Spy Strategies

When we set up a spy in Jasmine, it can respond to method calls in a number of ways. The default behavior is to use the stub method, which will do nothing. We also have a few other options available:

• We can use callFake to provide a callback that will be fired instead of the real method.

• We can use callThrough to pass the method call on to the original object that we are spying on.

• We can specify a value to be returned using the returnValue or returnValues method.

• We can use the throwError to throw an error if the method is called. We could use this if we want to make certain that a specific method on the spy is never called.