Here is a basic version that demonstrates the issue. Does anyone know why I cannot pass the return value to the wrapped function? The javascript works but typescript is not allowing it.

// accept a function with unknown parameters and return a function that takes in those same paramters
const wrapFunc =
  <T extends (...args: never[]) => Promise<unknown>>(f: T): ((...args: Parameters<T>) => void) =>
  (...args: Parameters<T>) => {
    f(...args)
      .then((result) => console.log(result))
      .catch((error) => console.log(error))
  }

// a simple promise returning whatever string is given to it
const promise = async (word: string) => word

wrapFunc(promise)('works!')

// this accepts a promise that is the same type that wrapFunc does and gives the promise to wrapFunc
// it also accepts a function that returns the same type of parameter that the promise takes and passes
// the return value from the second function to the wrapped version of the first
const passThrough = <
  T extends (...args: never[]) => Promise<unknown>,
  U extends () => Parameters<T>,
>(
  f: T,
  paramsGenerator: U,
) => {
  const wrapped = wrapFunc(f)
  wrapped(paramsGenerator())
}

passThrough(promise, () => 'this works when ran but fails compilation!')

  

Output

"use strict";
// accept a function with unknown parameters and return a function that takes in those same paramters
const wrapFunc = (f) => (...args) => {
    f(...args)
        .then((result) => console.log(result))
        .catch((error) => console.log(error));
};
// a simple promise returning whatever string is given to it
const promise = async (word) => word;
wrapFunc(promise)('works!');
// this accepts a promise that is the same type that wrapFunc does and gives the promise to wrapFunc
// it also accepts a function that returns the same type of parameter that the promise takes and passes
// the return value from the second function to the wrapped version of the first
const passThrough = (f, paramsGenerator) => {
    const wrapped = wrapFunc(f);
    wrapped(paramsGenerator());
};
passThrough(promise, () => 'this works when ran but fails compilation!');

Compiler Options

{
  "compilerOptions": {
    "strict": true,
    "noImplicitAny": true,
    "strictNullChecks": true,
    "strictFunctionTypes": true,
    "strictPropertyInitialization": true,
    "strictBindCallApply": true,
    "noImplicitThis": true,
    "noImplicitReturns": true,
    "alwaysStrict": true,
    "esModuleInterop": true,
    "declaration": true,
    "target": "ES2017",
    "jsx": "react",
    "module": "ESNext",
    "moduleResolution": "node"
  }
}

Playground Link: Provided

I tried changing the types around and even attempted not using a variadic argument and cannot get typescript to compile