Extra Features of the Expect.js

Install

npm install expect.js-extra

Usage

// Instead of require('expect.js');
var expect = require('expect.js-extra');

containEql: works like contain, but uses the deep equality

expect([{ a: 1, b: 2 }, { a: 3, b: 4 }]).to.containEql({ a: 1, b: 2 });

be.a('promise') asserts object to be a promise (have the then method)

var obj = { then: function() {} };
expect(obj).to.be.a('promise');

fulfill asserts a promise to fulfill. It returns a promise, so don't forget to use return.

var Q = require('q');

it('is fulfilled', function() {
  return expect(Q()).to.fulfill();
});

it('is not fulfilled', function() {
  return expect(Q.reject()).to.not.fulfill();
});

Check the resolved value.

var Q = require('q');

it('is fulfilled', function() {
  var promise = Q('ok');

  return expect(promise).to
    .fulfill()
    .then(function(result) {
      expect(result).to.be('ok');
    });
});

reject([expected reason]) asserts a promise to reject. It returns a promise, so don't forget to use return.

var Q = require('q');

it('is rejected', function() {
  return expect(Q.reject()).to.reject();
});

it('is rejected with the proper reason', function() {
  var promise = Q.reject('something wrong');
  return expect(promise).to.reject('something wrong');
);

// or

it('is rejected with the proper reason', function() {
  var promise = Q.reject('something wrong');
  return expect(promise).to.reject(/wrong/);
);

it('is not rejected', function() {
  return expect(Q()).to.not.reject();
});

Another way to check the rejection reason.

var Q = require('q');

it('is rejected', function() {
  var promise = Q.reject('something wrong happened');

  return expect(promise).to
    .reject()
    .then(function(reason) {
      expect(reason).to.be('something wrong happened');
    });
});