How to mock useref in jest

To mock useRef in Jest, you can use the `jest.spyOn` method along with `React`’s `useRef` function. Here is an example of how you can do it:

// Import the necessary modules
import { useRef } from "react";

// Your component that uses useRef
function MyComponent() {
  const ref = useRef();

  // Code that uses the ref

  return 
This is my component
;
}

// Your test file
describe("MyComponent", () => {
  it("should mock useRef", () => {
    // Spy on the useRef function
    const useRefSpy = jest.spyOn(React, "useRef");

    // Mock the return value of the useRef function
    useRefSpy.mockReturnValue({ current: "mockedRef" });

    // Render your component
    render();

    // Assertions
    expect(useRefSpy).toHaveBeenCalled();
    expect(useRefSpy).toHaveBeenCalledWith();

    // Clean up the spy
    useRefSpy.mockRestore();
  });
});

In this example, we first import the `useRef` function from the `react` module. Then, inside the `MyComponent` function, we use the `useRef` function to create a ref. After that, we have some code that uses the ref. Finally, in the test file, we import the necessary modules and define a test for the `MyComponent` component.

Inside the test, we use the `jest.spyOn` method to spy on the `useRef` function. This allows us to track its usage and control its return value. Then, we mock the return value of the `useRef` function by using the `mockReturnValue` method on the spy. In this case, we are mocking the ref to have a `current` property with the value `”mockedRef”`. Next, we render the `MyComponent` component. Finally, we assert that the `useRef` function has been called with the expected arguments and clean up the spy using the `mockRestore` method.