How to write unit test for AngularJS model - unit-testing

Question

I've got a basic model that I am trying to write a simple unit test suite for, and I'm clearly missing something...
The code for the model looks like this:
angular.module('AboutModel', [])
.factory(
'AboutModel',
[
function () {
var paragraphs = [];
var AboutModel = {
setParagraphs: function (newParagraphs) {
paragraphs = newParagraphs;
},
getParagraphs: function () {
return paragraphs;
}
};
return AboutModel;
}
]
);
The requirement is simple: provide a getter and a setter method for the private array called paragraphs.
And here is as far as I have got with the test suite code:
describe('Testing AboutModel:', function () {
describe('paragraphs setter', function () {
beforeEach(module('AboutModel'));
it('sets correct value', inject(function (model) {
// STUCK HERE
// don't know how to access the model, or the setParagraphs() method
}));
});
describe('paragraphs getter', function () {
// not implemented yet
});
});
I've been doing quite a bit of google research on the web, but so far no joy.
The solution must be simple; please help!
And it might even be the case that there's a better way of implementing the Model... open to suggestions to make it better.
For anyone interested, the full source code is here:
https://github.com/mcalthrop/profiles/tree/imp/angular
thanks in advance
Matt

Answer 1

You need to run a beforeEach in your test to inject the model instance and then assign it to a variable which you can then re-use through out your tests.
var AboutModel;
beforeEach(inject(function (_AboutModel_) {
AboutModel = _AboutModel_;
}));
You can then access your getter like so:
AboutModel.getParagraphs();
I have tweaked your original model slightly as I feel it reads a little better (my preference):
'use strict';
angular.module('anExampleApp')
.factory('AboutModel', function () {
var _paragraphs;
// Public API here
return {
setParagraphs: function (newParagraphs) {
_paragraphs = newParagraphs;
},
getParagraphs: function () {
return _paragraphs;
}
};
});
And then for testing I would use a combination of the standard Jasmine tests and spies:
'use strict';
describe('Service: AboutModel', function () {
beforeEach(module('anExampleApp'));
var AboutModel, paragraphs = ['foo', 'bar'];
beforeEach(inject(function (_AboutModel_) {
AboutModel = _AboutModel_;
}));
it('should set new paragraphs array', function () {
AboutModel.setParagraphs([]);
expect(AboutModel.getParagraphs()).toBeDefined();
});
it('should call setter for paragraphs', function () {
spyOn(AboutModel, 'setParagraphs');
AboutModel.setParagraphs(paragraphs);
expect(AboutModel.setParagraphs).toHaveBeenCalledWith(paragraphs);
});
it('should get 2 new paragraphs', function () {
AboutModel.setParagraphs(['foo', 'bar']);
expect(AboutModel.getParagraphs().length).toEqual(2);
});
});