`populateCache` is being deferred when `mutate` is called multiple times

[henriqemalheiros]

Bug report

Description / Observed Behavior

I'm using the mutate function to partially update the cached data (like this second example). When starting a second mutation before the first mutation is finished, the populateCache of the first one is ignored. Because of this, when adding things to a list, the final result will be incomplete, since the first mutation couldn't update the cache.

Expected Behavior

populateCache is always called, in order in which the mutations were called.

Repro Steps / Code Example

• Open this sandbox;
• Quickly, click on "Add 5", "Add 6" and "Add 7";
• Although the items 5 and 6 are being added to the fake database, only item 7 is being displayed because the only populateCache that was called was the last one (you can check it in the console);
• If you change revalidate to true, the revalidation is deferred (as it should), and the list is complete. But I don't want to make an unnecessary revalidation if I have the means to sync the cached data to the latest data.

Additional Context

SWR version: 2.0.0-rc.0

[koba04]

Thank you for reporting the issue👍
Currently, swr ignores populateCache intentionally to avoid race conditions. So the result of the first mutation is ignored in this case. In order to fix this avoiding the race condition problem, we might have to enqueue populateCache and apply it in the right order.

[alexnsorensen]

Is there an update on getting this fixed as it's a bit of a deal breaker for me using this in my project.