Query.where adding isNotEqualTo from 4.13.1 to 4.13.6

[andy-tmpt-me]

Hi all! Enjoying building with Flutter and Firebase. Filing this as Q&A because its possibly an error on my part.

My Flutter web application broke when I updated the cloud_firestore package from 4.13.1 to 4.13.6

The issue appeared when I tried to wrap the Query.where method as follows:

class QueryWrapper<T> {
 final List<Object> fields = [];
  Query<Map<String, dynamic>> query;
...

QueryWrapper<T> where(
    Object field, {
    Object? isEqualTo,
    Object? isNotEqualTo,
    Object? isLessThan,
    Object? isLessThanOrEqualTo,
    Object? isGreaterThan,
    Object? isGreaterThanOrEqualTo,
    Object? arrayContains,
    Iterable<Object?>? arrayContainsAny,
    Iterable<Object?>? whereIn,
    Iterable<Object?>? whereNotIn,
    bool? isNull,
  }) {
    fields.add(field);
    query = query.where(field,
        isEqualTo: isEqualTo,
        isNotEqualTo: isNotEqualTo,
        isLessThan: isLessThan,
        isLessThanOrEqualTo: isLessThanOrEqualTo,
        isGreaterThan: isGreaterThan,
        isGreaterThanOrEqualTo: isGreaterThanOrEqualTo,
        arrayContains: arrayContains,
        arrayContainsAny: arrayContainsAny,
        whereIn: whereIn,
        whereNotIn: whereNotIn,
        isNull: isNull);
    return this;
  }

(The intent of this wrapper class is just to record the fields being queried so I have better diagnostics for permission denied and other such errors)

What's happening with 4.13.6 is that when I call something like:

wrapper.where('community_id', isEqualTo: communityId)

The underlying query acts as if I've set both isEqualTo using my value and isNotEqualTo using null, resulting in this error:

2023-12-28T09:55:16: SEVERE: common.firebase: Error querying collection [assignments] with parameters [{where: [[FieldPath([community_id]), ==, TMPT-Service-Design], [FieldPath([community_id]), !=, null]], orderBy: []}] on field(s) [community_id]: FirebaseError: [code=permission-denied]: Missing or insufficient permissions.

Commenting out the passing of isNotEqualTo in the delegated call to Query.where fixes the issue, but I must be misunderstanding a Dart fundamental because I thought that passing null into an optional argument was semantically equivalent to not passing the argument at all.

Thanks for any pointers!