feat(util): atomWithDefault

[dai-shi]

Close #352

• impl
• tests
• docs

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[aulneau]

This is a great helper, I was wondering if it makes sense to have atomFamilyWithDefault, too?

[dai-shi]

This is a great helper, I was wondering if it makes sense to have atomFamilyWithDefault, too?

tbh, i'm not very happy with it. we have atomWithReset too. we may have more helpers in the future.
I now think it's better if atomFamily takes atom creator instead of read/write.

const myFamily = atomFamily(param => atom(...))
// then this is possible
const myFamily = atomFamily(param => atomWithDefault(...))

what do you think? worth a breaking change before v1?

[aulneau]

what do you think? worth a breaking change before v1?

I do think so.

I have noticed that for any of the utility atoms, I've been needing to wrap them with other kinds. such as wishing i could do atomFamilyWithQuery. I could also see a need for something like this atomFamilyWithDefaultWithQuery lol (naming just for functional example)

[dai-shi]

Okay, the type would be much better too. Let's do that.
Would you or anyone like to work on it? I'm happy to take it if nobody raises a hand.
Maybe we want to create a dedicated issue at first.

[dai-shi]

Maybe we want to create a dedicated issue at first.

Done: #385

[dai-shi]

Thanks for the review. I will merge this later with others.