Optimistic update with useSWRMutation

[thebat93]

Bug report

Description / Observed Behavior

I'm trying to implement an optimistic update with useSWRMutation.
For some reason the data doesn't change optimistically. It is waiting for the fetcher resolve and then changes.
optimisticData is called, but it doesn't do anything.

Expected Behavior

Please see the attached example.
data should change rightaway to true when the button is clicked, but it is still undefined until the promise resolves.

Repro Steps / Code Example

https://codesandbox.io/p/sandbox/hopeful-bouman-cr27yt

Additional Context

SWR version: 2.2.5.
Add any other context about the problem here.

[MoSattler]

Same problem here! Did you find any solution?

[thebat93]

Hi! No, unfortunately I don't have any news