Added null checks and removed GetPropertyType.

Author: LuukN2

src/Common.OData.ApiExplorer/AspNet.OData/ClassProperty.cs

@@ -11,7 +11,7 @@
 
     struct ClassProperty
     {
-        readonly Type type;
+        internal readonly Type Type;
         internal readonly string Name;
 
         internal ClassProperty( PropertyInfo clrProperty, Type propertyType )
@@ -20,14 +20,16 @@ internal ClassProperty( PropertyInfo clrProperty, Type propertyType )
             Contract.Requires( propertyType != null );
 
             Name = clrProperty.Name;
-            type = propertyType;
+            Type = propertyType;
             Attributes = AttributesFromProperty( clrProperty );
         }
 
         internal ClassProperty( IServiceProvider services, IEnumerable<Assembly> assemblies, IEdmOperationParameter parameter, IModelTypeBuilder typeBuilder )
         {
+            Contract.Requires( services != null );
             Contract.Requires( assemblies != null );
             Contract.Requires( parameter != null );
+            Contract.Requires( typeBuilder != null );
 
             Name = parameter.Name;
             var context = new TypeSubstitutionContext( services, assemblies, typeBuilder );
@@ -38,26 +40,21 @@ internal ClassProperty( IServiceProvider services, IEnumerable<Assembly> assembl
                 var elementType = collectionType.ElementType().Definition.GetClrType( assemblies );
                 var substitutedType = elementType.SubstituteIfNecessary( context );
 
-                type = typeof( IEnumerable<> ).MakeGenericType( substitutedType );
+                Type = typeof( IEnumerable<> ).MakeGenericType( substitutedType );
             }
             else
             {
                 var parameterType = parameter.Type.Definition.GetClrType( assemblies );
 
-                type = parameterType.SubstituteIfNecessary( context );
+                Type = parameterType.SubstituteIfNecessary( context );
             }
 
             Attributes = AttributesFromOperationParameter( parameter );
         }
 
         internal IEnumerable<CustomAttributeBuilder> Attributes { get; }
 
-        public override int GetHashCode() => ( Name.GetHashCode() * 397 ) ^ type.GetHashCode();
-
-        public Type GetPropertyType()
-        {
-            return type;
-        }
+        public override int GetHashCode() => ( Name.GetHashCode() * 397 ) ^ Type.GetHashCode();
 
         static IEnumerable<CustomAttributeBuilder> AttributesFromProperty( PropertyInfo clrProperty )
         {

src/Common.OData.ApiExplorer/AspNet.OData/DefaultModelTypeBuilder.cs

@@ -173,6 +173,7 @@ public Type NewStructuredType( IEdmStructuredType structuredType, Type clrType,
         /// <inheritdoc />
         public Type NewActionParameters( IServiceProvider services, IEdmAction action, ApiVersion apiVersion )
         {
+            Arg.NotNull( services, nameof( services ) );
             Arg.NotNull( action, nameof( action ) );
             Arg.NotNull( apiVersion, nameof( apiVersion ) );
             Contract.Ensures( Contract.Result<Type>() != null );
@@ -202,7 +203,7 @@ TypeBuilder CreateTypeBuilderFromSignature( ClassSignature @class )
 
             foreach ( var property in @class.Properties )
             {
-                var type = property.GetPropertyType();
+                var type = property.Type;
                 var name = property.Name;
                 var propertyBuilder = AddProperty( typeBuilder, type, name );