Rork App Quality Metrics 2026— Crashlytics, Instruments, and Android Vitals for Production

// components/ErrorBoundary.tsx
import React, { Component, ErrorInfo } from 'react';
import { View, Text, TouchableOpacity, StyleSheet } from 'react-native';
import crashlytics from '@react-native-firebase/crashlytics';
 
interface Props {
  children: React.ReactNode;
  screenName?: string;
}
interface State { hasError: boolean; error?: Error; }
 
export class ErrorBoundary extends Component<Props, State> {
  state: State = { hasError: false };
 
  static getDerivedStateFromError(error: Error): State {
    return { hasError: true, error };
  }
 
  componentDidCatch(error: Error, info: ErrorInfo): void {
    crashlytics().setAttribute(
      'component_stack',
      info.componentStack?.slice(0, 500) ?? 'unknown'
    );
    if (this.props.screenName) {
      crashlytics().setAttribute('error_boundary_screen', this.props.screenName);
    }
    crashlytics().recordError(error);
  }
 
  render() {
    if (this.state.hasError) {
      return (
        <View style={styles.container}>
          <Text style={styles.title}>Something went wrong</Text>
          <Text style={styles.message}>
            We've sent a report to fix this. Sorry for the trouble.
          </Text>
          <TouchableOpacity
            style={styles.button}
            onPress={() => this.setState({ hasError: false })}
          >
            <Text style={styles.buttonText}>Try again</Text>
          </TouchableOpacity>
        </View>
      );
    }
    return this.props.children;
  }
}

// app/_layout.tsx
const appStartTime = useRef<number>(Date.now());
 
useEffect(() => {
  const timeToInteractive = Date.now() - appStartTime.current;
 
  analytics().logEvent('app_launch_time', {
    time_to_interactive_ms: timeToInteractive,
    platform: Platform.OS,
    build_version: Constants.expoConfig?.version ?? 'unknown',
  });
 
  // Flag slow startups in Crashlytics for investigation
  if (timeToInteractive > 3000) {
    crashlytics().log(`Slow startup: ${timeToInteractive}ms`);
  }
}, []);

// Rork sometimes generates this — it causes a retain cycle
class ViewModel: ObservableObject {
    var timer: Timer?
    
    func startTimer() {
        // Strong capture of self keeps ViewModel alive forever
        timer = Timer.scheduledTimer(withTimeInterval: 1.0, repeats: true) { _ in
            self.update() // ← Problem
        }
    }
}
 
// Fix: weak capture
func startTimer() {
    timer = Timer.scheduledTimer(withTimeInterval: 1.0, repeats: true) { [weak self] _ in
        self?.update()
    }
}

// Use InteractionManager to defer work until animations complete
import { InteractionManager } from 'react-native';
 
async function processAfterAnimation(heavyWork: () => void): Promise<void> {
  await new Promise<void>((resolve) => {
    InteractionManager.runAfterInteractions(() => {
      resolve();
    });
  });
  heavyWork();
}
 
// For large datasets: process in chunks with yielding
async function processInChunks<T>(
  items: T[],
  processor: (item: T) => T,
  chunkSize = 100
): Promise<T[]> {
  const results: T[] = [];
  for (let i = 0; i < items.length; i += chunkSize) {
    results.push(...items.slice(i, i + chunkSize).map(processor));
    // Yield to the JS thread
    await new Promise(resolve => setTimeout(resolve, 0));
  }
  return results;
}

# .github/workflows/quality-gate.yml
name: App Quality Gate
 
on:
  push:
    branches: [main, 'release/*']
 
jobs:
  quality-check:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
 
      - uses: actions/setup-node@v4
        with:
          node-version: '20'
 
      - name: Install dependencies
        run: npm ci
 
      - name: TypeScript strict check
        run: npx tsc --noEmit
 
      - name: ESLint — no-any rule enforced
        run: npx eslint . --ext .ts,.tsx --rule '{"@typescript-eslint/no-explicit-any": "error"}'
 
      - name: Unit test coverage
        run: npx jest --coverage --coverageThreshold='{"global":{"lines":70}}'
 
      - name: Check production crash rate
        run: |
          CRASH_RATE=$(curl -sf \
            "https://firebaseappdistribution.googleapis.com/v1/projects/${FIREBASE_PROJECT}/apps/${FIREBASE_APP}/releases" \
            -H "Authorization: Bearer ${{ secrets.FIREBASE_TOKEN }}" \
            | jq -r '.releases[0].crashRate // "0"')
          echo "Current crash rate: ${CRASH_RATE}%"
          if awk "BEGIN{exit !($CRASH_RATE > 0.5)}"; then
            echo "❌ Crash rate ${CRASH_RATE}% exceeds 0.5% threshold"
            exit 1
          fi
          echo "✅ Crash rate within threshold"
        env:
          FIREBASE_PROJECT: ${{ secrets.FIREBASE_PROJECT_ID }}
          FIREBASE_APP: ${{ secrets.FIREBASE_APP_ID }}