Index signature added to classes that inherit an any typed class

[dragomirtitian]

🔎 Search Terms

index signature any

🕗 Version & Regression Information

• This changed between versions 5.7.0-dev.20240923 and 5.7.0-dev.20240924
• This probably changed in PR Support interpreting non-literal computed properties in classes as implicit index signatures #59860

⏯ Playground Link

Playground Link

💻 Code

const AnyClass = class {} as any;
export class Cls extends AnyClass { }

🙁 Actual behavior

The declaration for the class contains a static index signature:

declare const AnyClass: any;
export declare class Cls extends AnyClass {
     static [x: string]: any;
}

🙂 Expected behavior

The declaration for the class does not contain the index sigature as in TS 5.6 and before:

declare const AnyClass: any;
export declare class Cls extends AnyClass {
}

Additional information about the issue

This means this declaration file can't be emitted in isolated declarations.