A promise implementation

covenant.js

const noop = () => void 0;

function Covenant(fn) {
    this.resolver = fn;
    this.thenCallback = noop;
    this.catchCallback = noop;

    this.resolver((...args) => {
        this.thenCallback(...args);
    }, () => {
        this.thenCallback = noop;
        this.catchCallback('error');
    });

}

Covenant.prototype.then = function(fn) {
    this.thenCallback = fn;
    return this;
};

Covenant.prototype.catch = function(fn) {
    this.catchCallback = fn;
    return this;
};


let c = new Covenant((resolve, reject) => {
    // setTimeout(() => reject(), 500);
    setTimeout(() => resolve('woot'), 1000);
});


c.then((something) => {
    console.log(`${something}, done!`);
}).catch(() => {
    console.log('oh shat');
});