How to have different return values for multiple calls on a Jasmine spy How to have different return values for multiple calls on a Jasmine spy javascript javascript

How to have different return values for multiple calls on a Jasmine spy


You can use spy.and.returnValues (as Jasmine 2.4).

for example

describe("A spy, when configured to fake a series of return values", function() {  beforeEach(function() {    spyOn(util, "foo").and.returnValues(true, false);  });  it("when called multiple times returns the requested values in order", function() {    expect(util.foo()).toBeTruthy();    expect(util.foo()).toBeFalsy();    expect(util.foo()).toBeUndefined();  });});

There is some thing you must be careful about, there is another function will similar spell returnValue without s, if you use that, jasmine will not warn you.


For older versions of Jasmine, you can use spy.andCallFake for Jasmine 1.3 or spy.and.callFake for Jasmine 2.0, and you'll have to keep track of the 'called' state, either through a simple closure, or object property, etc.

var alreadyCalled = false;spyOn(util, "foo").andCallFake(function() {    if (alreadyCalled) return false;    alreadyCalled = true;    return true;});