🔍 React Render Measurement Tool

Measure React component rendering with precision 📊

Getting Started • Features • Documentation • Contributing

✨ What is it?

A powerful developer tool that helps you understand and optimize how your React components render during tests. Get detailed insights into render counts, component behavior, and performance metrics - all within your testing environment.

🚧 Beta Notice: This project is under active development and not yet available on npm. Stay tuned for the first release!

🎯 Key Features

• 📊 Precise Render Tracking: Count and analyze component renders with accuracy
• 🔄 Component Reference Tracking: Keep tabs on all rendered components
• 🎬 Scenario Testing: Measure performance during user interactions and state changes
• 📈 Detailed Metrics: Get comprehensive data about component updates and timing

🚀 Getting Started

1. Installation

Choose the package that matches your environment:

For React Web:

# npm
npm install @react-render-measurement-tool/react

# yarn
yarn add @react-render-measurement-tool/react

# pnpm
pnpm add @react-render-measurement-tool/react

For React Native:

# npm
npm install @react-render-measurement-tool/react-native

# yarn
yarn add @react-render-measurement-tool/react-native

# pnpm
pnpm add @react-render-measurement-tool/react-native

2. Setup

Add the setup file to your test configuration:

// In your Jest or Vitest setup
import '@react-render-measurement-tool/core/setup';

3. Usage

Import from the appropriate package based on your environment:

// For React Web
import { measure } from '@react-render-measurement-tool/react';

// For React Native
import { measure } from '@react-render-measurement-tool/react-native';

Here's a quick example of measuring render performance:

import userEvent from '@testing-library/user-event';
import { useState } from 'react';
import { measure } from '@react-render-measurement-tool/react';

it('tracks re-renders after state changes', async () => {
  const Counter = () => {
    const [count, setCount] = useState(0);
    return (
      <button onClick={() => setCount(v => v + 1)}>
        Count: {count}
      </button>
    );
  };

  const result = await measure(<Counter />, {
    scenario: async (screen) => {
      await userEvent.click(screen.getByRole('button'));
    },
  });

  expect(result.commits).toHaveLength(2); // Initial render + click update
});

📦 Package Structure

The tool consists of three packages:

• @react-render-measurement-tool/core: Core functionality and DevTools integration
• @react-render-measurement-tool/react: React Web specific implementation
• @react-render-measurement-tool/react-native: React Native specific implementation

📖 API Reference

measure(ui, options)

Measures rendering performance of a React component.

Parameters:

• ui: ReactElement - The component to measure
• options: (Optional)
  • scenario: Function to execute actions after initial render

Returns:

• Promise<MeasureResult> containing:
  • commits: Detailed render information
  • rawProfilingData: Raw performance metrics
  • exportProfilingData: Function to export DevTools-compatible data

🤝 Contributing

We love contributions! Whether it's:

• 🐛 Bug reports
• 💡 Feature suggestions
• 📝 Documentation improvements
• 🔧 Code contributions

Feel free to open an issue or submit a PR!

📄 License

MIT Licensed. See LICENSE for details.