TS Error with datetimeFormats - no support using custom schemas?

[felixzapata]

Following the Type-safe resources with schema section example in the TypeScript support area, I'm trying to use also a custom schema for the datetimeFormats.

const i18n = createI18n<
  {
    message: MessageSchema;
    number: NumberSchema;
    datetime: DateSchema;
  },
  "en-US" | "es-ES",
  false
>({
...
numberFormats: {
....
}
datetimeFormats: {
...
}
...
});

The schema for the dates:

export type NumberSchema = {
  ......
};
export type DateSchema = {
  long: {
    year: "numeric";
    month: "short";
    day: "numeric";
    weekday: "short";
    hour: "numeric";
    minute: "numeric";
    hour12: boolean;
  };
  short: {
    year?: "string";
    month?: "short";
    day?: "string";
    hour: "numeric";
    minute: "numeric";
    second: "numeric";
    timeZoneName: "short";
    timezone: string;
  };
};

But when I put incorrectly a property name in the datetimeFormats object, the TypeScript checker refers to a core file instead of my scheme file.

If a set an incorrect property for the numberFormats object, the checker refers to my scheme file.

Am I doing something wrong? Is this a bug?