Angular unit test Calling a method from the constructor of a class

Angular unit test Calling a method from the constructor of a class

Jasmine spyon is a double function to test methods and objects of a class in Javascript and typescript.

It allows you to call methods or functions and returns the result.

Syntax

spyOn(object, "function").withArgs(arguments).and.returnValue(value);

Angular unit test Calling a method from the constructor of a class

Here is an example of calling a method from a construction

myclass = function () {
  this.mymethod();
};

myclass.prototype.mymethod = function () {
  console.log("mymethod");
};

describe("The myclass constructor", function () {
  it("should call its prototype's mymethod", function () {
    spyOn(myclass.prototype, "mymethod"); //.andCallThrough();
    var myc = new myclass();
    expect(myclass.prototype.mymethod).toHaveBeenCalled();
  });
});