__TS__DescriptorGet uses rawget, which ignores __index, therefore returning nil when trying to access fields or methods of base class

For example, in dota_ts_adapter:

setmetatable(BaseAbility.prototype, {
  __index: CDOTA_Ability_Lua ?? C_DOTA_Ability_Lua,
});

Then, extending BaseAbility and calling method on super

class SuperAbility extends BaseAbility {
    GetBehavior() {
        const res = super.GetBehavior();
        // ...
    }
}

Produces the following lua code:

local res = __TS__DescriptorGet(self, BaseAbility.prototype, "GetBehavior")(self)

Which causes attempt to call a nil value error in runtime