable)
emulator -avd <avd_name> -no-snapshot-load

# Kill metro bundler
lsof -ti:8081 | xargs kill -9

# Restart
npm start

npm run macos

// .vscode/extensions.json
{
  "recommendations": [
    "dbaeumer.vscode-eslint",
    "esbenp.prettier-vscode",
    "bradlc.vscode-tailwindcss",
    "ms-vscode.vscode-typescript-next"
  ]
}

// .vscode/settings.json
{
  "editor.formatOnSave": true,
  "editor.defaultFormatter": "esbenp.prettier-vscode",
  "eslint.validate": [
    "javascript",
    "javascriptreact",
    "typescript",
    "typescriptreact"
  ],
  "typescript.tsdk": "node_modules/typescript/lib"
}

# .env (optional - not recommended for external contributors)
NEW_EXPENSIFY_URL=https://dev.new.expensify.com
SECURE_EXPENSIFY_URL=https://www.expensify.com/api
EXPENSIFY_URL=https://www.expensify.com
USE_WEB_PROXY=true  # External contributors should set this

# Enable Redux DevTools for Onyx debugging
USE_REDUX_DEVTOOLS=true

# Enable Why Did You Render for performance debugging
USE_WDYR=true

# Capture performance metrics
CAPTURE_METRICS=true
ONYX_METRICS=true

# Terminal 1: Metro bundler (for React Native)
npm start

# Terminal 2: Run platform
npm run web     # or ios/android

# Format code (REQUIRED before commit)
npm run prettier

# Lint
npm run lint

# Type check (fast, development)
npm run typecheck-tsgo

# Type check (production gate)
npm run typecheck

# Run all checks
npm run prettier && npm run lint && npm run typecheck

# Run all tests
npm test

# Run specific test file
npm test -- MyComponent.test.tsx

# Run tests in watch mode
npm test -- --watch

# Clean everything
npm run clean

# Reinstall dependencies
npm install

# iOS: Reinstall pods
cd ios && pod install && cd ..

# Android: Clean gradle
cd android && ./gradlew clean && cd ..

# Clear React Native cache
npm start -- --reset-cache

# Nuclear option: Delete everything and start over
rm -rf node_modules ios/Pods ios/Podfile.lock
npm install
cd ios && pod install && cd ..

# Install globally
npm install -g react-devtools

# Run
react-devtools

# In app, shake device (or Cmd+D) > "Toggle Inspector"

# Run performance tests
npm run test:perf

# Compare with baseline
npm run test:perf -- --compare

# Kill process on port 8081
lsof -ti:8081 | xargs kill -9

# Restart metro
npm start

# Check current version
node --version

# Use correct version
nvm use

# Install if missing
nvm install

cd ios
rm -rf Pods Podfile.lock
pod install --repo-update
cd ..

cd android
./gradlew clean
cd ..
rm -rf android/.gradle
npm run android