type of data only promise atoms and injectAtomValue

[joprice]

I'm finding that I get unexpected runtime failures due to undefined being returned from a injectAtomValue call that is provided a dataOnly atom. I'm wondering first if I'm doing something wrong, and then if this could be detected at compile time by altering the overloads of injectAtomValue. I haven't dug into how dataOnly swizzles the types so not sure enough state is stored in the types to distinguish calling useAtomValue, where suspense will ensure the nullable value is resolved and injectAtomValue, where is should be treated as possibly undefined.

[bowheart]

@joprice you're right. dataOnly's types are wrong - T instead of T | undefined. Our injectPromise usages are very simple - in fact I only see one usage of dataOnly that apparently didn't run into this. Thanks for reporting.

injectAtomValue vs useAtomValue is a good point too. It would be nice if we could detect that suspense will make a value non-nullable.

Let me think about this for a minute.

[bowheart]

@joprice I created #220 to discuss/track this injectPromise fix and improvement along with other injectPromise and query atom changes I've been thinking about.