使用方法
- 复制安装命令，在自己的智能体环境安装前先检查源码包。
- 从原始文档核对所需工具、凭据和支持的宿主。
- 说明输入材料与期望交付物，并对照来源检查输出。
npx skills add https://github.com/majesticlabs-dev/majestic-marketplace --skill react-testing开始前需了解
- 安装不包含模型订阅、API 额度或访问文件的权限。
- 仓库星数和安装量反映活跃情况，不等于独立质量或安全测试。
仓库原始内容
按源仓库内容呈现，保留标题、案例、代码、表格、链接以及原文引用的演示图片。
React Testing
Overview
This skill provides comprehensive guidance for testing React applications using Vitest, React Testing Library, and Jest. Apply these patterns when writing unit tests, integration tests, and ensuring code quality.
Core Philosophy
- Test behavior, not implementation: Focus on what users see and do
- Avoid testing internal state: Test public APIs and user interactions
- Write tests that give confidence: Catch real bugs, not false positives
- Keep tests simple: Tests should be easier to understand than the code
Testing Tools
Vitest Configuration
ts
// vitest.config.ts
import { defineConfig } from 'vitest/config';
import react from '@vitejs/plugin-react';
export default defineConfig({
plugins: [react()],
test: {
globals: true,
environment: 'jsdom',
setupFiles: './src/test/setup.ts',
coverage: {
provider: 'v8',
reporter: ['text', 'json', 'html'],
exclude: ['node_modules/', 'src/test/']
}
}
});Test Setup
ts
// src/test/setup.ts
import { expect, afterEach } from 'vitest';
import { cleanup } from '@testing-library/react';
import * as matchers from '@testing-library/jest-dom/matchers';
expect.extend(matchers);
afterEach(() => {
cleanup();
});Component Testing
Basic Component Test
tsx
import { render, screen } from '@testing-library/react';
import { expect, test } from 'vitest';
import { Button } from './Button';
test('renders button with label', () => {
render(<Button label="Click me" onClick={vi.fn()} />);
expect(screen.getByText('Click me')).toBeInTheDocument();
});
test('calls onClick when clicked', async () => {
const handleClick = vi.fn();
render(<Button label="Click me" onClick={handleClick} />);
await userEvent.click(screen.getByRole('button'));
expect(handleClick).toHaveBeenCalledTimes(1);
});
test('is disabled when prop is set', () => {
render(<Button label="Click me" onClick={vi.fn()} disabled />);
expect(screen.getByRole('button')).toBeDisabled();
});Form Testing
tsx
import { render, screen, waitFor } from '@testing-library/react';
import userEvent from '@testing-library/user-event';
import { LoginForm } from './LoginForm';
test('submits form with email and password', async () => {
const handleSubmit = vi.fn();
render(<LoginForm onSubmit={handleSubmit} />);
await userEvent.type(screen.getByLabelText('Email'), 'user@example.com');
await userEvent.type(screen.getByLabelText('Password'), 'password123');
await userEvent.click(screen.getByRole('button', { name: 'Login' }));
await waitFor(() => {
expect(handleSubmit).toHaveBeenCalledWith({
email: 'user@example.com',
password: 'password123'
});
});
});
test('shows validation error for invalid email', async () => {
render(<LoginForm onSubmit={vi.fn()} />);
await userEvent.type(screen.getByLabelText('Email'), 'invalid-email');
await userEvent.click(screen.getByRole('button', { name: 'Login' }));
expect(await screen.findByText('Invalid email address')).toBeInTheDocument();
});Hook Testing
Custom Hook Test
tsx
import { renderHook, act } from '@testing-library/react';
import { expect, test } from 'vitest';
import { useCounter } from './useCounter';
test('increments counter', () => {
const { result } = renderHook(() => useCounter());
expect(result.current.count).toBe(0);
act(() => {
result.current.increment();
});
expect(result.current.count).toBe(1);
});
test('decrements counter', () => {
const { result } = renderHook(() => useCounter(10));
