Static method on abstract class with generic this parameter causes "excessively deep" error when called on concrete class

🔎 Search Terms

• abstract class
• static method
• this parameter
• excessively deep
• concrete class
• generic

🕗 Version & Regression Information

This is broken in 5.6, 5.7, and nightly at least.

⏯ Playground Link

https://www.typescriptlang.org/play/?target=99&ts=5.8.0-dev.20250117&ssl=6&ssc=12&pln=6&pc=15#code/IYIwzgLgTsDGEAJYBthjAgguacIGFV0AeAEQD4EBvAKAXoQHMBTRAE2AmAAoBKALgSlqdBmKisArlAB21AL4I0CSTIDWMgPYB3OctKj68moYSROAS1gIAHgE8AXsQAqCZjYjMZbDBDsAHZk0AMywcGHhCNDBiYBk7cnJuUzEIAAsLMEFnABoUhg4ubLcPLx8EP0CQsMgIgiIYixlg5ighSgB+IQRBGWYAN1bTXgUaYxoUaIR8TRlYCU8o9BLPbwxsWrwlmNqmxkpaMZMZuYXmbYA6ewduAEYAJgBmXiA

💻 Code

abstract class AbstractClass<D> {
    get data(): D {
        return {} as unknown as D
    }

    static xyz<T extends typeof AbstractClass<any>>(
        this: T,
        data: T extends typeof AbstractClass<infer D> ? D : never
    ) {}
}

class ConcreteClass extends AbstractClass<string> {

}

ConcreteClass.xyz(123)

🙁 Actual behavior

The ConcreteClass.xyz results in Type instantiation is excessively deep and possibly infinite. and as a result infers D as never.

🙂 Expected behavior

This to work fine. A similar case, but where InstanceType<T> extends AbstractClass<infer D> ? D : never works fine: https://www.typescriptlang.org/play/?target=99&ts=5.8.0-dev.20250117#code/IYIwzgLgTsDGEAJYBthjAgguacIGFV0AeAEQD4EBvAKAXoQHMBTRAE2AmAAoBKALgSlqdBmKisArlAB21AL4I0CSTIDWMgPYB3OctKj68moYSROAS1gIAHgE8AXsQAqCZjYjMZbDBDsAHZk0AMywcGHhCNDBiYBk7cnJuUzEIAAsLMEFnABoUhg4uQQBJGXMZWGZnAOYXSndPbwxsSAiCIhiLGWDmKCFKAH4hBEEZZgA3XtNeBRpjGhRohHxNColPKPQ3Dy8fMNa8TZjWrsZKWjmTFbXWZiOAOnsHbgBGACYAZl4gA

Additional information about the issue

No response

Bắt đầu bằng cách chạy bản tái hiện TypeScript Playground được cung cấp và so sánh nó với biến thể InstanceType đang hoạt động. Theo dõi cách trình biên dịch xử lý tham số this tĩnh và việc suy luận kiểu có điều kiện; hoàn thành khi ConcreteClass.xyz không còn báo lỗi khởi tạo quá sâu và suy luận được kiểu mong muốn.