update method

Implementation

@override
Future<T> update(String id, T Function(T current) updater) async {
  final doc = store.doc(_normaliseToFullPath(id));
  final snapshot = await doc.get();

  final existingData = snapshot.data();
  if (existingData == null) {
    throw RepositoryException.notFound(id);
  }

  final current = fromFirestore(
    snapshot.reference,
    RepositoryFirestore.typeConversionFromFirebase.convert(source: existingData),
  );

  final updated = toFirestore(updater(current));
  final updatedJson = RepositoryFirestore.typeConversionToFirebase.convert(source: updated);
  final existingJson = RepositoryFirestore.typeConversionToFirebase.convert(source: existingData);

  final changedFields = <String, dynamic>{};
  for (final entry in updatedJson.entries) {
    if (existingJson[entry.key] != entry.value) {
      changedFields[entry.key] = entry.value;
    }
  }

  if (changedFields.isNotEmpty) {
    await doc.update(changedFields);
  }

  final finalSnapshot = await doc.get();
  final finalData = finalSnapshot.data();
  if (finalData == null) {
    throw RepositoryException.notFound(id);
  }

  return fromFirestore(
    finalSnapshot.reference,
    RepositoryFirestore.typeConversionFromFirebase.convert(source: finalData),
  );
}