mixin constructor wrongly typed

TypeScript Version: 3.9.2

Search Terms: mixin constructor signature

Code

class A
{
    constructor(public x:number){}
}

function f<T extends { new(...args: any[]): object }>(cls:T) {
    return class DynamicProxy extends cls {
        constructor(...args: any[]) {
            super(1);
        }
    }
}

const B = f(A);
var b = new B();
b.x;

Expected behavior: Either make it a warning or just allow any constructor signature.

Actual behavior: Errors with Expected 1 arguments, but got 0.(2554)

Playground Link: https://www.typescriptlang.org/play/index.html?ssl=1&ssc=1&pln=16&pc=5#code/MYGwhgzhAECCBQBve1XWAewHYQC4CcBXYXDfACgAdCAjEAS2GgA8AuLQgWxoFN8BKRAF94I+ADNCWEvWzRxAHgAq0Hs1w8sAExiJoWHgHdyAOjNh8AcwitoYLAE8A2gF1+tjDQBWPEtCEAfOSgNkr80Mho0Pg8uIT4WOjgUNAAIg5YYJyMAAr4GMwOquqaOkm6KFFomDgExKQUZiYW1rb2zm4RlVVVEISUfOQAjPwA3N1VIlEiYjV40ABC0AC88uSwY-AAbhbQNCv6RovkmzQmzKNAA

Related Issues:

Start by reproducing the constructor-signature error in the linked TypeScript Playground using the provided TypeScript 3.9.2 example. Trace the compiler's checking of the mixin constructor and verify that constructing B without arguments is either accepted or produces only a warning, as requested.