Updated how handlers are resolved, and when they are resolved.

Changed how capabilities are made available.
Added additional callbacks

Author: david-driscoll

sample/SampleServer/Program.cs

@@ -21,15 +21,14 @@ static async Task MainAsync(string[] args)
             //    await Task.Delay(100);
             //}
 
-            var server = LanguageServer.From(options =>
+            var server = await LanguageServer.From(options =>
                 options
                     .WithInput(Console.OpenStandardInput())
                     .WithOutput(Console.OpenStandardOutput())
                     .WithLoggerFactory(new LoggerFactory()));
 
-            server.AddHandler(new TextDocumentHandler(server));
+            server.AddHandlers(new TextDocumentHandler(server));
 
-            await server.Initialize();
             await server.WaitForExit;
         }
     }

sample/SampleServer/TextDocumentHandler.cs

@@ -29,17 +29,7 @@ public TextDocumentHandler(ILanguageServer router)
             _router = router;
         }
 
-        public TextDocumentSyncOptions Options { get; } = new TextDocumentSyncOptions()
-        {
-            WillSaveWaitUntil = false,
-            WillSave = true,
-            Change = TextDocumentSyncKind.Full,
-            Save = new SaveOptions()
-            {
-                IncludeText = true
-            },
-            OpenClose = true
-        };
+        public TextDocumentSyncKind Change { get; } = TextDocumentSyncKind.Full;
 
         public Task Handle(DidChangeTextDocumentParams notification, CancellationToken token)
         {
@@ -56,7 +46,7 @@ TextDocumentChangeRegistrationOptions IRegistration<TextDocumentChangeRegistrati
             return new TextDocumentChangeRegistrationOptions()
             {
                 DocumentSelector = _documentSelector,
-                SyncKind = Options.Change
+                SyncKind = Change
             };
         }
 
@@ -98,7 +88,7 @@ TextDocumentSaveRegistrationOptions IRegistration<TextDocumentSaveRegistrationOp
             return new TextDocumentSaveRegistrationOptions()
             {
                 DocumentSelector = _documentSelector,
-                IncludeText = Options.Save.IncludeText
+                IncludeText = true
             };
         }
         public TextDocumentAttributes GetTextDocumentAttributes(Uri uri)

src/Client/LanguageClient.cs

@@ -92,7 +92,7 @@ public LanguageClient(ILoggerFactory loggerFactory, ServerProcess process)
                 throw new ArgumentNullException(nameof(process));
 
             _process = process;
-            _process.Exited += ServerProcess_Exit;
+            _process.Exited.Subscribe(x => ServerProcess_Exit());
         }
 
         /// <summary>
@@ -452,7 +452,7 @@ async Task Start()
         /// <param name="args">
         ///     The event arguments.
         /// </param>
-        async void ServerProcess_Exit(object sender, EventArgs args)
+        async void ServerProcess_Exit()
         {
             Log.LogDebug("Server process has exited; language client is shutting down...");
 

src/Client/Processes/ServerProcess.cs

@@ -1,5 +1,7 @@
-using System;
+using System;
 using System.IO;
+using System.Reactive.Linq;
+using System.Reactive.Subjects;
 using System.Threading.Tasks;
 using Microsoft.Extensions.Logging;
 
@@ -11,6 +13,7 @@ namespace OmniSharp.Extensions.LanguageServer.Client.Processes
     public abstract class ServerProcess
         : IDisposable
     {
+        private readonly ISubject<System.Reactive.Unit> _exitedSubject;
         /// <summary>
         ///     Create a new <see cref="ServerProcess"/>.
         /// </summary>
@@ -31,6 +34,8 @@ protected ServerProcess(ILoggerFactory loggerFactory)
 
             ServerExitCompletion = new TaskCompletionSource<object>();
             ServerExitCompletion.SetResult(null); // Start out as if the server has already exited.
+
+            Exited = _exitedSubject = new AsyncSubject<System.Reactive.Unit>();
         }
 
         /// <summary>
@@ -82,7 +87,7 @@ protected virtual void Dispose(bool disposing)
         /// <summary>
         ///     Event raised when the server has exited.
         /// </summary>
-        public event EventHandler<EventArgs> Exited;
+        public IObservable<System.Reactive.Unit> Exited { get; }
 
