pact-coding-standards

PACT Coding Standards

Clean code principles for the Code phase of PACT. This skill provides essential coding guidelines and links to detailed patterns for implementation.

Core Principles

1. Single Responsibility Principle

Each function, class, or module should have exactly one reason to change.

// BAD: Multiple responsibilities
class UserManager {
  createUser(data) { }
  validateEmail(email) { }
  sendWelcomeEmail(user) { }
  generateReport() { }
  updateUserPreferences(userId, prefs) { }
}

// GOOD: Single responsibility each
class UserService {
  createUser(data) { }
  updateUser(userId, data) { }
}

class EmailValidator {
  validate(email) { }
}

class NotificationService {
  sendWelcomeEmail(user) { }
}

class UserReportGenerator {
  generate(criteria) { }
}

2. DRY (Don't Repeat Yourself)

Extract duplicated logic into reusable functions.

// BAD: Duplicated validation logic
function createUser(data) {
  if (!data.email || !data.email.includes('@')) {
    throw new Error('Invalid email');
  }
  // ...
}

function updateUser(id, data) {
  if (data.email && !data.email.includes('@')) {
    throw new Error('Invalid email');
  }
  // ...
}

// GOOD: Extracted validation
function validateEmail(email) {
  if (!email || !email.includes('@')) {
    throw new ValidationError('Invalid email format');
  }
}

function createUser(data) {
  validateEmail(data.email);
  // ...
}

function updateUser(id, data) {
  if (data.email) {
    validateEmail(data.email);
  }
  // ...
}

3. KISS (Keep It Simple, Stupid)

Choose the simplest solution that works.

// BAD: Over-engineered
class ConfigurationFactoryBuilderManager {
  static getInstance() {
    return new ConfigurationFactoryBuilder()
      .withDefaults()
      .withEnvironment()
      .build()
      .getConfiguration();
  }
}

// GOOD: Simple and direct
const config = {
  port: process.env.PORT || 3000,
  dbUrl: process.env.DATABASE_URL,
  debug: process.env.NODE_ENV !== 'production'
};