M2JSAI-Ready Docs + Smart Dead Code Detection

export class AuthService {
private readonly jwtSecret: string;
private readonly tokenExpiry: number;
private readonly userRepository: UserRepository;
private readonly loggerService: LoggerService;

constructor(
userRepo: UserRepository,
logger: LoggerService,
config: AuthConfig
) {
this.userRepository = userRepo;
this.loggerService = logger;
this.jwtSecret = config.jwtSecret;
this.tokenExpiry = config.tokenExpiry || 3600;
}

/**
* Authenticate user with email and password
* Business rule: Rate limiting - max 5 attempts per hour
* Security: Passwords must be validated with bcrypt
*/
async login(email: string, password: string): Promise<AuthResult> {
try {
// Validate input parameters
if (!email || !password) {
this.loggerService.warn('Login attempt with missing credentials');
throw new AuthenticationError('Email and password are required');
}

// Check rate limiting
const attempts = await this.getRateLimitAttempts(email);
if (attempts >= 5) {
this.loggerService.warn(`Rate limit exceeded for email: ${email}`);
throw new RateLimitError('Too many login attempts. Try again later.');
}

// Fetch user from database
const user = await this.userRepository.findByEmail(email);
if (!user || !user.isActive) {
this.loggerService.warn(`Login attempt for inactive user: ${email}`);
throw new AuthenticationError('Invalid credentials');
}

// Validate password
const isPasswordValid = await bcrypt.compare(password, user.passwordHash);
if (!isPasswordValid) {
await this.incrementRateLimitAttempts(email);
this.loggerService.warn(`Invalid password for user: ${email}`);
throw new AuthenticationError('Invalid credentials');
}

// Generate JWT token
const payload = {
userId: user.id,
email: user.email,
role: user.role,
iat: Math.floor(Date.now() / 1000),
exp: Math.floor(Date.now() / 1000) + this.tokenExpiry
};

const token = jwt.sign(payload, this.jwtSecret);

// Reset rate limiting on successful login
await this.resetRateLimitAttempts(email);

// Log successful authentication
this.loggerService.info(`Successful login for user: ${email}`);

// Return authentication result
return {
success: true,
token,
user: {
id: user.id,
email: user.email,
name: user.name,
role: user.role
},
expiresAt: new Date(Date.now() + this.tokenExpiry * 1000)
};

} catch (error) {
if (error instanceof AuthenticationError || error instanceof RateLimitError) {
throw error;
}

this.loggerService.error('Unexpected error during authentication:', error);
throw new AuthenticationError('Authentication failed');
}
}

// ... 150+ more lines of helper methods
}

const result = await authService.login('user@example.com', 'password123');
if (result.success) {
console.log('Logged in:', result.user.email);
}