Attemt to make HasHandler to work correctly

Author: david-driscoll

src/Lsp/HandlerCollection.cs

@@ -37,7 +37,7 @@ public IDisposable Add(IEnumerable<IJsonRpcHandler> handlers)
                     .ImplementedInterfaces
                     .Where(x => !string.IsNullOrWhiteSpace(LspHelper.GetMethodName(x))))
                 {
-                    var @interface = GetHandlerInterface(implementedInterface);
+                    var @interface = HandlerTypeHelpers.GetHandlerInterface(implementedInterface);
                     var registration = UnwrapGenericType(typeof(IRegistration<>), implementedInterface);
                     var capability = UnwrapGenericType(typeof(ICapability<>), implementedInterface);
 
@@ -72,24 +72,6 @@ public IDisposable Add(IEnumerable<IJsonRpcHandler> handlers)
             return new ImutableDisposable(descriptors);
         }
 
-        private static readonly Type[] HandlerTypes = { typeof(INotificationHandler), typeof(INotificationHandler<>), typeof(IRequestHandler<>), typeof(IRequestHandler<,>), };
-
-        private bool IsValidInterface(Type type)
-        {
-            if (type.GetTypeInfo().IsGenericType)
-            {
-                return HandlerTypes.Contains(type.GetGenericTypeDefinition());
-            }
-            return HandlerTypes.Contains(type);
-        }
-
-        private Type GetHandlerInterface(Type type)
-        {
-            return type?.GetTypeInfo()
-                .ImplementedInterfaces
-                .First(IsValidInterface);
-        }
-
         private Type UnwrapGenericType(Type genericType, Type type)
         {
             return type?.GetTypeInfo()

src/Lsp/HandlerDescriptor.cs

@@ -36,7 +36,8 @@ public HandlerDescriptor(string method, string key, IJsonRpcHandler handler, Typ
 
         public Registration Registration
         {
-            get {
+            get
+            {
                 if (!HasRegistration) return null;
                 if (_registration != null) return _registration;
 
@@ -47,7 +48,8 @@ public Registration Registration
                     .MakeGenericMethod(RegistrationType)
                     .Invoke(this, new object[] { Handler });
 
-                return _registration = new Registration() {
+                return _registration = new Registration()
+                {
                     Id = Guid.NewGuid().ToString(),
                     Method = Method,
                     RegisterOptions = options

src/Lsp/HandlerTypeHelpers.cs

@@ -0,0 +1,28 @@
+using System;
+using System.Linq;
+using System.Reflection;
+using OmniSharp.Extensions.JsonRpc;
+
+namespace OmniSharp.Extensions.LanguageServer
+{
+    public static class HandlerTypeHelpers
+    {
+        private static readonly Type[] HandlerTypes = { typeof(INotificationHandler), typeof(INotificationHandler<>), typeof(IRequestHandler<>), typeof(IRequestHandler<,>), };
+
+        private static bool IsValidInterface(Type type)
+        {
+            if (type.GetTypeInfo().IsGenericType)
+            {
+                return HandlerTypes.Contains(type.GetGenericTypeDefinition());
+            }
+            return HandlerTypes.Contains(type);
+        }
+
+        public static Type GetHandlerInterface(Type type)
+        {
+            return type?.GetTypeInfo()
+                .ImplementedInterfaces
+                .First(IsValidInterface);
+        }
+    }
+}

src/Lsp/LanguageServer.cs

@@ -196,7 +196,7 @@ public Task Handle()
 
         private bool HasHandler<T>()
         {
-            return _collection.Any(z => z.HandlerType == typeof(T));
+            return _collection.Any(z => z.Handler is T);
         }
 
         private T GetOptions<O, T>(Func<O, T> action)