reactjs - can you catch all errors of a React.js app with a try/catch block?

Question

I've made a react application which is not running live, and the people that use it note that very occasionally some strange error occurs. I don't know why or what happens, and can't reproduce it.

So I'm wondering if there is a way to wrap the entire app, or parts of it, in a try/catch block so that I can send the errors to an error log on the server?

All I've read so far is that you could wrap the entire render function in a try/catch, but that would not catch any errors due to user interation right?

Answer 1

React 16 introduced Error Boundaries and the componentDidCatch lifecycle method:

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

  componentDidCatch(error, info) {
    // Display fallback UI
    this.setState({ hasError: true });
    // You can also log the error to an error reporting service
    logErrorToMyService(error, info);
  }

  render() {
    if (this.state.hasError) {
      // You can render any custom fallback UI
      return <h1>Something went wrong.</h1>;
    }
    return this.props.children;
  }
}

Then you can use it as a regular component:

<ErrorBoundary>
  <MyWidget />
</ErrorBoundary>

Or you can wrap your root component with the npm package react-error-boundary, and set a fallback component and behavior.

import {ErrorBoundary} from 'react-error-boundary';

const myErrorHandler = (error: Error, componentStack: string) => {
  // ...
};

<ErrorBoundary onError={myErrorHandler}>
  <ComponentThatMayError />
</ErrorBoundary>