typescriptintermediate

Error Boundary with Fallback UI

Class-based error boundary component that catches render errors and displays a customizable fallback UI.

typescriptPress ⌘/Ctrl + Shift + C to copy

import React from 'react';

interface Props {
  children: React.ReactNode;
  fallback?: React.ReactNode;
}

interface State {
  hasError: boolean;
  error: Error | null;
}

export class ErrorBoundary extends React.Component<Props, State> {
  constructor(props: Props) {
    super(props);
    this.state = { hasError: false, error: null };
  }

  static getDerivedStateFromError(error: Error): State {
    return { hasError: true, error };
  }

  componentDidCatch(error: Error, info: React.ErrorInfo) {
    console.error('ErrorBoundary caught:', error, info.componentStack);
  }

  render() {
    if (this.state.hasError) {
      if (this.props.fallback) return this.props.fallback;
      return (
        <div role="alert" style={{ padding: 16 }}>
          <h2>Something went wrong</h2>
          <pre style={{ whiteSpace: 'pre-wrap' }}>
            {this.state.error?.message}
          </pre>
          <button onClick={() => this.setState({ hasError: false, error: null })}>
            Try again
          </button>
        </div>
      );
    }
    return this.props.children;
  }
}

// Usage:
// <ErrorBoundary fallback={<p>Oops!</p>}>
//   <RiskyComponent />
// </ErrorBoundary>