         /// <summary>
         ///     Is the server running?
@@ -130,7 +135,8 @@ protected virtual void Dispose(bool disposing)
         /// </summary>
         protected virtual void OnExited()
         {
-            Exited?.Invoke(this, EventArgs.Empty);
+            _exitedSubject.OnNext(System.Reactive.Unit.Default);
+            _exitedSubject.OnCompleted();
         }
     }
 }

src/JsonRpc/HandlerCollection.cs

@@ -19,6 +19,7 @@ public HandlerInstance(string method, IJsonRpcHandler handler, Type handlerInter
             {
                 _disposeAction = disposeAction;
                 Handler = handler;
+                ImplementationType = handler.GetType();
                 Method = method;
                 HandlerType = handlerInterface;
                 Params = @params;
@@ -27,6 +28,7 @@ public HandlerInstance(string method, IJsonRpcHandler handler, Type handlerInter
 
             public IJsonRpcHandler Handler { get; }
             public Type HandlerType { get; }
+            public Type ImplementationType { get; }
             public string Method { get; }
             public Type Params { get; }
             public Type Response { get; }

src/JsonRpc/IHandlerDescriptor.cs

@@ -5,9 +5,10 @@ namespace OmniSharp.Extensions.JsonRpc
     public interface IHandlerDescriptor
     {
         string Method { get; }
-        IJsonRpcHandler Handler { get; }
         Type HandlerType { get; }
+        Type ImplementationType { get; }
         Type Params { get; }
         Type Response { get; }
+        IJsonRpcHandler Handler { get; }
     }
 }

src/Protocol/Client/Capabilities/SynchronizationCapability.cs

@@ -4,7 +4,7 @@
 
 namespace OmniSharp.Extensions.LanguageServer.Protocol.Client.Capabilities
 {
-    public class SynchronizationCapability : DynamicCapability, ConnectedCapability<ITextDocumentSyncHandler>
+    public class SynchronizationCapability : DynamicCapability
     {
         /// <summary>
         /// The client supports sending will save notifications.

src/Protocol/Document/IDidChangeTextDocumentHandler.cs

@@ -1,6 +1,7 @@
 using OmniSharp.Extensions.JsonRpc;
 using OmniSharp.Extensions.LanguageServer.Protocol.Client.Capabilities;
 using OmniSharp.Extensions.LanguageServer.Protocol.Models;
+using OmniSharp.Extensions.LanguageServer.Protocol.Server.Capabilities;
 
 // ReSharper disable CheckNamespace
 
@@ -13,5 +14,9 @@ public static partial class DocumentNames
     }
 
     [Serial, Method(DidChange)]
-    public interface IDidChangeTextDocumentHandler : IJsonRpcNotificationHandler<DidChangeTextDocumentParams>, IRegistration<TextDocumentChangeRegistrationOptions>, ICapability<SynchronizationCapability> { }
+    public interface IDidChangeTextDocumentHandler : IJsonRpcNotificationHandler<DidChangeTextDocumentParams>,
+        IRegistration<TextDocumentChangeRegistrationOptions>, ICapability<SynchronizationCapability>
+    {
+        TextDocumentSyncKind Change { get; }
+    }
 }

src/Protocol/Document/ITextDocumentIdentifier.cs

@@ -0,0 +1,14 @@
+using System;
+
+namespace OmniSharp.Extensions.LanguageServer.Protocol
+{
+    public interface ITextDocumentIdentifier
+    {
+        /// <summary>
+        /// Returns the attributes for the document at the given URI.  This can return null.
+        /// </summary>
+        /// <param name="uri"></param>
+        /// <returns></returns>
+        TextDocumentAttributes GetTextDocumentAttributes(Uri uri);
+    }
+}

src/Protocol/Document/ITextDocumentSyncHandler.cs

@@ -1,18 +1,10 @@
-using System;
 using OmniSharp.Extensions.LanguageServer.Protocol.Server.Capabilities;
 
 // ReSharper disable CheckNamespace
 
 namespace OmniSharp.Extensions.LanguageServer.Protocol
 {
-    public interface ITextDocumentSyncHandler : IDidChangeTextDocumentHandler, IDidOpenTextDocumentHandler, IDidCloseTextDocumentHandler, IDidSaveTextDocumentHandler
+    public interface ITextDocumentSyncHandler : IDidChangeTextDocumentHandler, IDidOpenTextDocumentHandler, IDidCloseTextDocumentHandler, IDidSaveTextDocumentHandler, ITextDocumentIdentifier
     {
-        TextDocumentSyncOptions Options { get; }
-        /// <summary>
-        /// Returns the attributes for the document at the given URI.  This can return null.
-        /// </summary>
-        /// <param name="uri"></param>
-        /// <returns></returns>
-        TextDocumentAttributes GetTextDocumentAttributes(Uri uri);
     }
 }