Back to Repositories

Testing REST Parameters and Default Values Component in Create React App

This test suite validates the integration of REST parameters and default values in React components within Create React App. It ensures proper rendering and functionality of components utilizing modern JavaScript features like rest parameters and default value assignments.

Test Coverage Overview

The test coverage focuses on the fundamental rendering capabilities of components using REST parameters and default values.

Validates basic component mounting
Tests asynchronous rendering behavior
Verifies DOM integration
Ensures proper Promise resolution

Implementation Analysis

The testing approach utilizes Jest’s asynchronous testing capabilities combined with React’s rendering lifecycle. The implementation leverages Promise-based assertions to verify component mounting, employing ReactDOM.render with a callback pattern for completion verification.

Async/await pattern usage
Promise-based rendering validation
Component lifecycle hooks integration

Technical Details

Jest test runner
React Testing Library
ReactDOM rendering API
DOM manipulation utilities
Promise-based assertions
Component mounting verification

Best Practices Demonstrated

The test suite exemplifies clean testing practices by isolating component rendering and utilizing asynchronous patterns effectively. It demonstrates proper cleanup and setup procedures while maintaining clear test boundaries.

Isolated component testing
Asynchronous testing patterns
Clean setup/teardown
Clear test case organization

facebook/create-react-app

packages/react-scripts/fixtures/kitchensink/template/src/features/syntax/RestAndDefault.test.js

            
/**
 * Copyright (c) 2015-present, Facebook, Inc.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */

import React from 'react';
import ReactDOM from 'react-dom';
import RestAndDefault from './RestAndDefault';

describe('rest + default', () => {
  it('renders without crashing', () => {
    const div = document.createElement('div');
    return new Promise(resolve => {
      ReactDOM.render(<RestAndDefault onReady={resolve} />, div);
    });
  });
});