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[READ-ONLY] Mirror of https://github.com/wojtekmaj/react-hooks. A collection of React Hooks.
hooks react react-hooks
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2.8 kB · 107 lines
TypeScript
at main
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';import { renderHook } from 'vitest-browser-react';import { act } from 'react';
import useIntersectionObserverRef from './useIntersectionObserverRef.js';
import type { Mock } from 'vitest';
const itIfWindowDefined = it.runIf(typeof window !== 'undefined');
async function waitForAsync() { await new Promise((resolve) => { setTimeout(resolve, 0); });}
describe('useIntersectionObserverRef()', () => { const config = {};
let observerCallback: IntersectionObserverCallback; let observer: IntersectionObserver; let observe: Mock; let disconnect: Mock;
beforeEach(() => { if (typeof window !== 'undefined') { observe = vi.fn(); disconnect = vi.fn();
function MockIntersectionObserver(callback: IntersectionObserverCallback) { observerCallback = callback; observer = { observe, unobserve: () => { // Intentionally empty }, disconnect, root: null, rootMargin: '', scrollMargin: '', thresholds: [], takeRecords: () => [], };
return observer; }
Object.defineProperty(window, 'IntersectionObserver', { configurable: true, enumerable: true, get: () => MockIntersectionObserver, });
vi.spyOn(window, 'IntersectionObserver'); } });
afterEach(() => { vi.clearAllMocks(); });
it('returns a ref callback and null initially', async () => { const { result } = await renderHook(() => useIntersectionObserverRef());
expect(result.current[0]).toBeInstanceOf(Function); expect(result.current[1]).toBe(null); });
itIfWindowDefined('observes the referenced element and returns its latest entry', async () => { const element = document.createElement('div'); const { result } = await renderHook(() => useIntersectionObserverRef(config));
act(() => { result.current[0](element); });
await waitForAsync();
expect(window.IntersectionObserver).toHaveBeenCalledTimes(1); expect(window.IntersectionObserver).toHaveBeenCalledWith(expect.any(Function), config); expect(observe).toHaveBeenCalledTimes(1); expect(observe).toHaveBeenCalledWith(element);
const rect = element.getBoundingClientRect(); const entry = { boundingClientRect: rect, intersectionRatio: 1, intersectionRect: rect, isIntersecting: true, rootBounds: null, target: element, time: 0, } satisfies IntersectionObserverEntry;
act(() => { observerCallback([entry], observer); });
expect(result.current[1]).toBe(entry);
act(() => { result.current[0](null); });
expect(result.current[1]).toBe(null); });});