Feature request: Return stale value while revalidating

[futpib]

When used with maxAge option, when the cache entry has expired, memoized function could return last cached value while waiting for a new result to arrive.

[papb]

I think this could be an option, but not on by default.

[sindresorhus]

Yeah, sounds useful as an opt-in option.

[AmrSaber]

Hello @sindresorhus, I am interested in helping out with this feature. How can I help with it?

[Richienb]

@AmrSaber PRs are always welcome

[AmrSaber]

I don't understand how #26 closes this ticket? How do we achieve the stale-while-revalidate scenario now?

[Richienb]

#26 Moves this feature into userland.

[AmrSaber]

Can you show an example of how to achieve this?

[Richienb]

False alarm: after the previous PR, I'm not sure how to check if a value is stale anymore to then call the function again.

[futpib]

Should this be reopened then?

[Richienb]

Yes, but with the new goal of adding an API to the cache storage object to check whether the object is stale and whether stale-while-revalidate should be used