Cannot select object type from wrapping object using parameter

[wbt]

Bug Report

🔎 Search Terms

Deferred parameter select generic index

🕗 Version & Regression Information

• This is the behavior in every version I tried, and I reviewed the FAQ for entries about type parameters
• Nightly version at time of test: v5.0.0-dev.20230123

⏯ Playground Link

Playground link with relevant code

💻 Code

type DataFetchFns = {
    Boat: {
        requiresLicense: (id: string) => boolean;
        maxGroundSpeed: (id: string) => number;
        description: (id: string) => string;
        displacement: (id: string) => number;
        name: (id: string) => string;
    };
    Plane: {
        requiresLicense: (id: string) => boolean;
        maxGroundSpeed: (id: string) => number;
        maxTakeoffWeight: (id: string) => number;
        maxCruisingAltitude: (id: string) => number;
        name: (id: string) => string;
    }
}
//Can select non-object type from wrapping object using parameter:
export type NoTypeParamBoatRequired<F extends keyof DataFetchFns['Boat']> = ReturnType<DataFetchFns['Boat'][F]>;
type TypeHardcodedAsParameterWithoutReturnType<T extends 'Boat', F extends keyof DataFetchFns[T]> = DataFetchFns[T][F];
export type allAreFunctionsAsExpected = TypeHardcodedAsParameterWithoutReturnType<'Boat', keyof DataFetchFns['Boat']>;
// Above line is as expected: ((id: string) => boolean) | ((id: string) => number) |
// ((id: string) => string) | ((id: string) => number) | ((id: string) => string)
export type returnTypeOfFunctions = ReturnType<allAreFunctionsAsExpected>; //string | number | boolean as expected
export type SucceedingCombo = ReturnType<TypeHardcodedAsParameterWithoutReturnType<'Boat', keyof DataFetchFns['Boat']>>;
//Now try putting those definitions of TypeHardcodedAsParameterWithoutReturnType & returnTypeOfFunctions together: it fails.
//Why should the below fail while the line above succeeds? Error given is
//Type 'DataFetchFns[T][F]' does not satisfy the constraint '(...args: any) => any'.
export type FailingCombo<T extends 'Boat', F extends keyof DataFetchFns[T]> = ReturnType<TypeHardcodedAsParameterWithoutReturnType<T,F>>;
export type TypeHardcodedAsParameter<T extends 'Boat', F extends keyof DataFetchFns[T]> = ReturnType<DataFetchFns[T][F]>;
type VehicleSelector<T extends keyof DataFetchFns> = DataFetchFns[T]; //workaround attempt that doesn't work
export type TypeHardcodedAsParameter2<T extends 'Boat', F extends keyof DataFetchFns[T]> = ReturnType<VehicleSelector<T>[F]>;
//Eventual goal:
export type TypeGeneric<T extends keyof DataFetchFns, F extends keyof DataFetchFns[T]> = ReturnType<DataFetchFns[T][F]>;

🙁 Actual behavior

Errors as shown, TypeScript can't figure out that the contents of ReturnType<> are function types, when a generic type parameter from the left side of a type definition is used in the right side, though it can in the definition of allAreFunctionsAsExpected.

🙂 Expected behavior

No errors in this example. All of the type definitions throwing errors should simplify to string | number | boolean in this toy example.

[islandryu]

I'll work on it.