Server action mutation doesn't flush updates until the action finishes

[keyz]

Bug report

Description / Observed Behavior

(see repro below)

I'm experimenting with using (abusing? 🤔) a server action as a mutation fetcher, and I found that a server action mutation doesn't flush updates until the action finishes.

My hypothesis is it probably has something to do with both swr and React marking the update as a transition, therefore starving the update, but I haven't got to the bottom of it yet; wanted to open an issue early to see if y'all have any feedback/thoughts.

Expected Behavior

The mutation should flush an isMutating update immediately

Repro Steps / Code Example

https://codesandbox.io/p/sandbox/determined-dubinsky-wgf568?file=%2Fsrc%2Fapp%2Fpage.tsx%3A17%2C19

• The first "trigger" button doesn't flush updates until the action finishes
• The second "trigger" updates isMutating immediately as expected

Additional Context

Tested on latest canary versions:

• swr: 2.2.0-beta.0
• next: 13.4.5-canary.4

[promer94]

Thanks for your repro !

[keyz]

Thanks for the quick turnaround @promer94 -- would love to see a new beta release :)

[promer94]

We have a plan to release a new version in this week.

You could use codesandbox ci build in case you need it now 😁

[keyz]

Amazing, thank you!

[huozhi]

Reopen this issue as reverted in #2681
x-ref: #2654 (comment)