I am trying to test angular service which does some manipulations to DOM via $document
service with jasmine.
Let's say it simply appends some directive to the <body>
element.
Such service could look like
(function(module) {
module.service('myService', [
'$document',
function($document) {
this.doTheJob = function() {
$document.find('body').append('<my-directive></my directive>');
};
}
]);
})(angular.module('my-app'));
And I want to test it like this
describe('Sample test' function() {
var myService;
var mockDoc;
beforeEach(function() {
module('my-app');
// Initialize mock somehow. Below won't work indeed, it just shows the intent
mockDoc = angular.element('<html><head></head><body></body></html>');
module(function($provide) {
$provide.value('$document', mockDoc);
});
});
beforeEach(inject(function(_myService_) {
myService = _myService_;
}));
it('should append my-directive to body element', function() {
myService.doTheJob();
// Check mock's body to contain target directive
expect(mockDoc.find('body').html()).toContain('<my-directive></my-directive>');
});
});
So the question is what would be the best way to create such mock?
Testing with real document
will give us much trouble cleaning up after each test and does not look like a way to go with.
I've also tried to create a new real document instance before each test, yet ended up with different failures.
Creating an object like below and checking whatever
variable works but looks very ugly
var whatever = [];
var fakeDoc = {
find: function(tag) {
if (tag == 'body') {
return function() {
var self = this;
this.append = function(content) {
whatever.add(content);
return self;
};
};
}
}
}
I feel that I'm missing something important here and doing something very wrong.
Any help is much appreciated.
You don't need to mock the $document
service in such a case. It's easier just to use its actual implementation:
describe('Sample test', function() {
var myService;
var $document;
beforeEach(function() {
module('plunker');
});
beforeEach(inject(function(_myService_, _$document_) {
myService = _myService_;
$document = _$document_;
}));
it('should append my-directive to body element', function() {
myService.doTheJob();
expect($document.find('body').html()).toContain('<my-directive></my-directive>');
});
});
Plunker here.
If you really need to mock it out, then I guess you'll have to do it the way you did:
$documentMock = { ... }
But that can break other things that rely on the $document
service itself (such a directive that uses createElement
, for instance).
UPDATE
If you need to restore the document back to a consistent state after each test, you can do something along these lines:
afterEach(function() {
$document.find('body').html(''); // or $document.find('body').empty()
// if jQuery is available
});
Plunker here (I had to use another container otherwise Jasmine results wouldn't be rendered).
As @AlexanderNyrkov pointed out in the comments, both Jasmine and Karma have their own stuff inside the body
tag, and wiping them out by emptying the document body doesn't seem like a good idea.
UPDATE 2
I've managed to partially mock the $document
service so you can use the actual page document and restore everything to a valid state:
beforeEach(function() {
module('plunker');
$document = angular.element(document); // This is exactly what Angular does
$document.find('body').append('<content></content>');
var originalFind = $document.find;
$document.find = function(selector) {
if (selector === 'body') {
return originalFind.call($document, 'body').find('content');
} else {
return originalFind.call($document, selector);
}
}
module(function($provide) {
$provide.value('$document', $document);
});
});
afterEach(function() {
$document.find('body').html('');
});
Plunker here.
The idea is to replace the body
tag with a new one that your SUT can freely manipulate and your test can safely clear at the end of every spec.