Fixed a errors leading to null reference exceptions in the ReflectionHelpers class

Author: Taritsyn

global.json

@@ -1,5 +1,5 @@
 {
 	"sdk": {
-		"version": "3.0.100"
+		"version": "3.0.101"
 	}
 }

src/MsieJavaScriptEngine/Helpers/ReflectionHelpers.cs

@@ -70,6 +70,11 @@ public static MethodInfo[] GetFullyFledgedMethods(MethodInfo[] methods)
 
 		public static void FixFieldValueType(ref object value, FieldInfo field)
 		{
+			if (value == null)
+			{
+				return;
+			}
+
 			Type valueType = value.GetType();
 			Type fieldType = field.FieldType;
 
@@ -86,6 +91,11 @@ public static void FixFieldValueType(ref object value, FieldInfo field)
 
 		public static void FixPropertyValueType(ref object value, PropertyInfo property)
 		{
+			if (value == null)
+			{
+				return;
+			}
+
 			Type valueType = value.GetType();
 			Type propertyType = property.PropertyType;
 
@@ -107,6 +117,11 @@ public static void FixArgumentTypes(ref object[] argValues, ParameterInfo[] para
 			for (int argIndex = 0; argIndex < argCount; argIndex++)
 			{
 				object argValue = argValues[argIndex];
+				if (argValue == null)
+				{
+					continue;
+				}
+
 				Type argType = argValue.GetType();
 
 				ParameterInfo parameter = parameters[argIndex];
@@ -149,7 +164,7 @@ public static MethodBase GetBestFitMethod(MethodBase[] methods, object[] argValu
 			}
 
 			Type[] argTypes = argValues
-				.Select(a => a.GetType())
+				.Select(a => a != null ? a.GetType() : typeof(object))
 				.ToArray()
 				;
 			var compatibleMethods = new List<MethodWithMetadata>();

src/MsieJavaScriptEngine/MsieJavaScriptEngine.csproj

@@ -24,8 +24,7 @@
 		<IncludeSymbols>true</IncludeSymbols>
 		<SymbolPackageFormat>snupkg</SymbolPackageFormat>
 		<PackageTags>JavaScript;ECMAScript;MSIE;IE;Edge;Chakra</PackageTags>
-		<PackageReleaseNotes>1. Fixed a error that caused a crash during finalization;
-2. In JsRT modes during calling of the `CollectGarbage` method is again not performed blocking.</PackageReleaseNotes>
+		<PackageReleaseNotes>Fixed a errors leading to null reference exceptions in the `ReflectionHelpers` class. Special thanks to Vanjoge.</PackageReleaseNotes>
 		<NeutralLanguage>en-US</NeutralLanguage>
 		<PackageOutputPath>../../nuget</PackageOutputPath>
 		<GeneratePackageOnBuild Condition=" '$(Configuration)' == 'Release' ">true</GeneratePackageOnBuild>

src/MsieJavaScriptEngine/readme.txt

@@ -21,9 +21,8 @@
    =============
    RELEASE NOTES
    =============
-   1. Fixed a error that caused a crash during finalization;
-   2. In JsRT modes during calling of the `CollectGarbage` method is again not
-      performed blocking.
+   Fixed a errors leading to null reference exceptions in the `ReflectionHelpers`
+   class. Special thanks to Vanjoge.
 
    ============
    PROJECT SITE

test/MsieJavaScriptEngine.Test.Common/Interop/FileManager.cs

@@ -1,18 +1,26 @@
 using System;
 using System.IO;
+using System.Text;
 
 namespace MsieJavaScriptEngine.Test.Common.Interop
 {
 	public sealed class FileManager
 	{
 		public string ReadFile(string path)
+		{
+			return ReadFile(path, null);
+		}
+
+		public string ReadFile(string path, Encoding encoding)
 		{
 			if (path == null)
 			{
 				throw new ArgumentNullException("path");
 			}
 
-			string content = File.ReadAllText(path);
+			encoding = encoding ?? Encoding.UTF8;
+
+			string content = File.ReadAllText(path, encoding);
 
 			return content;
 		}

test/MsieJavaScriptEngine.Test.Common/Interop/Person.cs

@@ -14,15 +14,26 @@ public string LastName
 			set;
 		}
 
+		public string Patronymic
+		{
+			get;
+			set;
+		}
+
 
 		public Person()
 			: this(string.Empty, string.Empty)
 		{ }
 
 		public Person(string firstName, string lastName)
+			: this(firstName, lastName, string.Empty)
+		{ }
+
+		public Person(string firstName, string lastName, string patronymic)
 		{
 			FirstName = firstName;
 			LastName = lastName;
+			Patronymic = patronymic;
 		}
 