act(() => {
result.current.decrement();
});
expect(result.current.count).toBe(9);
});Hook with Dependencies
tsx
import { renderHook, waitFor } from '@testing-library/react';
import { useApi } from './useApi';
test('fetches data successfully', async () => {
global.fetch = vi.fn(() =>
Promise.resolve({
ok: true,
json: () => Promise.resolve({ name: 'John' })
})
) as any;
const { result } = renderHook(() => useApi('/api/user'));
expect(result.current.loading).toBe(true);
await waitFor(() => {
expect(result.current.loading).toBe(false);
});
expect(result.current.data).toEqual({ name: 'John' });
expect(result.current.error).toBeNull();
});
test('handles error', async () => {
global.fetch = vi.fn(() =>
Promise.reject(new Error('Network error'))
);
const { result } = renderHook(() => useApi('/api/user'));
await waitFor(() => {
expect(result.current.error).toBeTruthy();
});
expect(result.current.data).toBeUndefined();
});Integration Testing
With Context
tsx
import { render, screen } from '@testing-library/react';
import { AuthProvider } from './AuthContext';
import { Dashboard } from './Dashboard';
const renderWithAuth = (ui: ReactElement, { user = null } = {}) => {
return render(
<AuthProvider value={{ user }}>
{ui}
</AuthProvider>
);
};
test('shows dashboard when authenticated', () => {
renderWithAuth(<Dashboard />, { user: { name: 'John' } });
expect(screen.getByText('Welcome, John')).toBeInTheDocument();
});
test('redirects to login when not authenticated', () => {
renderWithAuth(<Dashboard />);
expect(screen.queryByText('Welcome')).not.toBeInTheDocument();
});With Router
tsx
import { render, screen } from '@testing-library/react';
import { MemoryRouter } from 'react-router-dom';
import { App } from './App';
test('navigates to profile page', async () => {
render(
<MemoryRouter initialEntries={['/profile']}>
<App />
</MemoryRouter>
);
expect(screen.getByText('User Profile')).toBeInTheDocument();
});Mocking
API Mocking
tsx
import { rest } from 'msw';
import { setupServer } from 'msw/node';
const server = setupServer(
rest.get('/api/users', (req, res, ctx) => {
return res(
ctx.json([
{ id: '1', name: 'John' },
{ id: '2', name: 'Jane' }
])
);
})
);
beforeAll(() => server.listen());
afterEach(() => server.resetHandlers());
afterAll(() => server.close());
test('displays users from API', async () => {
render(<UserList />);
expect(await screen.findByText('John')).toBeInTheDocument();
expect(await screen.findByText('Jane')).toBeInTheDocument();
});Component Mocking
tsx
import { vi } from 'vitest';
vi.mock('./HeavyComponent', () => ({
HeavyComponent: () => <div>Mocked Component</div>
}));
test('renders page with mocked component', () => {
render(<Dashboard />);
expect(screen.getByText('Mocked Component')).toBeInTheDocument();
});Accessibility Testing
tsx
import { axe, toHaveNoViolations } from 'jest-axe';
expect.extend(toHaveNoViolations);
test('has no accessibility violations', async () => {
const { container } = render(<LoginForm onSubmit={vi.fn()} />);
const results = await axe(container);
expect(results).toHaveNoViolations();
});Best Practices
- Use semantic queries:
getByRole,getByLabelTextovergetByTestId - Test user behavior: Click, type, navigate like users do
- Avoid implementation details: Don't test state or props directly
- Use `findBy` for async: Automatically waits for elements
- Clean up: Use
afterEach(cleanup)to reset DOM - Mock external dependencies: APIs, timers, modules
- Test error states: Loading, error, empty states
- Keep tests focused: One assertion per test when possible
- Use descriptive test names: Describe what should happen
- Run tests in CI/CD: Ensure tests pass before deployment
