ReactScope

Zero-dependency React performance profiler with micro-kernel plugin architecture.

Track renders, detect wasted updates, monitor memory, and optimize your React applications with a powerful micro-kernel plugin architecture.

Features

• Zero Dependencies - No runtime dependencies, everything implemented from scratch
• Render Tracking - Track every render with precise timing and phase detection
• Wasted Render Detection - Automatically detect unnecessary re-renders
• Props Diffing - Deep comparison of props between renders
• Memory Monitoring - Track heap usage and detect potential memory leaks
• Network Correlation - Correlate network requests with component renders
• Visual Dashboard - Real-time monitoring with Shadow DOM isolation
• Plugin Architecture - Extensible micro-kernel design
• TypeScript First - Full type safety with strict mode
• Tree Shakeable - Only include what you use

Installation

npm install @oxog/reactscope

yarn add @oxog/reactscope

pnpm add @oxog/reactscope

Quick Start

1. Wrap your app with the Provider

import { ReactScopeProvider } from '@oxog/reactscope'

function App() {
  return (
    <ReactScopeProvider>
      <YourApp />
    </ReactScopeProvider>
  )
}

2. Use the useScope hook to track components

import { useScope } from '@oxog/reactscope'

function MyComponent({ data }) {
  const scope = useScope('MyComponent')

  // Access metrics
  console.log('Renders:', scope.renderCount)
  console.log('Avg time:', scope.averageRenderTime)

  return <div>{data}</div>
}

3. Or wrap components with the Scope component

import { Scope } from '@oxog/reactscope'

function App() {
  return (
    <Scope name="ExpensiveList">
      <ExpensiveList items={items} />
    </Scope>
  )
}

4. Enable the Dashboard

import { ReactScopeProvider, createDashboardUIPlugin } from '@oxog/reactscope'

function App() {
  return (
    <ReactScopeProvider
      plugins={[createDashboardUIPlugin()]}
      onReady={(kernel) => {
        // Open with Ctrl+Shift+R or programmatically
        kernel.getPlugin('dashboard-ui')?.api.show()
      }}
    >
      <YourApp />
    </ReactScopeProvider>
  )
}

API Reference

Provider

<ReactScopeProvider
  enabled={true}                    // Enable/disable profiling
  plugins={[customPlugin]}          // Additional plugins
  onReady={(kernel) => {}}          // Callback when ready
  options={{
    trackAllComponents: false,      // Auto-track all components
    sampleRate: 1,                  // 0-1, for performance
    maxHistorySize: 1000,           // Limit stored events
  }}
>
  {children}
</ReactScopeProvider>

Hooks

// Main profiling hook
const scope = useScope('ComponentName', options)
scope.renderCount       // number
scope.lastRenderTime    // number (ms)
scope.averageRenderTime // number (ms)
scope.wastedRenders     // number

// Read-only metrics hook
const metrics = useScopeMetrics('ComponentId')

// Access kernel directly
const kernel = useScopeContext()

HOC

import { withScope } from '@oxog/reactscope'

const ProfiledComponent = withScope(MyComponent, {
  name: 'MyComponent',
  trackProps: true,
  onRender: (metrics) => console.log(metrics),
})

Plugins

ReactScope comes with 10 built-in plugins:

Plugin	Description
render-tracker	Tracks render count and duration
props-differ	Analyzes props changes between renders
wasted-render-detector	Detects unnecessary re-renders
lifecycle-tracker	Tracks mount/unmount events
console-reporter	Logs profiling data to console
json-exporter	Exports metrics as JSON
timeline-recorder	Records events for playback
memory-tracker	Monitors memory usage
network-correlator	Correlates renders with network requests
dashboard-ui	Visual overlay panel

Creating Custom Plugins

import { createPlugin } from '@oxog/reactscope'

const myPlugin = createPlugin({
  name: 'my-plugin',
  version: '1.0.0',
  hooks: {
    onRender: (event) => {
      console.log(`${event.componentName} rendered in ${event.duration}ms`)
    },
  },
  api: {
    customMethod: () => 'custom data',
  },
})

Programmatic API

import { getKernel, getMetrics, exportMetrics, clearMetrics } from '@oxog/reactscope'

// Access global kernel
const kernel = getKernel()

// Get metrics store
const metrics = getMetrics()

// Export as JSON
const json = exportMetrics()

// Clear all data
clearMetrics()

Browser Support

• Chrome 80+
• Firefox 75+
• Safari 14+
• Edge 80+

Performance

ReactScope is designed to have minimal impact on your application:

• Uses requestIdleCallback for non-critical updates
• Batches metric updates
• Throttles dashboard renders
• Supports sampling rate for high-frequency renders
• Lazy initializes plugins

License

MIT

Links

• Documentation
• GitHub Repository