 

test/MsieJavaScriptEngine.Test.Common/Interop/Product.cs

@@ -3,6 +3,7 @@
 	public sealed class Product
 	{
 		public string Name;
+		public string Description;
 		public double Price;
 	}
 }

test/MsieJavaScriptEngine.Test.Common/InteropTestsBase.cs

@@ -69,33 +69,41 @@ public virtual void EmbeddingOfInstanceOfCustomReferenceTypeWithFieldsIsCorrect(
 			var product = new Product
 			{
 				Name = "Red T-shirt",
+				Description = string.Empty,
 				Price = 995.00
 			};
 
-			const string updateCode = "product.Price *= 1.15;";
+			const string updateCode = @"product.Description = null;
+product.Price *= 1.15;";
 
 			const string input1 = "product.Name";
 			const string targetOutput1 = "Red T-shirt";
 
-			const string input2 = "product.Price";
-			const double targetOutput2 = 1144.25;
+			const string input2 = "product.Description";
+			const string targetOutput2 = null;
+
+			const string input3 = "product.Price";
+			const double targetOutput3 = 1144.25;
 
 			// Act
 			string output1;
-			double output2;
+			string output2;
+			double output3;
 
 			using (var jsEngine = CreateJsEngine())
 			{
 				jsEngine.EmbedHostObject("product", product);
 				jsEngine.Execute(updateCode);
 
 				output1 = jsEngine.Evaluate<string>(input1);
-				output2 = jsEngine.Evaluate<double>(input2);
+				output2 = jsEngine.Evaluate<string>(input2);
+				output3 = jsEngine.Evaluate<double>(input3);
 			}
 
 			// Assert
 			Assert.AreEqual(targetOutput1, output1);
 			Assert.AreEqual(targetOutput2, output2);
+			Assert.AreEqual(targetOutput3, output3);
 		}
 
 		#endregion
@@ -218,17 +226,22 @@ public virtual void EmbeddingOfInstanceOfCustomReferenceTypeWithPropertiesIsCorr
 		{
 			// Arrange
 			var person = new Person("Vanya", "Ivanov");
-			const string updateCode = "person.LastName = person.LastName.substr(0, 5) + 'ff';";
+			const string updateCode = @"person.LastName = person.LastName.substr(0, 5) + 'ff';
+person.Patronymic = null;";
 
 			const string input1 = "person.FirstName";
 			const string targetOutput1 = "Vanya";
 
 			const string input2 = "person.LastName";
 			const string targetOutput2 = "Ivanoff";
 
+			const string input3 = "person.Patronymic";
+			const string targetOutput3 = null;
+
 			// Act
 			string output1;
 			string output2;
+			string output3;
 
 			using (var jsEngine = CreateJsEngine())
 			{
@@ -237,11 +250,13 @@ public virtual void EmbeddingOfInstanceOfCustomReferenceTypeWithPropertiesIsCorr
 
 				output1 = jsEngine.Evaluate<string>(input1);
 				output2 = jsEngine.Evaluate<string>(input2);
+				output3 = jsEngine.Evaluate<string>(input3);
 			}
 
 			// Assert
 			Assert.AreEqual(targetOutput1, output1);
 			Assert.AreEqual(targetOutput2, output2);
+			Assert.AreEqual(targetOutput3, output3);
 		}
 
 		[Test]
@@ -405,7 +420,7 @@ public virtual void EmbeddingOfInstanceOfCustomReferenceTypeWithMethodIsCorrect(
 			var fileManager = new FileManager();
 			string filePath = GetAbsolutePath("SharedFiles/link.txt");
 
-			string input = string.Format("fileManager.ReadFile('{0}')", filePath.Replace(@"\", @"\\"));
+			string input = string.Format("fileManager.ReadFile('{0}', null)", filePath.Replace(@"\", @"\\"));
 			const string targetOutput = "http://www.panopticoncentral.net/2015/09/09/the-two-faces-of-jsrt-in-windows-10/";
 
 			// Act