Streaming Data with Ajax and Comet - Test-Driven JavaScript Development - page 324

13.4.3.1 Adding ajax.cometClient.dispatch
The first test for dispatching data is simply asserting that a method exists,
as Listing 13.45 shows.
Listing 13.45 Expecting dispatch to exist
"test should have dispatch method": function () {
var client = Object.create(ajax.cometClient);
assertFunction(client.dispatch);
}
This test fails, so Listing 13.46 adds it in.
Listing 13.46 Adding the dispatch method
function dispatch() {
}
ajax.cometClient = {
dispatch: dispatch
};
13.4.3.2 Delegating Data
Next, we're going to feed dispatch an object, and make sure it pushes data out
to observers. However, we haven't written observe yet, which means that if we
now write a test that requires both methods to work correctly, we're in trouble
if either fail. Failing unit tests should give a clear indication of where a problem
occurred, and using two methods to verify each other's behavior is not a good idea
when none of them exist. Instead, we will leverage the fact that we're going to use
observable to implement both of these. Listing 13.47 expects dispatch to call
notify on the observable observers object.
Listing 13.47 Expecting dispatch to notify
"test dispatch should notify observers": function () {
var client = Object.create(ajax.cometClient);
client.observers = { notify: stubFn() };
client.dispatch({ someEvent: [{ id: 1234 }] });
var args = client.observers.notify.args;