Null fixes for odata.

backend/src/Squidex.Infrastructure/Queries/OData/ConstantWithTypeVisitor.cs

@@ -39,25 +39,26 @@ namespace Squidex.Infrastructure.Queries.OData
         }
 
         public override ClrValue Visit(ConvertNode nodeIn)
-        {
-            if (nodeIn.TypeReference.Definition == BooleanType)
         {
             var value = ConstantVisitor.Visit(nodeIn.Source);
 
+            if (value == null)
+            {
+                return ClrValue.Null;
+            }
+
+            if (nodeIn.TypeReference.Definition == BooleanType)
+            {
                 return bool.Parse(value.ToString()!);
             }
 
             if (nodeIn.TypeReference.Definition == GuidType)
             {
-                var value = ConstantVisitor.Visit(nodeIn.Source);
-
                 return Guid.Parse(value.ToString()!);
             }
 
             if (nodeIn.TypeReference.Definition == DateTimeType || nodeIn.TypeReference.Definition == DateType)
             {
-                var value = ConstantVisitor.Visit(nodeIn.Source);
-
                 return ParseInstant(value);
             }
 
@@ -115,6 +116,13 @@ namespace Squidex.Infrastructure.Queries.OData
         }
 
         public override ClrValue Visit(ConstantNode nodeIn)
+        {
+            if (nodeIn.Value == null)
+            {
+                return ClrValue.Null;
+            }
+
+            if (nodeIn.TypeReference != null)
             {
                 if (nodeIn.TypeReference.Definition == DateTimeType || nodeIn.TypeReference.Definition == DateType)
                 {
@@ -155,6 +163,7 @@ namespace Squidex.Infrastructure.Queries.OData
                 {
                     return (string)nodeIn.Value;
                 }
+            }
 
             throw new NotSupportedException();
         }

backend/tests/Squidex.Infrastructure.Tests/Queries/QueryFromODataTests.cs

@@ -67,7 +67,7 @@ namespace Squidex.Infrastructure.Queries
         [InlineData("created")]
         [InlineData("createdNullable")]
         [InlineData("properties/datetime")]
-        [InlineData("properties/nested/dateime")]
+        [InlineData("properties/nested/datetime")]
         public void Should_parse_filter_when_type_is_datetime(string field)
         {
             var i = _Q($"$filter={field} eq 1988-01-19T12:00:00Z");
@@ -76,6 +76,19 @@ namespace Squidex.Infrastructure.Queries
             Assert.Equal(o, i);
         }
 
+        [Theory]
+        [InlineData("created")]
+        [InlineData("createdNullable")]
+        [InlineData("properties/datetime")]
+        [InlineData("properties/nested/datetime")]
+        public void Should_parse_filter_when_type_is_datetime_and_value_is_null(string field)
+        {
+            var i = _Q($"$filter={field} eq null");
+            var o = _C($"Filter: {field} == null");
+
+            Assert.Equal(o, i);
+        }
+
         [Fact]
         public void Should_parse_filter_when_type_is_datetime_list()
         {
@@ -129,6 +142,19 @@ namespace Squidex.Infrastructure.Queries
             Assert.Equal(o, i);
         }
 
+        [Theory]
+        [InlineData("id")]
+        [InlineData("idNullable")]
+        [InlineData("properties/uid")]
+        [InlineData("properties/nested/guid")]
+        public void Should_parse_filter_when_type_is_guid_and_value_is_null(string field)
+        {
+            var i = _Q($"$filter={field} eq null");
+            var o = _C($"Filter: {field} == null");
+
+            Assert.Equal(o, i);
+        }
+
         [Fact]
         public void Should_parse_filter_when_type_is_guid_list()
         {
@@ -182,6 +208,19 @@ namespace Squidex.Infrastructure.Queries
             Assert.Equal(o, i);
         }
 
+        [Theory]
+        [InlineData("isComicFigure")]
+        [InlineData("isComicFigureNullable")]
+        [InlineData("properties/boolean")]
+        [InlineData("properties/nested/boolean")]
+        public void Should_parse_filter_when_type_is_boolean_and_value_is_null(string field)
+        {
+            var i = _Q($"$filter={field} eq null");
+            var o = _C($"Filter: {field} == null");
+
+            Assert.Equal(o, i);
+        }
+
         [Fact]
         public void Should_parse_filter_when_type_is_boolean_list()
         {