justmoon

'use strict';

module.exports = function CustomError(message, extra) {
  Error.captureStackTrace(this, this.constructor);
  this.name = this.constructor.name;
  this.message = message;
  this.extra = extra;
};

require('util').inherits(module.exports, Error);

speric

Chapter 1 - Object Oriented Design

The purpose of design is to allow you to do design later, and it's primary goal is to reduce the cost of change.

SOLID Design:

• Single Responsibility Principle: a class should have only a single responsibility
• Open-Closed Principle: Software entities should be open for extension, but closed for modification (inherit instead of modifying existing classes).
• Liskov Substitution: Objects in a program should be replaceable with instances of their subtypes without altering the correctness of that program.
• Interface Segregation: Many client-specific interfaces are better than one general-purpose interface.