Merge pull request #58 from seesharper/fix-nullables-with-scalarvalues

Fix nullables with scalarvalues
seesharper · Sep 1, 2022 · 67c5f9d · 67c5f9d
2 parents e5889d8 + eaa8cb6
commit 67c5f9d
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Showing 4 changed files with 25 additions and 11 deletions.
diff --git a/src/DbReader.Tests/IntegrationTests.cs b/src/DbReader.Tests/IntegrationTests.cs
@@ -28,6 +28,8 @@ static IntegrationTests()
 
             DbReaderOptions.WhenPassing<CustomValueType>()
                 .Use((parameter, argument) => parameter.Value = argument.Value);
+
+            DbReaderOptions.WhenReading<CustomScalarValue>().Use((datarecord, i) => new CustomScalarValue(datarecord.GetInt64(i)));
         }
 
 
@@ -375,7 +377,6 @@ public void ShouldConvertScalarValue()
         [Fact]
         public async Task ShouldConvertScalarValueUsingValueConverter()
         {
-            DbReaderOptions.WhenReading<CustomScalarValue>().Use((datarecord, i) => new CustomScalarValue(datarecord.GetInt64(i)));
             using (var connection = CreateConnection())
             {
                 var scalar = await connection.ExecuteScalarAsync<CustomScalarValue>("SELECT COUNT(*) FROM Customers");
@@ -384,16 +385,27 @@ public async Task ShouldConvertScalarValueUsingValueConverter()
         }
 
         [Fact]
-        public async Task ShouldHandleNullScalarValueUsingValueConverter()
+        public async Task ShouldHandleReturningNullIntoNullableTypeWithValueConverter()
         {
-            DbReaderOptions.WhenReading<CustomScalarValue?>().Use((datarecord, i) => new CustomScalarValue(datarecord.GetInt64(i)));
             using (var connection = CreateConnection())
             {
                 var scalar = await connection.ExecuteScalarAsync<CustomScalarValue?>("SELECT NULL FROM Customers WHERE CustomerID = 'ALFKI'");
                 scalar.ShouldBe(null);
             }
         }
 
+        [Fact]
+        public async Task ShouldHandleReturningValueIntoNullableTypeWithValueConverter()
+        {
+            using (var connection = CreateConnection())
+            {
+                var scalar = await connection.ExecuteScalarAsync<CustomScalarValue?>("SELECT 1 FROM Customers WHERE CustomerID = 'ALFKI'");
+                scalar.Value.Value.ShouldBe(1);
+            }
+        }
+
+        //ShouldHandleReturningNullIntoNullableTypeWithValueConverter()
+
 
         [Fact]
         public async Task ShouldGetScalarValueAsync()

diff --git a/src/DbReader/DbConnectionExtensions.cs b/src/DbReader/DbConnectionExtensions.cs
@@ -242,12 +242,14 @@ private static T ReadScalarValue<T>(IDataReader reader)
         {
             if (!reader.Read() || reader.IsDBNull(0))
             {
-                return default(T);
+                return default;
             }
 
-            if (ValueConverter.CanConvert(typeof(T)))
+            var underlyingType = typeof(T).GetUnderlyingType();
+
+            if (ValueConverter.CanConvert(underlyingType))
             {
-                return ValueConverter.Convert<T>(reader, 0);
+                return (T)ValueConverter.GetConvertMethod(underlyingType).Invoke(null, new object[] { reader, 0 });
             }
 
             return ConvertFromDbValue<T>(reader.GetValue(0));

diff --git a/src/DbReader/DbReader.csproj b/src/DbReader/DbReader.csproj
@@ -2,7 +2,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <TargetFrameworks>netcoreapp3.1;netstandard2.0;net462</TargetFrameworks>
-    <Version>2.5.1</Version>
+    <Version>2.5.2</Version>
     <Authors>Bernhard Richter</Authors>
     <PackageProjectUrl>https://github.com/seesharper/DbReader</PackageProjectUrl>
     <RepositoryType>git</RepositoryType>

diff --git a/src/DbReader/ValueConverter.cs b/src/DbReader/ValueConverter.cs
@@ -27,15 +27,15 @@ namespace DbReader
     using System.Collections.Concurrent;
     using System.Data;
     using System.Reflection;
-    
+
     /// <summary>
     /// Used to register a custom conversion from a <see cref="IDataRecord"/> to an instance of a given <see cref="Type"/>.
     /// </summary>
     public static class ValueConverter
     {
         private static readonly ConcurrentDictionary<Type, Delegate> ReadDelegates =
             new ConcurrentDictionary<Type, Delegate>();
-       
+
         /// <summary>
         /// Registers a function delegate that creates a value of <typeparamref name="T"/> from an <see cref="IDataRecord"/>
         /// at the specified ordinal (column index).
@@ -46,7 +46,7 @@ public static void RegisterReadDelegate<T>(Func<IDataRecord, int, T> convertFunc
         {
             ReadDelegates.AddOrUpdate(typeof(T), type => convertFunction, (type, del) => convertFunction);
         }
-       
+
         /// <summary>
         /// Determines if the given <paramref name="type"/> can be converted.
         /// </summary>        
@@ -79,6 +79,6 @@ internal static MethodInfo GetConvertMethod(Type type)
         {
             var openGenericConvertMethod = typeof(ValueConverter).GetMethod("Convert", BindingFlags.Static | BindingFlags.Public);
             return openGenericConvertMethod.MakeGenericMethod(type);
-        }        
+        }
     }
 }