Bug Report

I'm trying to write a function that takes a (generic) constructor and calls it to instantiate a class. The type inference for such a function normally works fine, but if the constructor is for a generic class it fails even if the generic parameter has a default.

🔎 Search Terms

generic constructor parameter inference instanceof

🕗 Version & Regression Information

• This is the behavior in every version I tried, and I reviewed the FAQ for entries about constructor parameters

⏯ Playground Link

Playground link with relevant code

💻 Code

class Foo<K extends {} = {}> {}

function create<T>(type: new () => T): T {
    return new type();
}

let string = create(String); // has type String

let foo = create(Foo); // should have type Foo<{}>, has type unknown

🙁 Actual behavior

The foo variable has type unknown.

🙂 Expected behavior

I expected the foo variable to have type Foo<{}>.