Reactのエラーハンドリング：グローバルアプリケーションのためのエラー境界と回復戦略

            
class ErrorBoundary extends React.Component {
  constructor(props) {
    super(props);
    this.state = { hasError: false };
  }

  static getDerivedStateFromError(error) {
    // Update state so the next render will show the fallback UI.
    return { hasError: true };
  }

  componentDidCatch(error, errorInfo) {
    // You can also log the error to an error reporting service
    console.error("Caught error: ", error, errorInfo);
    // Example: logErrorToMyService(error, errorInfo);
  }

  render() {
    if (this.state.hasError) {
      // You can render any custom fallback UI
      return (
        

          
Something went wrong.
          

            {this.state.error && this.state.error.toString()}
            

            {this.state.errorInfo && this.state.errorInfo.componentStack}
          
        
      );
    }

    return this.props.children; 
  }
}

            

              
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const handleClick = () => {
  try {
    // Risky operation
    doSomethingThatMightFail();
  } catch (error) {
    console.error("An error occurred: ", error);
    // Handle the error, e.g., display an error message
    setErrorMessage("An error occurred. Please try again later.");
  }
};

            

              
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import i18n from './i18n'; // Assuming you have i18next configured

const handleClick = () => {
  try {
    // Risky operation
    doSomethingThatMightFail();
  } catch (error) {
    console.error("An error occurred: ", error);
    // Use i18next to translate the error message
    setErrorMessage(i18n.t('errorMessage.generic')); // 'errorMessage.generic' is a key in your translation file
  }
};

            

              
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const fetchData = async () => {
  try {
    const response = await fetch('https://api.example.com/data');
    if (!response.ok) {
      throw new Error(`HTTP error! status: ${response.status}`);
    }
    const data = await response.json();
    setData(data);
  } catch (error) {
    console.error("Fetch error: ", error);
    setErrorMessage("Failed to fetch data. Please check your connection or try again later.");
  }
};

// Alternative with Promises:
fetch('https://api.example.com/data')
  .then(response => {
    if (!response.ok) {
      throw new Error(`HTTP error! status: ${response.status}`);
    }
    return response.json();
  })
  .then(data => {
    setData(data);
  })
  .catch(error => {
    console.error("Fetch error: ", error);
    setErrorMessage("Failed to fetch data. Please check your connection or try again later.");
  });

            

              
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import * as Sentry from "@sentry/react";
import { BrowserTracing } from "@sentry/tracing";

Sentry.init({
  dsn: "YOUR_SENTRY_DSN", // Replace with your Sentry DSN
  integrations: [new BrowserTracing()],

  // Set tracesSampleRate to 1.0 to capture 100%
  // of transactions for performance monitoring.
  // We recommend adjusting this value in production
  tracesSampleRate: 0.2,
  environment: process.env.NODE_ENV,
  release: "your-app-version",
});

const logErrorToSentry = (error, errorInfo) => {
  Sentry.captureException(error, { extra: errorInfo });
};

class ErrorBoundary extends React.Component {
  // ... (rest of the ErrorBoundary component)

  componentDidCatch(error, errorInfo) {
    logErrorToSentry(error, errorInfo);
  }
}

            

              
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const MyComponent = () => {
  const [data, setData] = React.useState(null);
  const [error, setError] = React.useState(null);
  const [loading, setLoading] = React.useState(true);

  React.useEffect(() => {
    fetchData()
      .then(result => {
        setData(result);
        setLoading(false);
      })
      .catch(err => {
        setError(err);
        setLoading(false);
      });
  }, []);

  if (loading) {
    return 
Loading...
;
  }

  if (error) {
    return (
      

        
Error: {error.message}
        
Please try again later.
         window.location.reload()}>Retry
      
    );
  }

  return 
Data: {JSON.stringify(data)}
;
};

            

              
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import axios from 'axios';
import axiosRetry from 'axios-retry';

axiosRetry(axios, { retries: 3 });

const fetchData = async () => {
  try {
    const response = await axios.get('https://api.example.com/data');
    return response.data;
  } catch (error) {
    console.error("Fetch error: ", error);
    throw error; // Re-throw the error so the calling component can handle it
  }
};

            

              
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import LaunchDarkly from 'launchdarkly-js-client-sdk';

const ldclient = LaunchDarkly.init('YOUR_LAUNCHDARKLY_CLIENT_ID', { key: 'user123' });

const MyComponent = () => {
  const [isNewFeatureEnabled, setIsNewFeatureEnabled] = React.useState(false);

  React.useEffect(() => {
    ldclient.waitForInit().then(() => {
      setIsNewFeatureEnabled(ldclient.variation('new-feature', false));
    });
  }, []);

  if (isNewFeatureEnabled) {
    return ;
  } else {
    return ;
  }
};

            

              
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import * as Yup from 'yup';

const schema = Yup.object().shape({
  email: Yup.string().email('Invalid email').required('Required'),
  password: Yup.string().min(8, 'Password must be at least 8 characters').required('Required'),
});

const MyForm = () => {
  const [email, setEmail] = React.useState('');
  const [password, setPassword] = React.useState('');
  const [errors, setErrors] = React.useState({});

  const handleSubmit = async (e) => {
    e.preventDefault();

    try {
      await schema.validate({ email, password }, { abortEarly: false });
      // Submit the form
      console.log('Form submitted successfully!');
    } catch (err) {
      const validationErrors = {};
      err.inner.forEach(error => {
        validationErrors[error.path] = error.message;
      });
      setErrors(validationErrors);
    }
  };

  return (
    

      

        Email:
         setEmail(e.target.value)} />
        {errors.email && 
{errors.email}
}
      
      

        Password:
         setPassword(e.target.value)} />
        {errors.password && 
{errors.password}
}
      
      Submit
    
  );
};

            

              
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