Fix Type.GetGenericTypeDefinition() interface error (#166)

Author: Arkatufus

src/Hyperion.Tests/GenericDictionarySerializerTests.cs

@@ -71,10 +71,15 @@ public ProtectedCustomDictionary(Dictionary<TKey, TValue> dict) : base(new Dicti
             { }
         }
 
+        // Dictionary serializer fails to fetch the generic IDictionary interface if
+        // Type.GetInterfaces() returns a non-generic interface before the IDictionary interface
         /// <summary>
         /// Just a custom class wrapper for another <see cref="IDictionary{TKey,TValue}"/>
         /// </summary>
-        class CustomDictionary<TKey, TValue> : IDictionary<TKey, TValue>
+        class CustomDictionary<TKey, TValue> :
+            IEnumerable, 
+            IDictionary<TKey, TValue>, 
+            IEquatable<CustomDictionary<TKey, TValue>>
         {
             private readonly IDictionary<TKey, TValue> _dictGeneric;
 
@@ -162,6 +167,11 @@ public bool TryGetValue(TKey key, out TValue value)
                 return _dictGeneric.TryGetValue(key, out value);
             }
 
+            public bool Equals(CustomDictionary<TKey, TValue> other)
+            {
+                return true;
+            }
+
             /// <inheritdoc />
             public TValue this[TKey key]
             {

src/Hyperion/SerializerFactories/DictionarySerializerFactory.cs

@@ -97,7 +97,10 @@ public override ValueSerializer BuildSerializer(Serializer serializer, Type type
 
         private GenericDictionaryTypes GetKeyValuePairType(Type dictImplementationType)
         {
-            var dictInterface = dictImplementationType.GetInterfaces().First(i => i.GetGenericTypeDefinition() == typeof (IDictionary<,>));
+            var dictInterface = dictImplementationType
+                .GetInterfaces()
+                .Where(i => i.GetTypeInfo().IsGenericType)
+                .First(i => i.GetGenericTypeDefinition() == typeof(IDictionary<,>));
             var keyType = dictInterface.GetGenericArguments()[0];
             var valueType = dictInterface.GetGenericArguments()[1];
             return new GenericDictionaryTypes()