Mastering JavaScript

Chapter 6
"port":"8000",
"client-encoding":"UTF-8"
});
});
it("the spy was called", function() {
expect(configurator.submitPOSTRequest).toHaveBeenCalled();
});
it("the arguments of the spy's call are tracked", function() {
expect(configurator.submitPOSTRequest).toHaveBeenCalledWith({"port
":"8000","client-encoding":"UTF-8"});
});
});
In this example, while we are writing this test case, we either don't have the real
implementation of the configurator.submitPOSTRequest() dependency or
someone is fixing this particular dependency. In any case, we don't have it available.
For our test to work, we need to mock it. Jasmine spies allow us to replace a function
with its mock and track its execution.
In this case, we need to ensure that we called the dependency. When the actual
dependency is ready, we will revisit this test case to make sure that it fits the
specifications, but at this time, all that we need to ensure is that the dependency is
called. The Jasmine tohaveBeenCalled() function lets us track the execution of a
function, which may be a mock. We can use toHaveBeenCalledWith() that allows
us to determine if the stub function was called with the correct parameters. There
are several other interesting scenarios that you can create using Jasmine spies. The
scope of this chapter won't permit us to cover them all, but I would encourage you to
discover these areas on your own.
You can refer to the user manual for Jasmine for more information
on Jasmine spies at http://jasmine.github.io/2.0/
introduction.html.
Mocha, Chai, and Sinon
Though Jasmine is the most prominent JavaScript testing framework,
Mocha and Chai are gaining prominence in the Node.js environment.
Mocha is the testing framework used to describe and run test cases.
Chai is the assertion library supported by Mocha. Sinon.JS comes in
handy while creating mocks and stubs for your tests. We won't discuss
these frameworks in this book, but experience on Jasmine will be handy
if you want to experiment with these frameworks.
[ 153 ]
www.it-ebooks.info