Add Custom Error Pages

[barziahmed]

Add support for custom error pages, similar to of Next.js error.js

[natew]

One already supports custom error handling via the ErrorBoundary export from route files. You can export an ErrorBoundary component from any page file:

// app/some-page.tsx
import { ErrorBoundaryProps } from 'one'

export function ErrorBoundary({ error, retry }: ErrorBoundaryProps) {
  return (
    <div>
      <h1>Something went wrong</h1>
      <p>{error.message}</p>
      <button onClick={retry}>Try again</button>
    </div>
  )
}

export default function Page() {
  // ...
}

This is similar to Next.js's error.js but uses an export instead of a separate file. The ErrorBoundaryProps type provides error and retry props.

If the request is specifically for a separate +error.tsx file convention (similar to +not-found.tsx), that would be a feature enhancement.