errors.js

class AppError extends Error {
  constructor (message) {
    super(message);

    this.name = '';
    this.code = 0;
  }
}

class BadRequestError extends AppError {
  constructor (message) {
    super(message || 'Bad Request');

    this.name = 'BadRequestError';
    this.code = 400;
  }
}

class NotFoundError extends AppError {
  constructor (message) {
    super(message || 'Not Found');

    this.name = 'NotFoundError';
    this.code = 404;
  }
}

class MethodNotAllowedError extends AppError {
  constructor (message) {
    super(message || 'Method Not Allowed');

    this.name = 'MethodNotAllowedError';
    this.code = 405;
  }
}

class TeapotError extends AppError {
  constructor (message) {
    super(message || 'I\'m a teapot');

    this.name = 'TeapotError';
    this.code = 418;
  }
}

class UnprocessableEntityError extends AppError {
  constructor (message) {
    super(message || 'Unprocessable Entity');

    this.name = 'UnprocessableEntityError';
    this.code = 422;
  }
}

class InternalServerError extends AppError {
  constructor (message) {
    super(message || 'Internal Server Error');

    this.name = 'InternalServerError';
    this.code = 500;
  }
}

module.exports = {
  AppError,
  BadRequestError,
  NotFoundError,
  MethodNotAllowedError,
  TeapotError,
  UnprocessableEntityError,
  InternalServerError,
};