onError in useMutation is muting errors

[kmdtqm]

We have a form that use optimistic updates with useMutation, where we use onError to roll back data in memory if it fails.

However onError seems to mute all errors, and does not rethrow them, which then breaks our forms that doesn't display any errors to the users, if there is a backend validation error.

The following code (from the top of my head) is basically what we are trying to accomplish (boiled down to bare minimum)

If onError is removed then the console.log in doSomething() is called..

function SomeTest() {
  const { mutateAsync } = useMutation({
     mutationFn: () => {
        throw new Error('something bad happened')
      },
      onError: (err) => {
        console.log(err)
      }
  })
  
  async function doSomething() {
     try {
        mutateAsync()
     } catch(err) {
        console.log('error should throw here', err)
     }
  }
 
  return <div><button onClick={() => doSomething()}>ClickME</button></div>
}

[kmdtqm]

Hmm.. looking further into this, something ain't right here.. Seems like we do get the error but somehow it is muted elsewhere outside useMutation scope..