react-native-performer

Zero-config rerender detection and overlay for React Native. Built for the new architecture (Fabric + Hermes).

Status: v0 work-in-progress. Not yet published to npm.

Why

• Zero instrumentation. No HOC, no hook, no babel plugin at your call sites — attaches to React's internal commit hook and walks the fiber tree.
• Visual feedback. Paints a flash overlay on any component that rerendered, with color-coded frequency.
• Built for RN. why-did-you-render is web-first and logs to console. React DevTools Profiler is manual and off by default. react-native-performer is RN-first, always-on in dev, and visual.

Requirements

• React Native with the new architecture enabled (Fabric)
• React >=18
• React Native >=0.74

Tested on Expo SDK 52+.

Install

TODO — not yet published.

npm install --save-dev react-native-performer

Usage

TODO — API in progress.

// Planned API, not yet implemented:
import 'react-native-performer/auto';

Roadmap

• Commit hook attachment + fiber walk (probe validated)
• Prop diff attribution (which prop changed, reference vs value)
• Host instance resolution + Reanimated-driven flash overlay
• Draggable HUD with top-N rerendering components
• Example Expo app demonstrating inline-object / missing-memo anti-patterns
• Opt-out filters (skip host components, skip navigation internals)
• Babel plugin for prod stripping

License

MIT © Viktor Krasnohorskiy