Function argument Type-assertion does not work correctly

[manuth]

TypeScript Version: 3.6.0-dev.20190601

Search Terms:

• Function argument
• Type-Assertion
• Argument-Types
• promisify
• Function-overloads
• Overloads

Code

declare function sourceMaps(): NodeJS.ReadWriteStream;
declare function sourceMaps(path: string): NodeJS.ReadWriteStream;
declare function sourceMaps(path: string, options: object): NodeJS.ReadWriteStream;
declare function sourceMaps(options: object): NodeJS.ReadWriteStream;

declare function queue<TArgs extends any[]>(fn: (...args: TArgs) => NodeJS.ReadWriteStream, ...args: TArgs): any;

declare function altQueue(fn: () => NodeJS.ReadWriteStream): any;
declare function altQueue<TArg1>(fn: (arg1: TArg1) => NodeJS.ReadWriteStream, arg1: TArg1): any;
declare function altQueue<TArg1, TArg2>(fn: (arg1: TArg1, arg2: TArg2) => NodeJS.ReadWriteStream, arg1: TArg1, arg2: TArg2): any;

queue(sourceMaps);              // Reports an error
queue(sourceMaps, "");          // Reports an error
queue(sourceMaps, "", {});      // Reports an error
queue(sourceMaps, {});

altQueue(sourceMaps);
altQueue(sourceMaps, "");       // Reports an error
altQueue(sourceMaps, "", {});   // Reports an error
altQueue(sourceMaps, {});

Expected behavior:
TypeScript should recognize there is a function-overload which matches the TArgs- or TArg1- and TArg2-type.

Actual behavior:
TypeScript reports an error expecting the argument-types to match the last declaration of the function.

Playground Link:
Link to Playground

This issue is, for example, affecting the promisify-function of node.js' util-module:

import { promisify } from "util";

declare function test(callback: (error: Error, result: any) => any): void;
declare function test(name: string, callback: (error: Error, result: any) => any): void;
declare function test(options: { name: string, author: string }, callback: (error: Error, result: any) => any): void;

promisify(test)();
promisify(test)("");                        // Reports an error
promisify(test)({ name: "", author: "" });  // Reports an error

[jcalz]

Related to or duplicate of #30369, #29312 ?

Perhaps you mean "type inference" and not "type assertion"? Or at least I don't see any type assertion happening here. Also it seems that "overload" should be part of any search terms.

[manuth]

I'm not that sure whether this is the same issue but it sure does look a little similar, that's true

[RyanCavanaugh]

We can't yet support higher-order overload resolution, which is what all of these would require. The linked issues go into more detail