Function assertNamespacesMatch

packages/react-dom/src/__tests__/ReactDOMFiber-test.js:191–213

(tree)

  };

  const assertNamespacesMatch = async function (tree) {
    const testContainer = document.createElement('div');
    svgEls = [];
    htmlEls = [];
    mathEls = [];

    const testRoot = ReactDOMClient.createRoot(testContainer);
    await act(async () => {
      testRoot.render(tree);
    });
    svgEls.forEach(el => {
      expect(el.namespaceURI).toBe('http://www.w3.org/2000/svg');
    });
    htmlEls.forEach(el => {
      expect(el.namespaceURI).toBe('http://www.w3.org/1999/xhtml');
    });
    mathEls.forEach(el => {
      expect(el.namespaceURI).toBe('http://www.w3.org/1998/Math/MathML');
    });

    testRoot.unmount();
    expect(testContainer.innerHTML).toBe('');
  };

  it('should render one portal', async () => {
    const portalContainer = document.createElement('div');