catchError

catchError establishes an error boundary for work performed inside the provided function.

Import

import { catchError } from "solid-js";

Type

function catchError<T>(
  fn: () => T,
  handler: (err: Error) => void
): T | undefined;

Parameters

fn

• Type: () => T
• Required: Yes

Function executed inside the error boundary.

handler

• Type: (err: Error) => void
• Required: Yes

Error handler invoked when a thrown value reaches this boundary.

Return value

• Type: T | undefined

Returns the value produced by fn, or undefined when a thrown value is caught and handled.

Behavior

• While fn runs, catchError establishes an error boundary for reactive scopes created inside it.
• Only the nearest matching error boundary handles a thrown error.
• If handler throws, the next parent error boundary handles that error.

Examples

Handle an error in a child scope

import { catchError, createEffect, createSignal } from "solid-js";

function Example() {
  const [count, setCount] = createSignal(0);

  catchError(
    () => {
      createEffect(() => {
        if (count() > 2) throw new Error("count too large");
      });
    },
    (err) => {
      console.error(err.message);
    }
  );

  return <button onClick={() => setCount((c) => c + 1)}>Increment</button>;
}

Related

• ErrorBoundary
• createEffect