CODEWITHSUNDEEP
javascriptjasmine
Zoltan Toth
Zoltan Toth

Reputation: 47657

Jasmine: How to properly spy on a function call?

I'm trying to test a function call in the next scenario:

JS:

var Demo = function(option) {
  if (option) func();

  function func() {
    console.log('called')
  }

  return {
    'func': func
  }
}

Jasmine: 

beforeEach(function() {
  var demo = new Demo(true);
  spyOn(demo, 'func');

  this.demo = demo;
});

it("should call func()", function() {
  expect(this.demo.func).toHaveBeenCalled();
});

Despite it logs 'called' in the console it fails the spec with:

Expected spy func to have been called.

From the code flow I suppose it happens because the spying begins after the function was called. So my question - what is the proper way to capture the function call in the test?

JSFiddle

Upvotes: 0

Views: 3449

Answers (1)

ThrowsException
ThrowsException

Reputation: 2636

This may be a better way to do this. Add func as part of the Demo prototype. then you can hook up the spy to the prototype.

var Demo = function(option) {
  if (option) this.func();
}

Demo.prototype.func = function(){
    console.log("called")
}

beforeEach(function() {
    spyOn(Demo.prototype, 'func')
  var demo = new Demo(true);
  this.demo = demo;
});

it("should call func()", function() {
  expect(this.demo.func).toHaveBeenCalled();
});

http://jsfiddle.net/kfu7fok1/6/

Upvotes: 1

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