Support optimisticData as a function

[ludovic-montel]

First of all, thanks a lot for this library. I've been using it for almost a year, and more intensively for several months, and I love it!

Il like to create optimistic user interfaces, and the new optimisticData option with its auto-rollback behavior is great!

I'd like to push it a little further: could you support optimisticData as a function ? I think it would be consistent with the mutate first argument and with #1817.

This function would take the cached data as parameter, and would allow:

• using the global mutate function
• extracting and test a pure function that makes the mutation I want, depending on the current data and the operation that is processed

Again, thanks a lot for your work

[shuding]

Thanks for writing this, I created an issue to track the progress in #1858.

[shuding]

This feature is implemented in #1861 by @huozhi. 🎉

Will cut a beta release soon!

[ludovic-montel]

Thanks a lot! 🤩