In the following unit test code:
TestModel = Backbone.Model.extend({
defaults: {
'selection': null
},
initialize: function() {
this.on('change:selection', this.doSomething);
},
doSomething: function() {
console.log("Something has been done.");
}
});
module("Test", {
setup: function() {
this.testModel = new TestModel();
}
});
test("intra-model event bindings", function() {
this.spy(this.testModel, 'doSomething');
ok(!this.testModel.doSomething.called);
this.testModel.doSomething();
ok(this.testModel.doSomething.calledOnce);
this.testModel.set('selection','something new');
ok(this.testModel.doSomething.calledTwice); //this test should past, but fails. Console shows two "Something has been done" logs.
});
The third ok fails, even though the function was effectively called from the backbone event binding, as demo'd by the console.
This is very frustrating and has shaken my confidence on whether sinon.js is suitable for testing my backbone app. Am I doing something wrong, or is this a problem with how sinon detects whether something has been called? Is there a workaround?
EDIT: Here's a solution to my specific example, based on the monkey patch method of the accepted answer. While its a few lines of extra setup code in the test itself, (I don't need the module function any more) it gets the job done. Thanks, mu is too short
test("intra-model event bindings", function() {
var that = this;
var init = TestModel.prototype.initialize;
TestModel.prototype.initialize = function() {
that.spy(this, 'doSomething');
init.call(this);
};
this.testModel = new TestModel();
. . . // tests pass!
});