archive-gh-me/zustand
1
0
Fork 0
mirror of https://github.com/pmndrs/zustand.git synced 2025-12-08 19:45:52 +00:00
Code Issues Projects Releases Wiki Activity

docs: fix typos in the typescript guide (#2550)

Browse Source
This commit is contained in:
StyleShit 2024-05-13 11:47:11 +03:00 committed by GitHub
parent 6d6383054f
commit 11cc9c3c5e
No known key found for this signature in database
GPG Key ID: B5690EEEBB952194
1 changed files with 2 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
docs/guides/typescript.md
View File

@ -80,9 +80,9 @@ const useBoundStore = create<{ foo: number }>()((_, get) => ({
This code compiles. But if we run it, we'll get an exception: "Uncaught TypeError: Cannot read properties of undefined (reading 'foo')". This is because `get` would return `undefined` before the initial state is created (hence you shouldn't call `get` when creating the initial state). The types promise that `get` will never return `undefined` but it does initially, which means Zustand failed to implement it.
And of course Zustand failed because it's impossible to implement `create` the way types promise (in the same way it's impossible to implement `createFoo`). In other words we don't have a type to express the actual `create` we have implemented. We can't type `get` as `() => T | undefined` because it would cause inconveince and it still won't be correct as `get` is indeed `() => T` eventually, just if called synchronously it would be `() => undefined`. What we need is some kind of TypeScript feature that allows us to type `get` as `(() => T) & WhenSync<() => undefined>`, which of course is extremly far-fetched.
And of course Zustand failed because it's impossible to implement `create` the way types promise (in the same way it's impossible to implement `createFoo`). In other words we don't have a type to express the actual `create` we have implemented. We can't type `get` as `() => T | undefined` because it would cause inconvenience and it still won't be correct as `get` is indeed `() => T` eventually, just if called synchronously it would be `() => undefined`. What we need is some kind of TypeScript feature that allows us to type `get` as `(() => T) & WhenSync<() => undefined>`, which of course is extremely far-fetched.
So we have two problems: lack of inference and unsoundness. Lack of inference can be solved if TypeScript can improves its inference for invariants. And unsoundness can be solved if TypeScript introduces something like `WhenSync`. To work around lack of inference we manually annotate the state type. And we can't work around unsoundness, but it's not a big deal because it's not much, calling `get` synchronously anyway doesn't make sense.
So we have two problems: lack of inference and unsoundness. Lack of inference can be solved if TypeScript can improve its inference for invariants. And unsoundness can be solved if TypeScript introduces something like `WhenSync`. To work around lack of inference we manually annotate the state type. And we can't work around unsoundness, but it's not a big deal because it's not much, calling `get` synchronously anyway doesn't make sense.
</details>