Extending Error in Javascript with ES6 syntax & Babel

Question

I am trying to extend Error with ES6 and Babel. It isn\'t working out.

class MyError extends Error {
  constructor(m) {
    super(m);
  }
}

var error = new          


        

Answer 1

With the latest changes in babel 6, I find transform-builtin-extend no longer working. I ended up using this mixed approach:

export default class MyError {
    constructor (message) {
        this.name = this.constructor.name;
        this.message = message;
        this.stack = (new Error(message)).stack;
    }
}

MyError.prototype = Object.create(Error.prototype);
MyError.prototype.constructor = MyError;

and

import MyError from './MyError';

export default class MyChildError extends MyError {
    constructor (message) {
        super(message);
    }
}

As a result all these tests pass:

const sut = new MyError('error message');
expect(sut.message).toBe('error message');
expect(sut).toBeInstanceOf(Error);
expect(sut).toBeInstanceOf(MyError);
expect(sut.name).toBe('MyError');
expect(typeof sut.stack).toBe('string');

const sut = new MyChildError('error message');
expect(sut.message).toBe('error message');
expect(sut).toBeInstanceOf(Error);
expect(sut).toBeInstanceOf(MyError);
expect(sut).toBeInstanceOf(MyChildError);
expect(sut.name).toBe('MyChildError');
expect(typeof sut.stack).toBe('string');