(#604) Fix for negative search comparison in offline table.

sdk/dotnet/src/Microsoft.Datasync.Client/Query/OData/ODataExpressionParser.cs

@@ -219,7 +219,7 @@ private QueryNode ParseUnary()
                 {
                     lexer.Token.Text = $"-{lexer.Token.Text}";
                     lexer.Token.Position = operatorPosition;
-                    ParsePrimary();
+                    return ParsePrimary();
                 }
 
                 QueryNode expression = ParseUnary();

sdk/dotnet/test/Datasync.Common.Test/Models/KitchenSink.cs

@@ -24,6 +24,7 @@ public class KitchenSink : EntityTableData
         public decimal DecimalValue { get; set; }
         public double DoubleValue { get; set; }
         public float FloatValue { get; set; }
+        public double? NullableDouble { get; set; }
 
         // String
         public char CharValue { get; set; }

sdk/dotnet/test/Microsoft.Datasync.Client.Test/Query/ODataExpressionParser.Test.cs

@@ -347,6 +347,7 @@ public void QueryTokenKind_ToBinaryOperatorKind_ThrowsOnInvalid(QueryTokenKind k
 		[InlineData("$filter=(not(bestPictureWinner) and (ceiling((duration div 60.0)) eq 2.0))")]
 		[InlineData("$filter=(not(bestPictureWinner) and (floor((duration div 60.0)) eq 2.0))")]
 		[InlineData("$filter=(year lt 1990.5f)")]
+        [InlineData("$filter=(nullableValue le -0.5)")]
         public void ODataExpressionParser_Roundtrips(string original)
         {
             var query = QueryDescription.Parse("movies", original);

sdk/dotnet/test/Microsoft.Datasync.Client.Test/Query/TableQuery.Test.cs

@@ -764,12 +764,39 @@ public void ToODataString_DefaultIncludeParameters()
             Assert.Equal("$orderby=releaseDate&foo=bar", actual);
         }
 
+        [Fact]
+        public void ToODataString_NegativeDouble_Works()
+        {
+            var client = GetMockClient();
+            var table = new RemoteTable<KSV>("ksv", client);
+            var query = new TableQuery<KSV>(table).Where(x => x.Value <= -0.5) as TableQuery<KSV>;
+            var actual = query.ToODataString();
+            Assert.Equal("$filter=(value le -0.5)", actual);
+        }
+
+        [Fact]
+        public void ToODataString_NegativeNullableDouble_Works()
+        {
+            var client = GetMockClient();
+            var table = new RemoteTable<KSV>("ksv", client);
+            var query = new TableQuery<KSV>(table).Where(x => x.NullableValue <= -0.5) as TableQuery<KSV>;
+            var actual = query.ToODataString();
+            Assert.Equal("$filter=(nullableValue le -0.5)", actual);
+        }
+
         #region Models
         public class SelectResult
         {
             public string Id { get; set; }
             public string Title { get; set; }
         }
+
+        public class KSV : DatasyncClientData
+        {
+            public double Value { get; set; }
+
+            public double? NullableValue { get; set; }
+        }
         #endregion
     }
 }

sdk/dotnet/test/Microsoft.Datasync.Integration.Test/Helpers/Models.cs

@@ -48,6 +48,7 @@ public class KitchenSinkDto : DatasyncClientData
         public decimal DecimalValue { get; set; }
         public double DoubleValue { get; set; }
         public float FloatValue { get; set; }
+        public double? NullableDouble { get; set; }
 
         // String
         public char CharValue { get; set; }

sdk/dotnet/test/Microsoft.Datasync.Integration.Test/KitchenSink/KitchenSink.Test.cs

@@ -59,7 +59,30 @@ public async Task KS1_NullRoundtrips()
         }
 
         [Fact]
-        public async Task KS2_DeferredTableDefinition()
+        public async Task KS2_NullDoubleSearch()
+        {
+            // On client 1
+            KitchenSinkDto client1dto = new() { NullableDouble = -1.0 };
+            await remoteTable.InsertItemAsync(client1dto);
+            var remoteId = client1dto.Id;
+            Assert.NotEmpty(remoteId);
+
+            // On client 2
+            await InitializeAsync();
+            var pullQuery = offlineTable!.CreateQuery();
+            await offlineTable!.PullItemsAsync(pullQuery, new PullOptions());
+            var client2dto = await offlineTable.GetItemAsync(remoteId);
+            Assert.NotNull(client2dto);
+            Assert.True(client2dto.NullableDouble < -0.5);
+
+            // Finally, let's search!
+            var elements = await offlineTable!.Where(x => x.NullableDouble < -0.5).ToListAsync();
+            Assert.Single(elements);
+            Assert.Equal(elements[0].Id, remoteId);
+        }
+
+        [Fact]
+        public async Task KS3_DeferredTableDefinition()
         {
             var filename = Path.GetTempFileName();
             var connectionString = new UriBuilder(filename) { Query = "?mode=rwc" }.Uri.ToString();