How should I get an `IJSObjectReference` when invoking a js function which may return `null`?

For example, I have a module in typescript like:

export function getIndexedDb() : IDBFactory | null{    if (window.indexedDB)        return window.indexedDB;    else        return null;}

Now I want to get an IJSObjectReference of its result, so I have tried this in csharp:

await using var module = await jsRuntime.InvokeAsync<IJSObjectReference>("import", "xxxx.js");await using var result = await module.InvokeAsync<IJSObjectReference>("getIndexedDb");

It works well when there is a window.indexedDB, but when getIndexedDb() returns null, an error will occur:

Uncaught (in promise) Error: Cannot create a JSObjectReference from the value 'null'.

(And I can't even catch the exception in C#. The C# method seems to just stopped here and later codes won't be executed. Is this a bug?)

So what should I do to solve this problem? I don't believe the below one is a good idea:

class Nullable<T>{    value: T | null;    constructor(value: T | null)    {        this.value = value;    }    getValue() : T | null    {        return this.value;    }    isNull() : boolean    {        return this.value === null;    }}export function getIndexedDb() : Nullable<IDBFactory>{    if (window.indexedDB)        return new Nullable<IDBFactory>(window.indexedDB);    else        return new Nullable<IDBFactory>(null);}