Passing generic function as an argument fails compile

[endercrest]

It would seem that the compiler isn't resolving the type for a generic function that is being passed in as an argument where the type should be resolvable.

Example Code:

function freeFunction<T>(value: T): T {
  return value;
}

function bad<T>(value: T, func: (value: T) => T): T {
  return func(value);
}

export function test(): i64 {
  return bad<i64>(123, freeFunction);
}

WebAssembly Studio Example: https://webassembly.studio/?f=gpmwo8wi18h

Error:

ERROR TS2554: Expected 1 arguments, but got 0.

   return bad<i64>(123, freeFunction);
                        ~~~~~~~~~~~~
 in main.ts(10,24)

FAILURE 1 compile error(s)

[dcodeIO]

The underlying cause appears to be that a generic function is passed by value, but in AS doesn't have a value at runtime (only concrete functions have one). It looks, however, like it can be supported by handling the case specifically - need to check.

In the meantime, a workaround could be:

export function test(): i64 {
  return bad<i64>(123, v => freeFunction(v));
}