React 测试库单元测试用例：无法在未安装的组件上找到节点

Question

I'm having issue with React Unit test cases.

React: v18.2 Node v18.8

Created custom function to render component with ReactIntl. If we use custom component in same file in two different test cases, the second test is failing with below error.

Unable to find node on an unmounted component.

at findCurrentFiberUsingSlowPath (node_modules/react-dom/cjs/react-dom.development.js:4552:13)
at findCurrentHostFiber (node_modules/react-dom/cjs/react-dom.development.js:4703:23)
at findHostInstanceWithWarning (node_modules/react-dom/cjs/react-dom.development.js:28745:21)
at Object.findDOMNode (node_modules/react-dom/cjs/react-dom.development.js:29645:12)
at Transition.performEnter (node_modules/react-transition-group/cjs/Transition.js:280:71)
at node_modules/react-transition-group/cjs/Transition.js:259:27

If I run in different files or test case with setTimeout it is working as expected and there is no error. Please find the other configs below. It is failing even it is same test case.

setUpIntlConfig();
beforeAll(() => server.listen());

afterEach(() => {
  server.resetHandlers();
});

afterAll(() => {
  jest.clearAllMocks();
  server.close();
  cleanup();
});

Intl Config:

export const setUpIntlConfig = () => {
  if (global.Intl) {
    Intl.NumberFormat = IntlPolyfill.NumberFormat;
    Intl.DateTimeFormat = IntlPolyfill.DateTimeFormat;
  } else {
    global.Intl = IntlPolyfill;
  }
};

export const RenderWithReactIntl = (component: any) => {
  return {
    ...render(
      <IntlProvider locale="en" messages={en}>
        {component}
      </IntlProvider>
    )
  };
};

I'm using msw as mock server. Please guide us, if we are missing any configs.

Test cases:

test('fire get resource details with data', async () => {
    jest.spyOn(SGWidgets, 'getAuthorizationHeader').mockReturnValue('test-access-token');

    process.env = Object.assign(process.env, { REACT_APP_DIAM_API_ENDPOINT: '' });

    RenderWithReactIntl(<AllocatedAccess diamUserId={diamUserIdWithData} />);
    await waitForElementToBeRemoved(() => screen.getByText(/loading data.../i));

    const viewResource = screen.getAllByText(/view resource/i);
    fireEvent.click(viewResource[0]);
    await waitForElementToBeRemoved(() => screen.getByText(/loading/i));

    const ownerName = screen.getByText(/benedicte masson/i);

    expect(ownerName).toBeInTheDocument();
  });
  
   test('fire get resource details with data----2', async () => {
    jest.spyOn(SGWidgets, 'getAuthorizationHeader').mockReturnValue('test-access-token');

    process.env = Object.assign(process.env, { REACT_APP_DIAM_API_ENDPOINT: '' });

    RenderWithReactIntl(<AllocatedAccess diamUserId={diamUserIdWithData} />);
    await waitForElementToBeRemoved(() => screen.getByText(/loading data.../i));

    const viewResource = screen.getAllByText(/view resource/i);
    fireEvent.click(viewResource[0]);
    await waitForElementToBeRemoved(() => screen.getByText(/loading/i));

    const ownerName = screen.getByText(/benedicte masson/i);

    expect(ownerName).toBeInTheDocument();
  });

Answer 1

Can you try these changes:

test('fire get resource details with data----2', async () => {
  jest.spyOn(SGWidgets, 'getAuthorizationHeader').mockReturnValue('test-access-token');

  process.env = Object.assign(process.env, { REACT_APP_DIAM_API_ENDPOINT: '' });

  RenderWithReactIntl(<AllocatedAccess diamUserId={diamUserIdWithData} />);
  await waitFor(() => expect(screen.getByText(/loading data.../i)).not.toBeInTheDocument());

  const viewResource = screen.getAllByText(/view resource/i);

  act(() => {
    fireEvent.click(viewResource[0]);
  });

  await waitFor(() => expect(screen.getByText(/loading/i)).not.toBeInTheDocument());

  expect(screen.getByText(/benedicte masson/i)).toBeVisible();
});

I've got into the habit of using act() when altering something that's visible on the screen. A good guide to here: https://testing-library.com/docs/guide-disappearance/

Using getBy* in the waitFor() blocks as above though, you may be better off specifically checking the text's non-existence.

Without seeing your code it's difficult to go any further. I always say keep tests short and simple, we're testing one thing. The more complex they get the more changes for unforeseen errors. It looks like you're rendering, awaiting a modal closure, then a click, then another modal closure, then more text on the screen. I'd split it into two or more tests.