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Srikanth Kyatham
Srikanth Kyatham

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Rescript React Error boundary usage


I was trying to capture the react errors. I had to write the bindings for the ErrorBoundary and its usage is shown below.

The actual ErrorBoundary component is below

// ErrorBoundary.js
import React from "react";

class ErrorBoundary extends React.Component {
  constructor(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
    //logErrorToMyService(error, errorInfo);
    console.log({ error, errorInfo });

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

    return this.props.children;

export default ErrorBoundary;

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Bindings to the ErrorBoundary for Rescript.

// ReactErrorBoundary.res
@react.component @module("./ErrorBoundary.js")
external make: (
  ~children: React.element,
  ~onError: ('e, 'i) => unit=?,
  ~renderFallback: ('e, 'i) => React.element=?,
) => React.element = "ErrorBoundary"

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Error component to show the react error

// Error.res
module Error = {
  let make = (~error) => {
    <div> {React.string(error)} </div>

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How to use ReactErrorBoundary in rescript

// ReactErrorBoundary usage
<ReactErrorBoundary fallback={params => <Error 
  error=params.error />}>
  <ComponentThrowingException />
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