Add support for float/long to double/decimal conversion (fixes graphql-dotnet#840) (graphql-dotnet#893)

Author: huysentruitw

src/GraphQL.Tests/ValueConverterFacts.cs

@@ -7,6 +7,37 @@ namespace GraphQL.Tests
 {
     public class ValueConverterFacts
     {
+        [Theory]
+        [InlineData(1234L, 1234.0)]
+        public void LongConversions(long source, object expected)
+        {
+            var actual = ValueConverter.ConvertTo(source, expected.GetType());
+
+            actual.ShouldBeOfType(expected.GetType());
+            actual.ShouldBe(expected);
+        }
+
+        [Theory]
+        [InlineData(12.5f, 12.5)]
+        public void FloatConversions(float source, object expected)
+        {
+            var actual = ValueConverter.ConvertTo(source, expected.GetType());
+
+            actual.ShouldBeOfType(expected.GetType());
+            actual.ShouldBe(expected);
+        }
+
+        [Theory]
+        [InlineData(1234L, 1234.0)]
+        [InlineData(12.5f, 12.5)]
+        public void ToDecimalConversions(object source, object expected)
+        {
+            var actual = ValueConverter.ConvertTo(source, typeof(decimal));
+
+            actual.ShouldBeOfType(typeof(decimal));
+            actual.ShouldBe(new decimal((double)expected));
+        }
+
         [Theory]
         [InlineData("100", "100")]
         [InlineData("100", 100)]

src/GraphQL/ValueConverter.cs

@@ -45,8 +45,13 @@ static ValueConverter()
             Register(typeof(long), typeof(int), LongToInt);
             Register(typeof(long), typeof(uint), LongToUInt);
             Register(typeof(long), typeof(ulong), LongToULong);
+            Register(typeof(long), typeof(double), LongToDouble);
+            Register(typeof(long), typeof(decimal), LongToDecimal);
             Register(typeof(long), typeof(TimeSpan), LongToTimeSpan);
 
+            Register(typeof(float), typeof(double), FloatToDouble);
+            Register(typeof(float), typeof(decimal), FloatToDecimal);
+
             Register(typeof(double), typeof(decimal), DoubleToDecimal);
 
             Register(typeof(string), typeof(Uri), ParseUri);
@@ -64,12 +69,36 @@ private static object IntToDecimal(object value)
             return Convert.ToDecimal(intValue, NumberFormatInfo.InvariantInfo);
         }
 
+        private static object FloatToDouble(object value)
+        {
+            var floatValue = (float)value;
+            return (double)floatValue;
+        }
+
+        private static object FloatToDecimal(object value)
+        {
+            var floatValue = (float)value;
+            return Convert.ToDecimal(floatValue, NumberFormatInfo.InvariantInfo);
+        }
+
         private static object DoubleToDecimal(object value)
         {
             var doubleValue = (double)value;
             return Convert.ToDecimal(doubleValue, NumberFormatInfo.InvariantInfo);
         }
 
+        private static object LongToDouble(object value)
+        {
+            var longValue = (long)value;
+            return (double)longValue;
+        }
+
+        private static object LongToDecimal(object value)
+        {
+            var longValue = (long)value;
+            return (decimal)longValue;
+        }
+
         private static object LongToInt(object value)
         {
             var longValue = (long)value;
@@ -210,8 +239,6 @@ private static object convertToUInt32<T>(T value) =>
         private static object convertToUInt64<T>(T value) =>
             Convert.ToUInt64(value, NumberFormatInfo.InvariantInfo);
 
-
-
         public static object ConvertTo(object value, Type targetType)
         {
             if (value == null)