@react-buoy/debug-borders

A visual layout debugging tool for React Native that highlights components with colored borders and labels. Features three display modes, smart filtering to show only meaningful components, and tap-to-inspect functionality. Works with Expo, React Native CLI, and supports both the new architecture (Fabric) and legacy architecture.

Features

- Three Display Modes: Cycle through Off → Borders → Labels with a single tap
- Smart Filtering: Only shows borders/labels for components with testID or accessibilityLabel
- Tap-to-Inspect: Tap any label to see detailed component information in a modal
- Color-Coded Labels: Labels match border colors based on identifier type (testID = green, accessibilityLabel = pink)
- Label Stacking: Overlapping labels automatically stack upward like a menu
- Hidden Screen Detection: Automatically hides borders on inactive screens in stack navigators
- DevTools Aware: Hides borders when DevTools modals are open
- Real-Time Updates: Automatically tracks layout changes (updates every 2 seconds)
- Touch-Through: Borders don't interfere with touch interactions
- Performance Optimized: Minimal impact (~30ms to measure 400+ components)

Installation

``bash
npm install @react-buoy/debug-borders


or

pnpm add @react-buoy/debug-borders

or

yarn add @react-buoy/debug-borders
`

Quick Start

`tsx
import { debugBordersToolPreset, DebugBordersStandaloneOverlay } from '@react-buoy/debug-borders';
import { FloatingDevTools } from '@react-buoy/core';

const installedApps = [
debugBordersToolPreset, // Add the tool to your menu
// ...your other tools
];

function App() {
return (
<>
apps={installedApps}
environment="local"
userRole="admin"
/>

{/ IMPORTANT: Render overlay at root level /}


{/ Your app content /}


);
}
`

Done! Tap the BORDERS icon in the floating menu to cycle through modes.

Display Modes

The tool cycles through three modes when you tap the icon:

| Mode | Icon Color | Description |
|------|------------|-------------|
| Off | Gray | No borders displayed |
| Borders | Green | Rainbow-colored borders for all components (depth-based colors) |
| Labels | Cyan | Borders + labels only for components with testID or accessibilityLabel |

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In Labels mode, the tool provides focused debugging:

- Only shows components with identifiers - Components with testID or accessibilityLabel get borders and labels
- Color-coded by identifier type:
- 🟢 Green = testID
- 🩷 Pink = accessibilityLabel
- Labels positioned above boxes - Easy to read without obscuring content
- Automatic stacking - Overlapping labels stack upward like a menu
- Tap to inspect - Tap any label to see full component details

Tap-to-Inspect Modal

Tap any label in Labels mode to open a detailed inspection modal showing:

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- testID (green)
- accessibilityLabel (pink)
- nativeID (amber)
- key

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- Component Name (the React component that rendered this)
- Parent Component
- Display Name (friendly name like "View", "Text")
- Native View Type (e.g., "RCTView", "RCTText")
- Fiber Tag

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- X, Y coordinates
- Width, Height
- Depth in component tree

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- Role
- Hint
- State (displayed with interactive DataViewer)

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- Full computed styles (displayed with interactive DataViewer)

Usage Examples

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`tsx
import { debugBordersToolPreset, DebugBordersStandaloneOverlay } from '@react-buoy/debug-borders';

// Add to your FloatingDevTools apps array
const installedApps = [debugBordersToolPreset];

// Render overlay at root level


// Tap the BORDERS icon to cycle: Off → Borders → Labels → Off
`

$3

`tsx
import { createDebugBordersTool, DebugBordersStandaloneOverlay } from '@react-buoy/debug-borders';

const customBordersTool = createDebugBordersTool({
name: "LAYOUT",
description: "Layout visualizer",
offColor: "#9ca3af", // Gray when off
bordersColor: "#ec4899", // Pink in borders mode
labelsColor: "#8b5cf6", // Purple in labels mode
id: "custom-borders",
});

const installedApps = [customBordersTool];
`

$3

`tsx
import { DebugBordersManager, DebugBordersStandaloneOverlay } from '@react-buoy/debug-borders';

// Get current mode
const mode = DebugBordersManager.getMode(); // "off" | "borders" | "labels"

// Set specific mode
DebugBordersManager.setMode("borders");
DebugBordersManager.setMode("labels");
DebugBordersManager.setMode("off");

// Cycle to next mode
DebugBordersManager.cycle(); // off → borders → labels → off

// Check if labels should be shown
const showLabels = DebugBordersManager.showLabels(); // true when mode is "labels"

// Subscribe to mode changes
const unsubscribe = DebugBordersManager.subscribe((mode) => {
console.log('Mode changed to:', mode);
});

// Clean up
unsubscribe();
`

API Reference

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#### debugBordersToolPreset

Pre-configured tool for FloatingDevTools. Shows only in the floating menu (not the dial).

