Update method from withReference document should be same as set method

[happyharis]

Currently, the document from the withReference collection can set with the object:

class Movie {
  Movie({required this.title, required this.genre});

  Movie.fromJson(Map<String, Object?> json)
    : this(
        title: json['title']! as String,
        genre: json['genre']! as String,
      );

  final String title;
  final String genre;

  Map<String, Object?> toJson() {
    return {
      'title': title,
      'genre': genre,
    };
  }
}

final moviesRef = FirebaseFirestore.instance.collection('movies').withConverter(
      fromFirestore: (snapshot, _) => Movie.fromJson(snapshot.data()!),
      toFirestore: (movie, _) => movie.toJson(),
    );
final id = '1';
final movie =  Movie(title: 'Star Wars: A New Hope (Episode IV)', genre: 'Sci-fi');

await moviesRef.doc(id).set(movie);

However, when updating the doc, it requires a Map<String, dynamic>:

await moviesRef.doc(id).update(movie.toJson());

I expected it to pass an object instead:

await moviesRef.doc(id).update(movie);

What is the reason for the different implementation for set and update?

[rrousselGit]

update is for partial object update. More specifically, with update, we may want just change the title:

moviesRef.doc(id).update({ 'title': 'New title' });

This is not feasible if update receives a class as a parameter. If it did, that would make update identical to set.

[happyharis]

That is true since set is for whole object update/create while update is for partial updates, right?

[rrousselGit]

Indeed

But maybe in the future, Dart will have structural types and support partial objects. At which points, update would be updated to match