How to mock object for document element with Jasmine and JavaScript?

To mock object for document element with Jasmine and JavaScript, we use the createSpy method.

For instance, we write

const dummyElement = document.createElement("div");
document.getElementById = jasmine
  .createSpy("HTML Element")
  .and.returnValue(dummyElement);

to call createSpy to create a spy and make it return a value with returnValue.

And we set that as the value of document.getElementById.

Conclusion

To mock object for document element with Jasmine and JavaScript, we use the createSpy method.