Added fix and regression test for issue SevenSpikes#11

Nop.Plugin.Api.Tests/Nop.Plugin.Api.Tests.csproj

@@ -188,6 +188,7 @@
     <Compile Include="ServicesTests\Customers\CustomerApiServiceTests.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="SetUp.cs" />
+    <Compile Include="ValidatorTests\TypeValidatorTests_IsValid.cs" />
     <Compile Include="ValidatorTests\FieldsValidatorTests_GetValidFields.cs" />
   </ItemGroup>
   <ItemGroup>

Nop.Plugin.Api.Tests/ValidatorTests/TypeValidatorTests_IsValid.cs

@@ -0,0 +1,31 @@
+using System.Collections.Generic;
+using System.Globalization;
+using System.Threading;
+using Nop.Plugin.Api.DTOs.Products;
+using NUnit.Framework;
+using Nop.Plugin.Api.Tests.SerializersTests.DummyObjects;
+using Nop.Plugin.Api.Validators;
+
+namespace Nop.Plugin.Api.Tests.ValidatorTests
+{
+    public class TypeValidatorTests_IsValid
+    {
+        [Test]
+        [SetCulture("de-de")]
+        [Description("Regression test for issue #11 - https://github.com/SevenSpikes/api-plugin-for-nopcommerce/issues/11")]
+        public void WhenCurrentCultureUsesCommaAsDecimalPoint_ShouldProperlyValidateProductPrice()
+        {
+            //Arange
+            Dictionary<string, object> properties = new Dictionary<string, object>();
+            properties.Add("price", 33.33);
+
+            var cut = new TypeValidator<ProductDto>();
+
+            //Act
+            bool result = cut.IsValid(properties);
+
+            // Assert
+            Assert.IsTrue(result);
+        }
+    }
+}

Nop.Plugin.Api/Validators/TypeValidator.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.ComponentModel;
+using System.Globalization;
 using System.Reflection;
 using AutoMapper.Configuration;
 using Newtonsoft.Json;
@@ -109,7 +110,7 @@ private bool IsCurrentPropertyValid(Type type, object value)
                 // This is needed because the isValid method does not work well if the value it is trying to validate is object.
                 if (value != null)
                 {
-                    valueToValidate = value.ToString();
+                    valueToValidate = string.Format(CultureInfo.InvariantCulture, "{0}", value);
                 }
 
                 if (!converter.IsValid(valueToValidate)) isCurrentPropertyValid = false;