NgRx 数据服务更新删除 object 原型，而不是更新更改的字段

Question

When my NgRx DefaultDataService updates, it removes the type/prototype of the objects in the store. The objects are no longer of type Todo, but are simple objects with no prototype.

The objects come from the server as json objects conforming to the Todo interface . I pipe them to be entered into the store as Todo objects like this:

@Injectable()
export class TodosDataService extends DefaultDataService<ITodo> {
    baseUrl;

constructor( http: HttpClient, httpUrlGenerator: HttpUrlGenerator) {
    super("Todos", http, httpUrlGenerator);
}

getAll(): Observable<Todo[]> {

    //HERE - the ITodo[] from server is mapped to Todo[], then saved to store
    return super.getAll().pipe(
        map(todosList => todosList.map(todoData => new Todo(todoData)))
    );
}

But piping them on this service's update() override method doesn't work:

update(updatedTodo: Update<Todo>): Observable<Todo> {
    return super.update(updatedTodo).pipe(map(data => new Todo(data)));
}

Note: I've also tried this using my own httpClient.put request manually without DefaultDataService's super call and several other ways.

The problem problem is that when ngrx applies the deltas (changes) to the object in the store, it somehow not a todo object anymore . Here's a screenshot of the console right after running the above statement:

Todo Prototype is gone

This is causing unexpected behavior.

TL;DR: How can we make sure the update does not remove the prototype? If that's not possible, is there a simple way to intercept updates before they hit the store, in order to provide custom implementation?

Answer 1

This behavior is intended see the following GitHub issue for more info. https://github.com/ngrx/platform/issues/1641