Contextual typing breaks with partially applied type arguments

[myandrienko]

Bug Report

🔎 Search Terms

partial type argument inference, contextual typing

🕗 Version & Regression Information

• This is the behavior in every version I tried, and I reviewed the FAQ for entries about type inference

⏯ Playground Link

Playground link with relevant code

💻 Code

interface Props<TSchema, TValue> {
  getter: (values: TSchema) => TValue;
  worker: (value: TValue) => void;
}

declare function fn<TSchema, TValue>(props: Props<TSchema, TValue>): void;

function bindSchema<TSchema>() {
  return function boundFn<TValue>(props: Props<TSchema, TValue>) {
    fn(props);
  };
}

const boundFn = bindSchema<{ someValue: number }>();

boundFn({
  getter: (values) => values.someValue,
  worker: (value) => {
    // value is unknown :(
  }
});

🙁 Actual behavior

value parameter type in worker method (line 18). is not inferred. value type is unknown.

🙂 Expected behavior

value parameter type should be correctly inferred as number.

This code sample works fine, which is also surprising since the type for values parameter in getter method (line 17) is correctly inferred as { someValue: number } anyway:

boundFn({
  getter: (values: { someValue: number }) => values.someValue,
  worker: (value) => {
    // value is number 👍 
  }
});

[ilogico]

Looks like #43371

[typescript-bot]

This issue has been marked as a 'Duplicate' and has seen no recent activity. It has been automatically closed for house-keeping purposes.