Polished unit tests

Fixed cyclical graph type reference
Added exception handling

GraphQL-Core.Tests/Initialize.cs

@@ -1,5 +1,6 @@
 using GraphQL;
 using GraphQL.Types;
+using GraphQLCore;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 using Newtonsoft.Json.Linq;
@@ -32,6 +33,7 @@ public void Init()
 
                 return service.ImplementationInstance;
             });
+            GraphQLCoreTypeWrapperGenerator.Clear();
         }
 
         public (bool error, ExecutionResult) Ask(string query, string operation, JObject variables)

GraphQL-Core.Tests/TypeTests.cs

@@ -118,7 +118,7 @@ public void Test_AddType_HasFields(Type T)
         [TestMethod]
         [TestCategory("Types")]
         [DataTestMethod()]
-        //[DataRow(typeof(Book))]
+        [DataRow(typeof(Book))]
         [DataRow(typeof(Book_WithValueTypes))]
         [DataRow(typeof(Book_WithEnumTypes))]
         [DataRow(typeof(Book_WithEnumerables))]
@@ -127,8 +127,6 @@ public void Test_AddType_HasFields(Type T)
         [DataRow(typeof(Author))]
         [DataRow(typeof(Author_WithValueTypes))]
         [DataRow(typeof(Author_WithEnumTypes))]
-        [DataRow(typeof(Author_WithEnumerableBooks))]
-        [DataRow(typeof(Author_WithManyManyBooks))]
         [DataRow(typeof(Book_WithDuplicateBaseTypes))]
         [DataRow(typeof(Book_WithTwoAuthors))]
         [DataRow(typeof(Book_WithVirtualAuthorAndId))]

GraphQL-Core/CSharpClassBuilder.cs

@@ -1,4 +1,5 @@
-using GraphQLCore.Types;
+using GraphQLCore.Exceptions;
+using GraphQLCore.Types;
 using System;
 using System.Collections.Generic;
 using System.Reflection;
@@ -21,23 +22,30 @@ public static class GraphQLCoreTypeWrapperGenerator
 
         public static Type CreateGraphQLTypeWrapper<T>()
         {
-            if (genericTypeParentClasses.ContainsKey(typeof(GenericType<T>)))
-                return genericTypeParentClasses[typeof(GenericType<T>)];
+            try
+            {
+                if (genericTypeParentClasses.ContainsKey(typeof(GenericType<T>)))
+                    return genericTypeParentClasses[typeof(GenericType<T>)];
 
-            TypeBuilder tb = GetTypeBuilder(typeof(T).Name + typeNameAppend, typeof(GenericType<T>));
-            tb.DefineDefaultConstructor(
-                MethodAttributes.Public 
-                | MethodAttributes.SpecialName 
-                | MethodAttributes.RTSpecialName);
+                TypeBuilder tb = GetTypeBuilder(typeof(T).Name + typeNameAppend, typeof(GenericType<T>));
+                tb.DefineDefaultConstructor(
+                    MethodAttributes.Public
+                    | MethodAttributes.SpecialName
+                    | MethodAttributes.RTSpecialName);
 
-            tb.SetParent(typeof(GenericType<T>));
+                tb.SetParent(typeof(GenericType<T>));
 
-            TypeInfo objectTypeInfo = tb.CreateTypeInfo();
-            Type type = objectTypeInfo.AsType();
+                TypeInfo objectTypeInfo = tb.CreateTypeInfo();
+                Type type = objectTypeInfo.AsType();
 
-            genericTypeParentClasses[typeof(GenericType<T>)] = type;
+                genericTypeParentClasses[typeof(GenericType<T>)] = type;
 
-            return type;
+                return type;
+            }
+            catch(Exception e)
+            {
+                throw new GraphQLCoreMSILException("Attempt to create new C# type failed. Refer to inner exception for details", e);
+            }
         }
 
         public static Type GetDerivedGenericUserType<T>()
@@ -58,28 +66,49 @@ public static Type GetDerivedGenericUserType(this Type T)
 
