null/undefined initial atom value confuses typescript

Whenever I set null or undefined as the initial value on an atom, TypeScript infers the type as Atom instead of WritableAtom.

Working case: initial value is false so type is shown as WritableAtom:

Non-working case: initial value is null so type is just Atom:

This shows up as a type error on useUpdateAtom:

My current workaround: caste to PrimitiveAtom:

const myAtomConfig = atom<boolean | null>(null) as PrimitiveAtom<
  boolean | null
>;

[dai-shi]

The workaround for you should be explicit typing.

Can you give an example of what you mean?

Sorry, it’s not explicit typing, but type assertion. Like OP noted:

const myAtomConfig = atom<boolean | null>(null) as PrimitiveAtom<
  boolean | null
>;

[alexluong]

Just FYI I ended up setting struct: true as well, but I think it would be good to know the workaround if possible! Thanks for being very responsive and I really enjoy using jotai so far!