`tsx
import { debugBordersToolPreset } from '@react-buoy/debug-borders';

const installedApps = [debugBordersToolPreset];
`

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#### createDebugBordersTool(options?)

Create a custom debug borders tool configuration.

Options:
- name?: string - Tool name (default: "BORDERS")
- description?: string - Tool description
- offColor?: string - Icon color when off (default: "#6b7280" gray)
- bordersColor?: string - Icon color in borders mode (default: "#10b981" green)
- labelsColor?: string - Icon color in labels mode (default: "#06b6d4" cyan)
- id?: string - Custom tool ID (default: "debug-borders")

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####

The main overlay component that renders borders and labels. Must be rendered at root level.

`tsx
import { DebugBordersStandaloneOverlay } from '@react-buoy/debug-borders';


`

Note: This component must be rendered at the root level of your app, outside all modals and navigation containers, for borders to appear on top of everything.

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#### DebugBordersManager

Global state manager for controlling debug borders.

Methods:
- getMode(): "off" | "borders" | "labels" - Get current display mode
- setMode(mode) - Set display mode
- cycle() - Cycle to next mode (off → borders → labels → off)
- showLabels(): boolean - Check if labels should be shown (mode === "labels")
- subscribe(callback: (mode) => void): () => void - Subscribe to mode changes

How It Works

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The tool intelligently filters what it displays:

1. Hidden Screen Detection - Skips components in inactive screens (React Navigation stack)
2. SVG Filtering - Excludes SVG elements (RNSVG* components)
3. DevTools Filtering - Excludes FloatingDevTools, modals, and other dev tool components
4. Identifier Filtering (Labels mode) - Only shows components with testID or accessibilityLabel

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Labels are positioned above their component boxes and automatically stack when they would overlap:

`
┌─────────────────────────────────────┐
│ [submitButton] │ ← Labels stack upward
│ [formContainer] │
├─────────────────────────────────────┤
│ │
│ Component Content │
│ │
└─────────────────────────────────────┘
`

$3

Borders Mode - Colors based on nesting depth using golden angle (137.5°):
| Depth | Color |
|-------|-------|
| 0 | Red-Orange |
| 1 | Green |
| 2 | Blue |
| 3+ | Continues with golden angle |

Labels Mode - Colors based on identifier type:
| Identifier | Color |
|------------|-------|
| testID | Green (#10b981) |
| accessibilityLabel | Pink (#ec4899) |
| componentName | Purple (#a855f7) |
| nativeID | Amber (#f59e0b) |
| viewType (fallback) | Gray (#6b7280) |

Performance

- Measurement Time: ~30ms for 400+ components
- Update Frequency: Every 2 seconds when enabled
- Memory Impact: Minimal (only stores rectangle data)
- Runtime Impact: Zero when disabled
- Label Positioning: O(n²) worst case, optimized with early exits

Compatibility

- React Native >= 0.70.0
- Fabric (New Architecture)
- Paper (Legacy Architecture)
- Expo
- React Native CLI

Troubleshooting

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1. Make sure DebugBordersStandaloneOverlay is rendered at root level
2. Tap the icon to cycle modes - you may be in "off" mode
3. In Labels mode, borders only show for components with testID or accessibilityLabel
4. Verify you're in development mode (__DEV__ is true)

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Labels are positioned above component boxes. If they still overlap, they automatically stack upward. Very dense UIs may have many stacked labels.

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Make sure you're in Labels mode (cyan icon). In Borders mode, labels aren't shown and tapping doesn't work.

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The inspection modal uses the standard JsModal component. Swipe up to expand it or drag the handle to resize.

Structure

`
debug-borders/
├── src/
│ ├── index.tsx # Main exports
│ ├── preset.tsx # Preset configuration
│ └── debug-borders/
│ ├── components/
│ │ └── DebugBordersStandaloneOverlay.tsx
│ └── utils/
│ ├── DebugBordersManager.js # State manager (3 modes)
│ ├── fiberTreeTraversal.js # Fiber traversal + filtering
│ ├── componentMeasurement.js # Component measurements
│ ├── componentInfo.js # Label extraction
│ ├── labelPositioning.js # Overlap resolution
│ ├── ViewTypeMapper.ts # Native → friendly names
│ └── colorGeneration.js # Color generation
├── package.json
└── README.md
``

License

MIT