Mocking getting out of control in chapter 14

ch_14_extract.asciidoc

Taking another look at our Mozilla Persona spike, we need something like this:

var loggedInUser = '{{ user.email }}' || null;
var csrf_token = '{{ csrf_token }}';
console.log(loggedInUser);

navigator.id.watch({
  loggedInUser: loggedInUser, //(1)
  onlogin: function(assertion) {
    $.post('/accounts/login', {assertion: assertion, csrfmiddlewaretoken: csrf_token}) //(2)
    .done(function() { window.location.reload(); })
    .fail(function() { navigator.id.logout();});
  },
  onlogout: function() {
    $.post('/accounts/logout')
    .always(function() { window.location.reload(); });
  }
});

Decoding that, the watch function needs to know a couple of things from the global scope:

1. the current user’s email, to be passed in as the loggedInUser parameter to watch

2. the current CSRF token, to pass in the Ajax POST request to the login view

We’ve also got two hard-coded URLs in there, which it would be better to get from Django, something like this:

var urls = {
    login: "{% url 'login' %}",
    logout: "{% url 'logout' %}",
};

So that would be a third parameter to pass in from the global scope. We’ve already got an initialize function, so let’s imagine using it like this:

Superlists.Accounts.initialize(navigator, loggedInUser, urls);

So how would we re-write all this, in a TDD way, with unit tests first? What will the unit tests be like? Mock central!

test("initialize calls navigator.id.watch", function () {
    var loggedInUser = 'current user';
    var urls = { login: 'login url', logout: 'logout url'};
    var watchFunctionCalled = false;

    var mockWatchFunction = function (params) {
        equal(params.loggedInUser, loggedInUser, 'wrong user');
        equal(params.onlogin, Superlists.Accounts.onLogin, 'wrong onlogin function');
        equal(params.onlogout, Superlists.Accounts.onLogout, 'wrong onlogout function');
    };
    var mockNavigator = {
        id: {
            watch: mockWatchFunction
        }
    };

    Superlists.Accounts.initialize(mockNavigator, loggedInUser, urls);

    equal(watchFunctionCalled, true, 'never called watch function');

});