         private static AssemblyName CreateDynamicAssemblyName()
         {
-            var currentAssemblyName = Assembly.GetEntryAssembly().GetName().Clone() as AssemblyName;
-            var asmName = new AssemblyName(Guid.NewGuid().ToString());
-            asmName.Name = currentAssemblyName.Name + asmNameAppend;
-            return currentAssemblyName;
+            try
+            {
+                var currentAssemblyName = Assembly.GetEntryAssembly().GetName().Clone() as AssemblyName;
+                var asmName = new AssemblyName(Guid.NewGuid().ToString());
+                asmName.Name = currentAssemblyName.Name + asmNameAppend;
+                return currentAssemblyName;
+            }
+            catch(Exception e)
+            {
+                throw new GraphQLCoreAssemblyException("Attempt to create new dynamic assembly failed. Refer to inner exception for details", e);
+            }
         }
 
         private static TypeBuilder GetTypeBuilder(string typeName, Type baseClass)
         {
-            var typeSignature = typeName;
-
-            if(mdBuilder is null)
-                mdBuilder = asmBuilder.DefineDynamicModule(mdName);
-
-            TypeBuilder tb = mdBuilder.DefineType(typeSignature,
-                    TypeAttributes.Public |
-                    TypeAttributes.Class |
-                    TypeAttributes.AutoClass |
-                    TypeAttributes.AnsiClass |
-                    TypeAttributes.BeforeFieldInit |
-                    TypeAttributes.AutoLayout,
-                    baseClass);
-            return tb;
+            try
+            {
+                var typeSignature = typeName;
+
+                if (mdBuilder is null)
+                    mdBuilder = asmBuilder.DefineDynamicModule(mdName);
+
+                TypeBuilder tb = mdBuilder.DefineType(typeSignature,
+                        TypeAttributes.Public |
+                        TypeAttributes.Class |
+                        TypeAttributes.AutoClass |
+                        TypeAttributes.AnsiClass |
+                        TypeAttributes.BeforeFieldInit |
+                        TypeAttributes.AutoLayout,
+                        baseClass);
+                return tb;
+            }
+            catch(Exception e)
+            {
+                throw new GraphQLCoreClassDefinitionException("Attempt to define a new C# type failed. Refer to inner exception for details", e);
+            }
+        }
+
+        public static void Clear()
+        {
+            genericTypeParentClasses.Clear();
+            mdBuilder = null;
+            asmBuilder = AssemblyBuilder.DefineDynamicAssembly(CreateDynamicAssemblyName(), AssemblyBuilderAccess.Run);
         }
     }
 }

GraphQL-Core/Exceptions/BuilderExceptions.cs

@@ -0,0 +1,20 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace GraphQLCore.Exceptions
+{
+    public class GraphQLCoreStitchException : Exception
+    {
+        public GraphQLCoreStitchException() { }
+        public GraphQLCoreStitchException(string message) : base(message) { }
+        public GraphQLCoreStitchException(string message, Exception inner) : base(message, inner) { }
+    }
+
+    public class GraphQLCoreTypeException : Exception
+    {
+        public GraphQLCoreTypeException() { }
+        public GraphQLCoreTypeException(string message) : base(message) { }
+        public GraphQLCoreTypeException(string message, Exception inner) : base(message, inner) { }
+    }
+}

GraphQL-Core/Exceptions/ExtensionExceptions.cs

@@ -0,0 +1,13 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace GraphQLCore.Exceptions
+{
+    public class GraphQLCoreConversionException : Exception
+    {
+        public GraphQLCoreConversionException() { }
+        public GraphQLCoreConversionException(string message) : base(message) { }
+        public GraphQLCoreConversionException(string message, Exception inner) : base(message, inner) { }
+    }
+}

GraphQL-Core/Exceptions/MSILExceptions.cs

@@ -0,0 +1,27 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace GraphQLCore.Exceptions
+{
+    public class GraphQLCoreMSILException : Exception
+    {
+        public GraphQLCoreMSILException() { }
+        public GraphQLCoreMSILException(string message) : base(message) { }
+        public GraphQLCoreMSILException(string message, Exception inner) : base(message, inner) { }
+    }
+
+    public class GraphQLCoreAssemblyException : Exception
+    {
+        public GraphQLCoreAssemblyException() { }
+        public GraphQLCoreAssemblyException(string message) : base(message) { }
+        public GraphQLCoreAssemblyException(string message, Exception inner) : base(message, inner) { }
+    }
+
+    public class GraphQLCoreClassDefinitionException : Exception
+    {
+        public GraphQLCoreClassDefinitionException() { }
+        public GraphQLCoreClassDefinitionException(string message) : base(message) { }
+        public GraphQLCoreClassDefinitionException(string message, Exception inner) : base(message, inner) { }
+    }
+}