Exploring the World of Unit Testing with Jasmine and Sinon Factories

Question

Exploring the World of Unit Testing with Jasmine and Sinon Factories

At my factory, I have implemented a getter and setter function

.factory('myService', function() {
  var car = null;
  return {
    car: car,
    get: function get() {
      return car;
    },
    set: function set(newCar) {
      car = newCar;
    }
  };
});

While writing tests for this functionality, I am facing an issue where the set method does not seem to update the value of car as expected.

myService.set = sinon.spy();
myService.get = sinon.spy()

it('should set car to new car', function () {
  var newCar = ['a','b','c'];
  expect(myService.car).toEqual(null); //pass

  myService.set(newCar);

  dump(myService.car); //null

  expect(myService.set).toHaveBeenCalledWith(newCar);//pass

  expect(myService.get).toHaveReturned(newCar);//fail

});

Can anyone provide some insights on what mistake I might be making in this scenario?

javascript angularjs jasmine sinon

Answer 1

Answer №1

There are multiple issues at play here.

Firstly, the .car property is set to null initially and never gets updated, leading to a perpetual state of null:

var car = null;
return {
  car: car,
  get: function get() {
    return car;
  },
  set: function set(newCar) {
    car = newCar;
  }
};

An alternative approach could be initializing car as null within the object itself:

return {
  car: null,
  get: function get() {
    return this.car;
  },
  set: function set(newCar) {
    this.car = newCar;
  }
};

However, using this in this context may lead to potential complications down the line. Furthermore, it's puzzling why you're exposing car when you already have a getter for it.

Additionally, by replacing the original get and set functions with Sinon spies like so:

myService.set = sinon.spy();
myService.get = sinon.spy();

You lose access to the original get and set functionalities. Instead, consider wrapping the functions with Sinon spies without losing their original behaviors:

sinon.spy(myService, 'set');

This way, Sinon can spy on the functions while preserving their functionality. For more information, refer to the Sinon documentation.

Answer 2

There are multiple issues at play here.

Firstly, the .car property is set to null initially and never gets updated, leading to a perpetual state of null:

var car = null;
return {
  car: car,
  get: function get() {
    return car;
  },
  set: function set(newCar) {
    car = newCar;
  }
};

An alternative approach could be initializing car as null within the object itself:

return {
  car: null,
  get: function get() {
    return this.car;
  },
  set: function set(newCar) {
    this.car = newCar;
  }
};

However, using this in this context may lead to potential complications down the line. Furthermore, it's puzzling why you're exposing car when you already have a getter for it.

Additionally, by replacing the original get and set functions with Sinon spies like so:

myService.set = sinon.spy();
myService.get = sinon.spy();

You lose access to the original get and set functionalities. Instead, consider wrapping the functions with Sinon spies without losing their original behaviors:

sinon.spy(myService, 'set');

This way, Sinon can spy on the functions while preserving their functionality. For more information, refer to the Sinon documentation.

Exploring the World of Unit Testing with Jasmine and Sinon Factories

Answer №1

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