react-use/tests/createBreakpoint.test.ts

import { act, renderHook } from '@testing-library/react-hooks';
import createBreakpoint from '../src/factory/createBreakpoint';

const useBreakpointA = createBreakpoint();
const useBreakpointB = createBreakpoint({ mobileM: 350, laptop: 1024, tablet: 768 });

const originalInnerWidth = window.innerWidth;
const changeInnerWidth = (value) =>
  Object.defineProperty(window, 'innerWidth', { writable: true, configurable: true, value });
const revert = () => changeInnerWidth(originalInnerWidth);

describe('createBreakpoint', () => {
  test('should use default', () => {
    const { result } = renderHook(() => useBreakpointA());
    act(() => {
      changeInnerWidth(100);
      window.dispatchEvent(new Event('resize'));
    });
    expect(result.current).toBe('tablet');

    act(() => {
      changeInnerWidth(200);
      window.dispatchEvent(new Event('resize'));
    });
    expect(result.current).toBe('tablet');

    act(() => {
      changeInnerWidth(1100);
      window.dispatchEvent(new Event('resize'));
    });
    expect(result.current).toBe('laptop');

    act(() => {
      changeInnerWidth(1500);
      window.dispatchEvent(new Event('resize'));
    });
    expect(result.current).toBe('laptopL');

    act(() => {
      revert();
    });
  });

  test('should use custom', () => {
    const { result } = renderHook(() => useBreakpointB());
    act(() => {
      changeInnerWidth(100);
      window.dispatchEvent(new Event('resize'));
    });
    expect(result.current).toBe('mobileM');

    act(() => {
      changeInnerWidth(200);
      window.dispatchEvent(new Event('resize'));
    });
    expect(result.current).toBe('mobileM');

    act(() => {
      changeInnerWidth(800);
      window.dispatchEvent(new Event('resize'));
    });
    expect(result.current).toBe('tablet');

    act(() => {
      changeInnerWidth(1100);
      window.dispatchEvent(new Event('resize'));
    });
    expect(result.current).toBe('laptop');

    act(() => {
      revert();
    });
  });
});