fixed issue with non object JTokens in resolve command matcher. Determined that HandlerDescriptor was setting CanBeResolvedHandlerType incorrectly for some cases

Author: david-driscoll

src/Server/HandlerDescriptor.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using System.Reflection;
 using OmniSharp.Extensions.JsonRpc;
 using OmniSharp.Extensions.LanguageServer.Protocol;
@@ -23,10 +24,11 @@ public HandlerDescriptor(string method, string key, IJsonRpcHandler handler, Typ
             Params = @params;
             RegistrationType = registrationType;
             CapabilityType = capabilityType;
-            if (@params != null && typeof(ICanBeResolved).GetTypeInfo().IsAssignableFrom(@params))
-            {
-                CanBeResolvedHandlerType = typeof(ICanBeResolvedHandler<>).MakeGenericType(@params);
-            }
+
+            // If multiple are implemented this behavior is unknown
+            CanBeResolvedHandlerType = handler.GetType().GetTypeInfo()
+                .ImplementedInterfaces
+                .FirstOrDefault(x => x.GetTypeInfo().IsGenericType && x.GetTypeInfo().GetGenericTypeDefinition() == typeof(ICanBeResolvedHandler<>));
         }
 
         public IJsonRpcHandler Handler { get; }

src/Server/Matchers/ResolveCommandMatcher.cs

@@ -30,8 +30,8 @@ public IEnumerable<ILspHandlerDescriptor> FindHandler(object parameters, IEnumer
             if (parameters is ICanBeResolved canBeResolved)
             {
                 string handlerType = null;
-                if (canBeResolved.Data != null)
-                    handlerType = canBeResolved.Data.Value<string>(PrivateHandlerTypeName);
+                if (canBeResolved.Data != null && canBeResolved.Data.Type == JTokenType.Object)
+                    handlerType = canBeResolved.Data?[PrivateHandlerTypeName]?.ToString();
 
                 if (string.IsNullOrWhiteSpace(handlerType))
                 {

test/Lsp.Tests/Matchers/ResolveCommandMatcherTests.cs

@@ -139,6 +139,35 @@ public void Should_Handle_Null_Data()
             result.Should().Contain(x => x.Handler == resolveHandler);
         }
 
+        [Fact]
+        public void Should_Handle_Simple_Json_Data()
+        {
+            // Given
+            var handlerMatcher = new ResolveCommandMatcher(_logger);
+            var resolveHandler = Substitute.For<ICompletionResolveHandler>();
+            resolveHandler.CanResolve(Arg.Any<CompletionItem>()).Returns(true);
+
+            // When
+            var result = handlerMatcher.FindHandler(new CompletionItem() {
+                Data = new Uri("file:///c%3A/Users/mb/src/gh/Cake.Json/src/Cake.Json/Namespaces.cs")
+            },
+                    new List<HandlerDescriptor> {
+                        new HandlerDescriptor(DocumentNames.CompletionResolve,
+                            "Key",
+                            resolveHandler,
+                            resolveHandler.GetType(),
+                            typeof(CompletionItem),
+                            null,
+                            null,
+                            () => { }),
+                    })
+                .ToArray();
+
+            // Then
+            result.Should().NotBeNullOrEmpty();
+            result.Should().Contain(x => x.Handler == resolveHandler);
+        }
+
         [Fact]
         public void Should_Return_CompletionResolve_Descriptor()
         {
@@ -296,7 +325,7 @@ public void Should_FindPostProcessor_AsSelf_For_Completion()
                             "Key",
                             resolveHandler,
                             resolveHandler.GetType(),
-                            typeof(CodeLensParams),
+                            typeof(CompletionParams),
                             null,
                             null,
                             () => { });
@@ -325,7 +354,7 @@ public void Should_Update_CompletionItems_With_HandlerType()
                             "Key",
                             resolveHandler as IJsonRpcHandler,
                             resolveHandler.GetType(),
-                            typeof(CompletionItem),
+                            typeof(CompletionParams),
                             null,
                             null,
                             () => { });
@@ -363,7 +392,7 @@ public void Should_Update_CodeLensContainer_With_HandlerType()
                             "Key",
                             resolveHandler as IJsonRpcHandler,
                             resolveHandler.GetType(),
-                            typeof(CodeLens),
+                            typeof(CodeLensParams),
                             null,
                             null,
                             () => { });