ssr test html

app.spec.tsx

it('test SSR', async () => {
   const response = await request(app.callback()).get('/').send();

  expect(response.status).toBe(200);

  const { getByText } = renderHtml(response.text);

  expect(getByText('my data')).toBeTruthy();
});

renderHtml.tsx

import { prettyDOM, within } from '@testing-library/react';
import { JSDOM } from 'jsdom';

export const renderHtml = (html: string) => {
  const {
    window: { document },
  } = new JSDOM();

  const container = JSDOM.fragment(html);

  document.adoptNode(container);
  (container as any).outerHTML = html; // Fixes prettyDOM for container

  return {
    document,
    container,
    debug(el?: ParentNode) {
      if (el) {
        // eslint-disable-next-line
        console.log(prettyDOM(el as HTMLElement));
      } else {
        // eslint-disable-next-line
        console.log(
          ...[].map.call(container.children, (child: HTMLElement) =>
            prettyDOM(child),
          ),
        );
      }
    },
    ...within(container),
  };
};