使用qunit测试javascript函数

Question

I declare a ViewModel within a javascript file as per below.

(function(root) {
    var ko = root.ko;

    var vm = {
        modelType: ko.observable(),
        message : ko.observable(),
        toolbarIsVisible : ko.observable(true),
        isDataDirectoryManager : ko.observable(true),
        listItems : ko.observableArray(),

     ko.applyBindings(vm);

    };
}(window));

In my unit test js file I reference qunit.js and the js file with the vm. How do I construct a test to inspect the value of (say) toolbarIsVisible. I can't seem to write the correct syntax to reference the vm variable in my test.

Thanks Martin

Answer 1

Its a closure, so only way to get it from a test is to mock ko.applyBindings and retrive the vm value from there.

But I really think you should make your VM's public like this

(function(ko, MyApp) {
    MyApp.ViewModel = {
        modelType: ko.observable(),
        message : ko.observable(),
        toolbarIsVisible : ko.observable(true),
        isDataDirectoryManager : ko.observable(true),
        listItems : ko.observableArray()
    };
    ko.applyBindings(ViewModel);

}(window.ko, window.MyApp = window.MyApp || {}));

edit: Another tip is not to use object literals but prototype objects like

MyApp.ViewModel = function() {
    this.modelType = ko.observable();
};

MyApp.ViewModel.prototype = {
    foo: function() {
    }        
};

edit: Qunit example

test("When model is valid", function() {
   var model = MyApp.ViewModel();
   model.value("Valid value");
   equal(model.canSave(), true, "You should be able to save");
});