jest.setup.ts

import "@testing-library/jest-dom";

Object.defineProperty(window, "matchMedia", {
  writable: true,
  value: jest.fn().mockImplementation((query: string) => ({
    matches: false,
    media: query,
    onchange: null,
    addListener: jest.fn(),
    removeListener: jest.fn(),
    addEventListener: jest.fn(),
    removeEventListener: jest.fn(),
    dispatchEvent: jest.fn(),
  })),
});

global.IntersectionObserver = class IntersectionObserver {
  readonly root: Element | null = null;
  readonly rootMargin: string = "";
  readonly thresholds: ReadonlyArray<number> = [];
  private callback: IntersectionObserverCallback;
  constructor(callback: IntersectionObserverCallback, _?: IntersectionObserverInit) {
    this.callback = callback;
    setTimeout(() => {
      this.callback(
        [{ isIntersecting: true } as IntersectionObserverEntry],
        this as unknown as IntersectionObserver,
      );
    }, 0);
  }
  observe() {}
  unobserve() {}
  disconnect() {}
  takeRecords(): IntersectionObserverEntry[] {
    return [];
  }
};