fix: remove null from != and not-in filters' result

Author: milaGGL

firebase-firestore/src/androidTest/java/com/google/firebase/firestore/QueryTest.java

@@ -1630,4 +1630,56 @@ public void testOrderByEquality() {
     Query query2 = collection.where(inArray("a", asList(2, 3))).orderBy("a");
     checkOnlineAndOfflineResultsMatch(query2, "doc6", "doc3");
   }
+
+  @Test
+  public void testSDKUsesNotEqualFiltersSameAsServer() {
+    Map<String, Map<String, Object>> testDocs =
+        map(
+            "a", map("zip", Double.NaN),
+            "b", map("zip", 91102L),
+            "c", map("zip", 98101L),
+            "d", map("zip", "98101"),
+            "e", map("zip", asList(98101L)),
+            "f", map("zip", asList(98101L, 98102L)),
+            "g", map("zip", asList("98101", map("zip", 98101L))),
+            "h", map("zip", map("code", 500L)),
+            "i", map("zip", null),
+            "j", map("code", 500L));
+    CollectionReference collection = testCollectionWithDocs(testDocs);
+
+    // populate cache with all documents first to ensure getDocsFromCache() scans all docs
+    waitFor(testCollectionWithDocs(testDocs).get());
+
+    Query query = collection.whereNotEqualTo("zip", 98101L);
+    checkOnlineAndOfflineResultsMatch(query, "a", "b", "d", "e", "f", "g", "h");
+
+    query = collection.whereNotEqualTo("zip", Double.NaN);
+    checkOnlineAndOfflineResultsMatch(query, "b", "c", "d", "e", "f", "g", "h");
+  }
+
+  @Test
+  public void testSDKUsesNotInFiltersSameAsServer() {
+    Map<String, Map<String, Object>> testDocs =
+        map(
+            "a", map("zip", Double.NaN),
+            "b", map("zip", 91102L),
+            "c", map("zip", 98101L),
+            "d", map("zip", "98101"),
+            "e", map("zip", asList(98101L)),
+            "f", map("zip", asList(98101L, 98102L)),
+            "g", map("zip", asList("98101", map("zip", 98101L))),
+            "h", map("zip", map("code", 500L)),
+            "i", map("zip", null),
+            "j", map("code", 500L));
+    CollectionReference collection = testCollectionWithDocs(testDocs);
+
+    // populate cache with all documents first to ensure getDocsFromCache() scans all docs
+    waitFor(testCollectionWithDocs(testDocs).get());
+
+    Query query = collection.whereNotIn("zip", asList(98101L, 98103L, asList(98101L, 98102L)));
+    checkOnlineAndOfflineResultsMatch(query, "a", "b", "d", "e", "g", "h");
+
+    query = collection.whereNotIn("zip", nullList());
+    checkOnlineAndOfflineResultsMatch(query);
+  }
 }

firebase-firestore/src/main/java/com/google/firebase/firestore/core/FieldFilter.java

@@ -115,7 +115,9 @@ public boolean matches(Document doc) {
     Value other = doc.getField(field);
     // Types do not have to match in NOT_EQUAL filters.
     if (operator == Operator.NOT_EQUAL) {
-      return other != null && this.matchesComparison(Values.compare(other, value));
+      return other != null
+          && !other.hasNullValue()
+          && this.matchesComparison(Values.compare(other, value));
     }
     // Only compare types with matching backend order (such as double and int).
     return other != null

firebase-firestore/src/main/java/com/google/firebase/firestore/core/NotInFilter.java

@@ -34,6 +34,8 @@ public boolean matches(Document doc) {
       return false;
     }
     Value other = doc.getField(getField());
-    return other != null && !Values.contains(getValue().getArrayValue(), other);
+    return other != null
+        && !other.hasNullValue()
+        && !Values.contains(getValue().getArrayValue(), other);
   }
 }

firebase-firestore/src/test/java/com/google/firebase/firestore/core/QueryTest.java

@@ -237,7 +237,7 @@ public void testNotInFilters() {
 
     // Null match.
     document = doc("collection/1", 0, map("zip", null));
-    assertTrue(query.matches(document));
+    assertFalse(query.matches(document));
 
     // NaN match.
     document = doc("collection/1", 0, map("zip", Double.NaN));
@@ -333,7 +333,7 @@ public void testNaNFilter() {
     assertTrue(query.matches(doc3));
     assertTrue(query.matches(doc4));
     assertTrue(query.matches(doc5));
-    assertTrue(query.matches(doc6));
+    assertFalse(query.matches(doc6));
   }
 
   @Test