check fuzzy nullability

Author: WaVEV

django_mongodb_backend/expressions/search.py

@@ -544,7 +544,7 @@ def search_operator(self, compiler, connection):
         }
         if self.score:
             params["score"] = self.score.as_mql(compiler, connection)
-        if self.fuzzy:
+        if self.fuzzy is not None:
             params["fuzzy"] = self.fuzzy.value
         if self.match_criteria:
             params["matchCriteria"] = self.match_criteria.value
@@ -719,7 +719,7 @@ class SearchMoreLikeThis(SearchExpression):
     Reference: https://www.mongodb.com/docs/atlas/atlas-search/morelikethis/
     """
 
-    def __init__(self, documents, score=None):
+    def __init__(self, documents, *, score=None):
         self.documents = cast_as_value(documents)
         self.score = score
         super().__init__()