Function get_own_property_descriptor_str 

pub fn get_own_property_descriptor_str<T>(
    target: &Object<T>,
    property_key: &JsString,
) -> Result<PropertyDescriptor<T>, JsValue>
where
    Object<T>: ErasableGenericBorrow<Object<JsValue>>,
    PropertyDescriptor<T>: ErasableGenericOwn<PropertyDescriptor<JsValue>>,

The static Reflect.getOwnPropertyDescriptor() method is similar to Object.getOwnPropertyDescriptor(). It returns a property descriptor of the given property if it exists on the object, undefined otherwise.

MDN documentation