Type '[] | [undefined]' is not assignable to type '[] | [string]'

[Bubblesphere]

Hi, I'm getting the following error

Argument of type '() => Generator<string, void, string>' is not assignable to parameter of type '(setCancelHandler: (onCancel?: (() => void) | undefined, onCancelError?: ((err: Error) => void) | undefined) => void) => IterableIterator<any>'.
  Type 'Generator<string, void, string>' is not assignable to type 'IterableIterator<any>'.
    Types of property 'next' are incompatible.
      Type '(...args: [] | [string]) => IteratorResult<string, void>' is not assignable to type '(...args: [] | [undefined]) => IteratorResult<any, any>'.
        Types of parameters 'args' and 'args' are incompatible.
          Type '[] | [undefined]' is not assignable to type '[] | [string]'.
            Type '[undefined]' is not assignable to type '[] | [string]'.
              Type '[undefined]' is not assignable to type '[string]'.
                Type 'undefined' is not assignable to type 'string'.ts(2345)

using

const [a, setA] = useState('');
useAsyncEffect(function*() {
    const value: string = yield "foobars";
    setA(value);
}, []);

which seems to be caused by
result = generator.next(result.value);

because TNext is undefined by default
Iterator<T, TReturn = any, TNext = undefined>

[n1ru4l]

@Bubblesphere Does changing the following line:

use-async-effect/src/use-async-effect.ts

Line 12 in 89295c7

IterableIterator<any>,

to Iterator<any, any> resolve this issue?

[dawsonc623]

I ran into this issue. I changed IterableIterator<any> to Iterator<any, any, any> in the typings to make the error go away. I am not entirely sure what the ramifications of the change may be, though.

[n1ru4l]

@dawsonc623 That should be fine, could you please send a pull request for this?

[dawsonc623]

@n1ru4l Done 👍

[n1ru4l]

🎉 This issue has been resolved in version 1.1.7 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot 📦🚀