Sample code

createResource({
  url: "https://example.com",
  auto: true,
  validate() {
    return "Sample error";
  },
  onError(error) {
    alert(error);
  },
});

Expected

One alert with 'Sample error'

Result

Gets two alerts with 'Sample error'

Possible cause

handleError is getting called twice from here. The second call might be due to error thrown from handleError

Possible fix

Remove error thrown from handleError?