BuildErrors

builderrors.js

var inherits = require('inherits');

var Point = function(){};
Point.Errors = {};

var defineErrors = function(base, specs){
  specs.forEach(function(spec){
    var e = function(message){
      this.message = message || spec.message;
    };
    e.name = spec.name;
    inherits(e, spec.inherits);
    Object.defineProperty(base, spec.name,  {
      configurable: false,
      value: e
    });
  });
};

var errors = [
  {
    name: 'InvalidY',
    message: 'Invalid Y point for secp256k1 curve.',
    inherits: TypeError
  }
];

defineErrors(Point.Errors, errors);

var y = '847204eoneotffff';

try {
  throw new Point.Errors.InvalidY('Invalid y: '+ y + ' for the secp256k1 curve.');
} catch(e){
  if (e instanceof Point.Errors.InvalidY){
    console.log(e);
  }
}