Doesn't work properly with ember-cli-chai

[al3xnag]

Problem

Chai assertion expect(3).to.equal(3); replaces with expect(3).to.equal('expect(3).to.equal(3) at my-app/tests/unit/mixins/foo-test.js:x:x');

I don't pretend to have nice errors for chai assertions, at least ember-qunit-nice-errors shouldn't touch them.

Details

$ npm ls ember-cli-chai ember-qunit-nice-errors
├── ember-cli-chai@0.4.2 
└── ember-qunit-nice-errors@1.1.2 

// config/environment.js
'ember-qunit-nice-errors': {
  showFileInfo: true,
  completeExistingMessages: true
},

// /tests/unit/mixins/foo-test.js
import { module, test } from 'qunit';
import { withChai } from 'ember-cli-chai/qunit';

module('Unit | Mixin | foo');

test('it works', withChai(function(expect, assert) {
  expect(3).to.equal(3);
}));

$ ember test -> 

Failed.
expected 3 to equal 'expect(3).to.equal(3) at my-app/tests/unit/mixins/foo-test.js:x:x'@ 5 ms
Expected: "expect(3).to.equal(3) at my-app/tests/unit/mixins/foo-test.js:x:x"
Result: 3