How to spyOn a value property (rather than a method) with Jasmine

Question

Jasmine\'s spyOn is good to change a method\'s behavior, but is there any way to change a value property (rather than a method) for an object? the code could be

Answer 1

If you are using ES6 (Babel) or TypeScript you can stub out the property using get and set accessors

export class SomeClassStub {
  getValueA = jasmine.createSpy('getValueA');
  setValueA = jasmine.createSpy('setValueA');
  get valueA() { return this.getValueA(); }
  set valueA(value) { this.setValueA(value); }
}

Then in your test you can check that the property is set with:

stub.valueA = 'foo';

expect(stub.setValueA).toHaveBeenCalledWith('foo');