question: stale while revalidate pattern in playground not descriptive enough

[niksy]

Question

It seems like SWR pattern in playground is not descriptive enough.

You get two fetcher calls, but cache hit for second call is result from the second call. Shouldn’t this be result from the first call?

I suppose you basically want to show stale data from first call while the second call is resolving, and then at the end it would be great to show another cache hit where result from the second call is visible, and so on.

EDIT: I just realized that this is possibly related to changes from seconds to milliseconds. Fetcher is originally called every 10 seconds, but values is right now set to behave like 10 milliseconds. This should be 10000.

[flyingsquirrel0419]

Resolved by PR #38 in commit b32836b.

The issue was caused by the playground SWR preset passing 10 as a TTL value, which the playground cache interpreted as 10 milliseconds, and by the mock cache not modeling a stale-while-revalidate window. The fix updates the preset to explicit millisecond options and teaches the playground mock cache to return stale data while refreshing in the background, then expose the refreshed value on the next read.

Regression coverage was added in docs-web/tests/playground-swr.test.ts.