How do we clear spy programmatically in Jasmine?

Question

How do we clear the spy in a jasmine test suite programmatically? Thanks.

beforeEach(function() {
  spyOn($, \"ajax\").andCallFake(function(params){
  })
})
         


        

Answer 1

In Jasmine 2, the spy state is held in a SpyStrategy instance. You can get hold of this instance calling $.ajax.and. See the Jasmine source code on GitHub.

So, to set a different fake method, do this:

$.ajax.and.callFake(function() { ... });

To reset to the original method, do this:

$.ajax.and.callThrough();

Answer 2

I think that's what .reset() is for:

spyOn($, 'ajax');

$.post('http://someUrl', someData);

expect($.ajax).toHaveBeenCalled();

$.ajax.calls.reset()

expect($.ajax).not.toHaveBeenCalled();

Answer 3

From jasmine 2.5, you can use this global setting to update a spy within your test cases:

jasmine.getEnv().allowRespy(true);

Answer 4

Or you can do it

describe('test', function() {
    var a, c;
    c = 'spy1';
    a = {
      b: function(){}
    };

    beforeEach(function() {
        spyOn(a, 'b').and.callFake(function () {
             return c;
        });
    })

    it('should return spy1', function() {
        expect(a.b()).toEqual('spy1');
    })

    it('should return spy2', function() {
        c = 'spy2';
        expect(a.b()).toEqual('spy2');
    })

})

In this case you use the same Spy but just change the var that it will return..

Answer 5

I'm not sure if its a good idea but you can simply set the isSpy flag on the function to false:

describe('test', function() {
    var a = {b: function() {
    }};
    beforeEach(function() {
        spyOn(a, 'b').andCallFake(function(params) {
            return 'spy1';
        })
    })
    it('should return spy1', function() {
        expect(a.b()).toEqual('spy1');
    })

    it('should return spy2', function() {
        a.b.isSpy = false;
        spyOn(a, 'b').andCallFake(function(params) {
            return 'spy2';
        })
        expect(a.b()).toEqual('spy2');
    })

})

But maybe its a better idea to create a new suite for this case where you need an other behavior from your spy.

Answer 6

I'm posting this answer to address the comment in OP @Tri-Vuong's code - which was my main reason for my visiting this page:

I want to override the spy ... here and do it a little differently

None of the answers so far address this point, so I'll post what I've learned and summarize the other answers as well.

@Alissa called it correctly when she explained why it is a bad idea to set isSpy to false - effectively spying on a spy resulting in the auto-teardown behavior of Jasmine no longer functioning as intended. Her solution (placed within the OP context and updated for Jasmine 2+) was as follows:

beforeEach(() => {
  var spyObj = spyOn(obj,'methodName').and.callFake(function(params){
  }) // @Alissa's solution part a - store the spy in a variable
})

it("should do the declared spy behavior", () => {
  // Act and assert as desired
})

it("should do what it used to do", () => {
  spyObj.and.callThrough(); // @Alissa's solution part b - restore spy behavior to original function behavior
  // Act and assert as desired
})

it("should do something a little differently", () => {
  spyObj.and.returnValue('NewValue'); // added solution to change spy behavior
  // Act and assert as desired
})

The last it test demonstrates how one could change the behavior of an existing spy to something else besides original behavior: "and-declare" the new behavior on the spyObj previously stored in the variable in the beforeEach(). The first test illustrates my use case for doing this - I wanted a spy to behave a certain way for most of the tests, but then change it for a few tests later.

For earlier versions of Jasmine, change the appropriate calls to .andCallFake(, .andCallThrough(), and .andReturnValue( respectively.