JSX with generics loses type inference on children if its a callback #2802
Description
Steps to reproduce
import React from 'react';
declare const TestComponentWithChildren: <T, TParam>(props: {
state: T;
selector?: (state: NoInfer<T>) => TParam;
children?: (state: NoInfer<TParam>) => React.ReactNode | undefined;
}) => React.ReactNode;
declare const TestComponentWithoutChildren: <T, TParam>(props: {
state: T;
selector?: (state: NoInfer<T>) => TParam;
notChildren?: (state: NoInfer<TParam>) => React.ReactNode | undefined;
}) => React.ReactNode;
const App = () => {
return (
<>
<TestComponentWithChildren state={{ foo: 123 }} selector={(state) => state.foo}>
{(selected) => <div>{Math.max(selected, 0)}</div>}
</TestComponentWithChildren>
<TestComponentWithoutChildren
state={{ foo: 123 }}
selector={(state) => state.foo}
notChildren={(selected) => <div>{Math.max(selected, 0)}</div>}
/>
</>
);
};Behavior with typescript@6.0
selected is inferred as a number in TestComponentWithChildren and type-checking succeeds
Behavior with tsgo
selected is resolved as unknown in TestComponentWithChildren and this code fails type-checking.
src/index.tsx:19:39 - error TS2345: Argument of type 'unknown' is not assignable to parameter of type 'number'.
19 {(selected) => <div>{Math.max(selected, 0)}</div>}
~~~~~~~~
Interestingly, this happens only with children in TestComponentWithChildren but not in notChildren in TestComponentWithoutChildren
Version Information
This behavior was introduced in 7.0.0-dev.20260213.1, this problem does not occur in 7.0.0-dev.20260212.1