Behavior difference: (jsdoc) comment emit inconsistencies on expando functions

Summary as below. Note that the commit emit fix for arrows will be a breaking change from TS 6.

Steps to reproduce

1. Start a plain new project
   • "@typescript/native-preview": "7.0.0-dev.20260612.1",
   • "typescript": "6.0.3"
2. Run npx tsgo --init to get the default tsconfig. Turn on these flags as well.
   • "allowJs": true,
   • "checkJs": true,
   • "stableTypeOrdering": true,
   • "removeComments": false,
3. Add the below files. Run npx tsc & npx tsgo to see the difference.
   • Emitted type output from using .js and .ts are a bit different as shown above.

src/main.js

/**
 * jsdoc description on `ExpandoFunctionInlineNamedExport`
 */
export function ExpandoFunctionInlineNamedExport() { return null; }
ExpandoFunctionInlineNamedExport.args = { num: 3 };

/**
 * jsdoc description on `ExpandoArrowInlineNamedExport`
 */
export const ExpandoArrowInlineNamedExport = () => { return null; };
ExpandoArrowInlineNamedExport.args = { num: 3 };

/**
 * jsdoc description on `ExpandoFunctionNamedExport`
 */
function ExpandoFunctionNamedExport() { return null; }
ExpandoFunctionNamedExport.args = { num: 3 };

/**
 * jsdoc description on `ExpandoArrowNamedExport`
 */
const ExpandoArrowNamedExport = () => { return null; };
ExpandoArrowNamedExport.args = { num: 3 };

export { ExpandoFunctionNamedExport, ExpandoArrowNamedExport };

src/ExpandoFunctionDefaultExport.js

/**
 * jsdoc description on `ExpandoFunctionDefaultExport`
 */
function ExpandoFunctionDefaultExport() { return null; }
ExpandoFunctionDefaultExport.args = { num: 3 };

export default ExpandoFunctionDefaultExport;

src/ExpandoArrowDefaultExport.js

/**
 * jsdoc description on `ExpandoArrowDefaultExport`
 */
const ExpandoArrowDefaultExport = () => { return null; };
ExpandoArrowDefaultExport.args = { num: 3 };

export default ExpandoArrowDefaultExport;

Behavior with typescript@6.0

Output from using .js.

/**
 * jsdoc description on `ExpandoFunctionInlineNamedExport`
 */
export function ExpandoFunctionInlineNamedExport(): null;
export namespace ExpandoFunctionInlineNamedExport {
    namespace args {
        let num: number;
    }
}
export function ExpandoArrowInlineNamedExport(): null;
export namespace ExpandoArrowInlineNamedExport {
    export namespace args_1 {
        let num_1: number;
        export { num_1 as num };
    }
    export { args_1 as args };
}
/**
 * jsdoc description on `ExpandoFunctionNamedExport`
 */
export function ExpandoFunctionNamedExport(): null;
export namespace ExpandoFunctionNamedExport {
    export namespace args_2 {
        let num_2: number;
        export { num_2 as num };
    }
    export { args_2 as args };
}
/**
 * jsdoc description on `ExpandoArrowNamedExport`
 */
export function ExpandoArrowNamedExport(): null;
export namespace ExpandoArrowNamedExport {
    export namespace args_3 {
        let num_3: number;
        export { num_3 as num };
    }
    export { args_3 as args };
}
//# sourceMappingURL=main.d.ts.map

export default ExpandoFunctionDefaultExport;
/**
 * jsdoc description on `ExpandoFunctionDefaultExport`
 */
declare function ExpandoFunctionDefaultExport(): null;
declare namespace ExpandoFunctionDefaultExport {
    namespace args {
        let num: number;
    }
}
//# sourceMappingURL=ExpandoFunctionDefaultExport.d.ts.map

export default ExpandoArrowDefaultExport;
/**
 * jsdoc description on `ExpandoArrowDefaultExport`
 */
declare function ExpandoArrowDefaultExport(): null;
declare namespace ExpandoArrowDefaultExport {
    namespace args {
        let num: number;
    }
}
//# sourceMappingURL=ExpandoArrowDefaultExport.d.ts.map

Behavior with tsgo

Output from using .js.

/**
 * jsdoc description on `ExpandoFunctionInlineNamedExport`
 */
export declare function ExpandoFunctionInlineNamedExport(): null;
export declare namespace ExpandoFunctionInlineNamedExport {
    var args: {
        num: number;
    };
}
export declare function ExpandoArrowInlineNamedExport(): null;
export declare namespace ExpandoArrowInlineNamedExport {
    var args: {
        num: number;
    };
}
/**
 * jsdoc description on `ExpandoFunctionNamedExport`
 */
declare function ExpandoFunctionNamedExport(): null;
declare namespace ExpandoFunctionNamedExport {
    var args: {
        num: number;
    };
}
declare function ExpandoArrowNamedExport(): null;
declare namespace ExpandoArrowNamedExport {
    var args: {
        num: number;
    };
}
export { ExpandoFunctionNamedExport, ExpandoArrowNamedExport };
//# sourceMappingURL=main.d.ts.map

/**
 * jsdoc description on `ExpandoFunctionDefaultExport`
 */
declare function ExpandoFunctionDefaultExport(): null;
declare namespace ExpandoFunctionDefaultExport {
    var args: {
        num: number;
    };
}
export default ExpandoFunctionDefaultExport;
//# sourceMappingURL=ExpandoFunctionDefaultExport.d.ts.map

declare function ExpandoArrowDefaultExport(): null;
declare namespace ExpandoArrowDefaultExport {
    var args: {
        num: number;
    };
}
export default ExpandoArrowDefaultExport;
//# sourceMappingURL=ExpandoArrowDefaultExport.d.ts.map

Empieza con los cuatro archivos fuente de src/ y reproduce la salida de declaraciones usando tsc y tsgo con allowJs, checkJs, stableTypeOrdering y removeComments deshabilitados. Compara la emisión de JSDoc para las exportaciones expando de function y arrow entre exportaciones con nombre y default; se considera terminado cuando las salidas siguen un comportamiento coherente y acordado.