Change TagSupport to use Supports<> helper class (#234)

* Change TagSupport to use Supports<> helper class

This was done through the UI... there may be actual code breaks that I can get to.

* Updated with unit tests

Author: david-driscoll

src/Protocol/Client/Capabilities/CompletionItemCapability.cs

@@ -43,7 +43,6 @@ public class CompletionItemCapability
         [Optional]
         public bool PreselectSupport { get; set; }
 
-
         /// <summary>
         /// Client supports the tag property on a completion item. Clients supporting
         /// tags have to handle unknown tags gracefully. Clients especially need to
@@ -53,6 +52,6 @@ public class CompletionItemCapability
         /// @since 3.15.0
         /// </summary>
         [Optional]
-        public CompletionItemTagSupportCapability TagSupport { get; set; }
+        public Supports<CompletionItemTagSupportCapability> TagSupport { get; set; }
     }
 }

src/Protocol/Client/Capabilities/PublishDiagnosticsCapability.cs

@@ -20,6 +20,6 @@ public class PublishDiagnosticsCapability
         /// @since 3.15.0
         /// </summary>
         [Optional]
-        public PublishDiagnosticsTagSupportCapability TagSupport { get; set; }
+        public Supports<PublishDiagnosticsTagSupportCapability> TagSupport { get; set; }
     }
 }

src/Protocol/Models/CompletionItemTag.cs

@@ -3,18 +3,18 @@
 
 namespace OmniSharp.Extensions.LanguageServer.Protocol.Models
 {
-    [JsonConverter(typeof(NumberEnumConverter))]
     /// <summary>
     /// Completion item tags are extra annotations that tweak the rendering of a completion
     /// item.
     ///
     /// @since 3.15.0
     /// </summary>
+    [JsonConverter(typeof(NumberEnumConverter))]
     public enum CompletionItemTag
     {
         /// <summary>
         /// Render a completion as obsolete, usually using a strike-out.
         /// </summary>
         Deprecated = 1
     }
-}
+}

src/Protocol/Serialization/ContractResolver.cs

@@ -58,6 +58,11 @@ protected override JsonProperty CreateProperty(MemberInfo member, MemberSerializ
                 property.NullValueHandling = NullValueHandling.Ignore;
             }
 
+            if (typeof(ISupports).IsAssignableFrom(property.PropertyType))
+            {
+                property.ValueProvider = new SupportsValueProvider(property.ValueProvider);
+            }
+
             if (property.DeclaringType == typeof(CompletionItem) && property.PropertyType == typeof(CompletionItemKind))
             {
                 property.ValueProvider = new RangeValueProvider<CompletionItemKind>(property.ValueProvider, _completionItemKinds);
@@ -76,6 +81,27 @@ protected override JsonProperty CreateProperty(MemberInfo member, MemberSerializ
             return property;
         }
 
+        class SupportsValueProvider : IValueProvider
+        {
+            private readonly IValueProvider _valueProvider;
+            public SupportsValueProvider(IValueProvider valueProvider)
+            {
+                _valueProvider = valueProvider;
+            }
+            public void SetValue(object target, object value)
+            {
+                _valueProvider.SetValue(target, value);
+            }
+
+            public object GetValue(object target)
+            {
+                return _valueProvider.GetValue(target) switch {
+                    ISupports supports when supports.IsSupported => supports,
+                    _ => null
+                };
+            }
+        }
+
         class RangeValueProvider<T> : IValueProvider
             where T : struct
         {

src/Protocol/Serialization/Converters/SupportsConverter.cs

@@ -35,7 +35,7 @@ public override void WriteJson(JsonWriter writer, object value, JsonSerializer s
             }
             else
             {
-                serializer.Serialize(writer, null);
+                writer.WriteNull();
             }
         }
 

test/Lsp.Tests/Capabilities/Client/CompletionItemCapabilityTests.cs

@@ -1,8 +1,10 @@
 using System;
+using System.Linq;
 using FluentAssertions;
 using Newtonsoft.Json;
 using OmniSharp.Extensions.LanguageServer.Protocol;
 using OmniSharp.Extensions.LanguageServer.Protocol.Client.Capabilities;
+using OmniSharp.Extensions.LanguageServer.Protocol.Models;
 using OmniSharp.Extensions.LanguageServer.Protocol.Serialization;
 using Xunit;
 
@@ -24,5 +26,22 @@ public void SimpleTest(string expected)
             var deresult = new Serializer(ClientVersion.Lsp3).DeserializeObject<CompletionItemCapability>(expected);
             deresult.Should().BeEquivalentTo(model);
         }
+
+        [Fact]
+        public void TagSupportTrue()
+        {
+            var deresult = new Serializer(ClientVersion.Lsp3).DeserializeObject<CompletionItemCapability>("{\"tagSupport\":true}");
+            deresult.Should().BeEquivalentTo(new CompletionItemCapability() {
+                TagSupport = new Supports<CompletionItemTagSupportCapability>(true)
+            });
+        }
+
+        [Fact]
+        public void TagSupportObject()
+        {
+            var deresult = new Serializer(ClientVersion.Lsp3).DeserializeObject<CompletionItemCapability>("{\"tagSupport\":{\"valueSet\": [1]}}");
+            deresult.TagSupport.IsSupported.Should().Be(true);
+            deresult.TagSupport.Value.ValueSet.Should().Contain(CompletionItemTag.Deprecated);
+        }
     }
 }

test/Lsp.Tests/Capabilities/Client/PublishDiagnosticsCapabilityTests.cs

@@ -0,0 +1,29 @@
+using FluentAssertions;
+using OmniSharp.Extensions.LanguageServer.Protocol;
+using OmniSharp.Extensions.LanguageServer.Protocol.Client.Capabilities;
+using OmniSharp.Extensions.LanguageServer.Protocol.Models;
+using OmniSharp.Extensions.LanguageServer.Protocol.Serialization;
+using Xunit;
+
+namespace Lsp.Tests.Capabilities.Client
+{
+    public class PublishDiagnosticsCapabilityTests
+    {
+        [Fact]
+        public void TagSupportTrue()
+        {
+            var deresult = new Serializer(ClientVersion.Lsp3).DeserializeObject<PublishDiagnosticsCapability>("{\"tagSupport\":true}");
+            deresult.Should().BeEquivalentTo(new PublishDiagnosticsCapability() {
+                TagSupport = new Supports<PublishDiagnosticsTagSupportCapability>(true)
+            });
+        }
+
+        [Fact]
+        public void TagSupportObject()
+        {
+            var deresult = new Serializer(ClientVersion.Lsp3).DeserializeObject<PublishDiagnosticsCapability>("{\"tagSupport\":{\"valueSet\": [2,1]}}");
+            deresult.TagSupport.IsSupported.Should().Be(true);
+            deresult.TagSupport.Value.ValueSet.Should().ContainInOrder(DiagnosticTag.Deprecated, DiagnosticTag.Unnecessary);
+        }
+    }
+}