It is often more obvious to pass the spy as a property of the object spied upon instead of from a referencing variable.
The following are considered warnings:
var someSpy = spyOn(someObj, 'someMethod');
// Handle someSpy, for example
// expect(someSpy).toHaveBeenCalled();
The following are not warnings:
spyOn(someObj, 'someMethod');
// Handle someObj.someMethod, for example
// expect(someObj.someMethod).toHaveBeenCalled();