LoginPage.test.js

import React from 'react';
import { act, renderHook } from '@testing-library/react-hooks'; // Don't forget to install this package
import { useValue } from "./useValue";

it("Custom hook hooks:)", () => {
    const { result } = renderHook(useValue);
    act(() => {
        result.current.assignValue('Hello World');
    });
    expect(result.current.value).toBe('Hello World');
});