Added test for null cases as well

Author: david-driscoll

sample/SampleServer/SampleServer.csproj

@@ -1,4 +1,4 @@
-la<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
     <PropertyGroup>
         <OutputType>Exe</OutputType>

src/JsonRpc/Serialization/Converters/EnumLikeStringConverter.cs

@@ -16,7 +16,8 @@ JsonSerializer serializer
             ( reader.TokenType, Nullable.GetUnderlyingType(objectType) ) switch {
                 (JsonToken.String, null)         => (IEnumLikeString) Activator.CreateInstance(objectType, (string) reader.Value),
                 (JsonToken.String, { } realType) => (IEnumLikeString) Activator.CreateInstance(realType, (string) reader.Value),
-                _                                => (IEnumLikeString) Activator.CreateInstance(objectType, null)
+                (_, { })                         => (IEnumLikeString) Activator.CreateInstance(objectType, null),
+                _                                => null
             };
 
         public override bool CanRead => true;

test/Dap.Tests/EnumLikeConverterTests.cs

@@ -23,8 +23,14 @@ public void PathFormat_Should_Be_Serializable()
         [Fact]
         public void PathFormat_Should_Be_Deserializable()
         {
-            Action a = () => new DapSerializer().DeserializeObject<InitializeRequestArguments>("{\"pathformat\": \"Uri\"}");
-            a.Should().NotThrow();
+            Func<InitializeRequestArguments> a = () => new DapSerializer().DeserializeObject<InitializeRequestArguments>("{\"pathformat\": \"Uri\"}");
+            a.Should().NotThrow().Subject.PathFormat.Should().NotBeNull();
+        }
+        [Fact]
+        public void PathFormat_Should_Be_Deserializable_When_Null()
+        {
+            var a = new DapSerializer().DeserializeObject<InitializeRequestArguments>("{\"pathformat\":null}");
+            a.PathFormat.Should().BeNull();
         }
     }
 }