getUserById method
Implementation
Future<mm.User?> getUserById(String id) async {
final doc = await getFirebaseFirestore
.collection(FireChatConst.usersCollectionName)
.doc(id)
.get();
if (!doc.exists) return null;
final data = doc.data();
if (data == null) return null;
data['id'] = doc.id;
data['createdAt'] = data['createdAt']?.millisecondsSinceEpoch;
data['lastSeen'] = data['lastSeen']?.millisecondsSinceEpoch;
data['updatedAt'] = data['updatedAt']?.millisecondsSinceEpoch;
return mm.User.fromJson(data);
}