javascriptjqueryjasminejasmine-jquery

Do you need spies to test if a function has been called in Jasmine?


Am learning Jasmine, wondering if the following test would be valid? And if not, can someone explain why? I've been reading a number of tutorials and can't find a good explanation that has helped me understand why I can't seem to write a test like the one below correctly.

// spec
describe("when cart is clicked", function() {
    it("should call the populateNotes function", function() {
        $("#show-cart").click()
        expect(populateNotes()).toHaveBeenCalled();
    })
})

// code
$("#show-cart").click(function() {
    populateNotes();
})

Solution

  • You need to do two things, first you need to spy on the function before the click. Normally you would spy on a function like this that is a member of an object. Where is populateNotes defined? You need a reference to it somehow.

    // This might work, if the function is defined globally. 
    spyOn(window, 'populateNotes');
    
    // Then do your action that should result in that func being called
    $("#show-cart").click();
    
    // Then your expectation. The expectation should be on the function
    // itself, not on the result. So no parens.
    expect(window.populateNotes).toHaveBeenCalled();