嘲笑测试函数，调用eval

Question

I have a Vue TS project created with vue-cli 3.0.

This is the function I will test:

 public hopJavascript(url: string) { eval(url); } 

And this is my test function using Jest framework:

 test('navigation using javascript', () => { const url = "someurl"; hopJavascript(url); expect(eval).toBeCalled(); }); 

Now i get this message, test failed console logging which is telling me that I need a mocked version of eval.

How can i mock eval ?

Answer 1

Update

It seems you can't always override eval based on your JS environment (browser or node). See the answer to "How override eval function in javascript?" for more information

Original answer

I think you can redefine eval in your test file:

global.eval = jest.fn()

Answer 2

You need to track your function with spyOn().

This solution should work for you.

import MyClass from '../MyClass';

test('navigation using javascript', () => {
    const url = "someurl";
    const spy = jest.spyOn(MyClass, 'eval');

    MyClass.hopJavascript(url);

    expect(spy).toHaveBeenCalled();
});