javascript - 创建根(...): Target container is not a DOM element in React Test file

Question

我在我的项目和测试文件中使用 React-18.0.0，我收到以下错误

createRoot(...): Target container is not a DOM element.

我的测试文件是:

import ReactDOM from 'react-dom/client';
import { render, screen } from "@testing-library/react";
import App from "./App";

const root = ReactDOM.createRoot(document.getElementById("root"));

test("renders learn react link", () => {
    root.render(<App />);
    const linkElement = screen.getByText(/Hello React/i);
    expect(linkElement).toBeInTheDocument();
});

Answer 1

你的 test使用 root.render(<App />)而 React 的 testing-library 提供自己的render在 test 中使用的函数

检索 root不需要，并且会导致您显示的错误。

因此，应用以下更改:

// Remove
root.render(<App />);

// Replace with
render(<App />);  // Imported from @testing-library/react

---

工作示例App.test.js :

import { render, screen } from '@testing-library/react';
import App from './App';

test('renders learn react link', () => {
    render(<App />);
    const linkElement = screen.getByText(/this should exist/i);
    expect(linkElement).toBeInTheDocument();
});