LSP Protocol: Support Uri in SumType

Author: mhutch

src/LanguageServer/Microsoft.CodeAnalysis.LanguageServer.UnitTests/LspFileChangeWatcherTests.cs

@@ -66,7 +66,7 @@ public async Task CreatingDirectoryWatchRequestsDirectoryWatch()
 
         var watcher = GetSingleFileWatcher(dynamicCapabilitiesRpcTarget);
 
-        Assert.Equal(tempDirectory.Path, watcher.GlobPattern.Second.BaseUri.First.LocalPath);
+        Assert.Equal(tempDirectory.Path, watcher.GlobPattern.Second.BaseUri.Second.LocalPath);
         Assert.Equal("**/*", watcher.GlobPattern.Second.Pattern);
 
         // Get rid of the registration and it should be gone again
@@ -98,7 +98,7 @@ public async Task CreatingFileWatchRequestsFileWatch()
 
         var watcher = GetSingleFileWatcher(dynamicCapabilitiesRpcTarget);
 
-        Assert.Equal("Z:\\", watcher.GlobPattern.Second.BaseUri.First.LocalPath);
+        Assert.Equal("Z:\\", watcher.GlobPattern.Second.BaseUri.Second.LocalPath);
         Assert.Equal("SingleFile.txt", watcher.GlobPattern.Second.Pattern);
 
         // Get rid of the registration and it should be gone again

src/LanguageServer/Protocol/Protocol/Converters/SumConverter.cs

@@ -249,7 +249,7 @@ public override T Read(ref Utf8JsonReader reader, Type objectType, JsonSerialize
             }
         }
 
-        throw new JsonException(LanguageServerProtocolResources.NoSumTypeMatch);
+        throw new JsonException($"No sum type match for {objectType}");
     }
 
     /// <inheritdoc/>
@@ -259,6 +259,13 @@ public override void Write(Utf8JsonWriter writer, T value, JsonSerializerOptions
 
         var sumValue = value.Value;
 
+        // behavior from DocumentUriConverter
+        if (sumValue is Uri)
+        {
+            writer.WriteStringValue(sumValue.ToString());
+            return;
+        }
+
         if (sumValue != null)
         {
             JsonSerializer.Serialize(writer, sumValue, options);
@@ -288,6 +295,7 @@ private static bool IsTokenCompatibleWithType(ref Utf8JsonReader reader, SumConv
                 break;
             case JsonTokenType.String:
                 isCompatible = unionTypeInfo.Type == typeof(string) ||
+                               unionTypeInfo.Type == typeof(Uri) ||
                                typeof(IStringEnum).IsAssignableFrom(unionTypeInfo.Type);
                 break;
         }

src/LanguageServer/Protocol/Protocol/FileOperations/RelativePattern.cs

@@ -21,7 +21,7 @@ internal class RelativePattern
     /// </summary>
     [JsonPropertyName("baseUri")]
     [JsonRequired]
-    public SumType<Uri, WorkspaceFolder> BaseUri { get; init; }
+    public SumType<WorkspaceFolder, Uri> BaseUri { get; init; }
 
     /// <summary>
     /// The actual glob pattern. See <see href="https://microsoft.github.io/language-server-protocol/specifications/specification-current/#pattern">Glob Pattern</see> for more detail.