Fixes cloning of JsonNode objects

src/Microsoft.OpenApi/Helpers/JsonNodeCloneHelper.cs

@@ -2,6 +2,7 @@
 // Licensed under the MIT license.
 
 using System.Text.Json;
+using System.Text.Json.Nodes;
 using System.Text.Json.Serialization;
 using Json.Schema;
 using Microsoft.OpenApi.Any;
@@ -17,15 +18,24 @@ internal static class JsonNodeCloneHelper
 
         internal static OpenApiAny Clone(OpenApiAny value)
         {
-            var jsonString = Serialize(value);
-            var result = JsonSerializer.Deserialize<OpenApiAny>(jsonString, options);
+            var jsonString = Serialize(value?.Node);
+            if (string.IsNullOrEmpty(jsonString))
+            {
+                return null;
+            }
 
-            return result;
+            var result = JsonSerializer.Deserialize<JsonNode>(jsonString, options);
+            return new OpenApiAny(result);
         }
 
         internal static JsonSchema CloneJsonSchema(JsonSchema schema)
         {
             var jsonString = Serialize(schema);
+            if (string.IsNullOrEmpty(jsonString))
+            {
+                return null;
+            }
+
             var result = JsonSerializer.Deserialize<JsonSchema>(jsonString, options);
             return result;
         }

src/Microsoft.OpenApi/Models/OpenApiExample.cs

@@ -68,10 +68,10 @@ public OpenApiExample(OpenApiExample example)
         {
             Summary = example?.Summary ?? Summary;
             Description = example?.Description ?? Description;
-            Value = example?.Value ?? JsonNodeCloneHelper.Clone(example?.Value);
+            Value = example?.Value != null ? JsonNodeCloneHelper.Clone(example.Value) : null;
             ExternalValue = example?.ExternalValue ?? ExternalValue;
             Extensions = example?.Extensions != null ? new Dictionary<string, IOpenApiExtension>(example.Extensions) : null;
-            Reference = example?.Reference != null ? new(example?.Reference) : null;
+            Reference = example?.Reference != null ? new(example.Reference) : null;
             UnresolvedReference = example?.UnresolvedReference ?? UnresolvedReference;
         }
 

src/Microsoft.OpenApi/Models/OpenApiHeader.cs

@@ -114,8 +114,8 @@ public OpenApiHeader(OpenApiHeader header)
             Style = header?.Style ?? Style;
             Explode = header?.Explode ?? Explode;
             AllowReserved = header?.AllowReserved ?? AllowReserved;
-            Schema = header?.Schema != null ? JsonNodeCloneHelper.CloneJsonSchema(header?.Schema) : null;
-            Example = header?.Example != null ? JsonNodeCloneHelper.Clone(header?.Example) : null;
+            Schema = header?.Schema != null ? JsonNodeCloneHelper.CloneJsonSchema(header.Schema) : null;
+            Example = header?.Example != null ? JsonNodeCloneHelper.Clone(header.Example) : null;
             Examples = header?.Examples != null ? new Dictionary<string, OpenApiExample>(header.Examples) : null;
             Content = header?.Content != null ? new Dictionary<string, OpenApiMediaType>(header.Content) : null;
             Extensions = header?.Extensions != null ? new Dictionary<string, IOpenApiExtension>(header.Extensions) : null;

src/Microsoft.OpenApi/Models/OpenApiMediaType.cs

@@ -62,8 +62,8 @@ public OpenApiMediaType() { }
         /// </summary>
         public OpenApiMediaType(OpenApiMediaType mediaType)
         {
-            _schema = JsonNodeCloneHelper.CloneJsonSchema(mediaType?.Schema);
-            Example = JsonNodeCloneHelper.Clone(mediaType?.Example);
+            Schema = mediaType?.Schema != null ? JsonNodeCloneHelper.CloneJsonSchema(mediaType.Schema) : null;
+            Example = mediaType?.Example != null ? JsonNodeCloneHelper.Clone(mediaType.Example) : null;
             Examples = mediaType?.Examples != null ? new Dictionary<string, OpenApiExample>(mediaType.Examples) : null;
             Encoding = mediaType?.Encoding != null ? new Dictionary<string, OpenApiEncoding>(mediaType.Encoding) : null;
             Extensions = mediaType?.Extensions != null ? new Dictionary<string, IOpenApiExtension>(mediaType.Extensions) : null;

src/Microsoft.OpenApi/Models/OpenApiParameter.cs

@@ -1,4 +1,4 @@
-// Copyright (c) Microsoft Corporation. All rights reserved.
+// Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT license.
 
 using System;
@@ -168,9 +168,9 @@ public OpenApiParameter(OpenApiParameter parameter)
             Style = parameter?.Style ?? Style;
             Explode = parameter?.Explode ?? Explode;
             AllowReserved = parameter?.AllowReserved ?? AllowReserved;
-            Schema = parameter?.Schema != null ? JsonNodeCloneHelper.CloneJsonSchema(parameter?.Schema) : null;
+            Schema = parameter?.Schema != null ? JsonNodeCloneHelper.CloneJsonSchema(parameter.Schema) : null;
             Examples = parameter?.Examples != null ? new Dictionary<string, OpenApiExample>(parameter.Examples) : null;
-            Example = parameter?.Example != null ? JsonNodeCloneHelper.Clone(parameter?.Example) : null;
+            Example = parameter?.Example != null ? JsonNodeCloneHelper.Clone(parameter.Example) : null;
             Content = parameter?.Content != null ? new Dictionary<string, OpenApiMediaType>(parameter.Content) : null;
             Extensions = parameter?.Extensions != null ? new Dictionary<string, IOpenApiExtension>(parameter.Extensions) : null;
             AllowEmptyValue = parameter?.AllowEmptyValue ?? AllowEmptyValue;

src/Microsoft.OpenApi/Models/References/OpenApiExampleReference.cs

@@ -125,7 +125,7 @@ public override void SerializeAsV31(IOpenApiWriter writer)
         private void SerializeInternal(IOpenApiWriter writer,
             Action<IOpenApiWriter, IOpenApiReferenceable> action)
         {
-            Utils.CheckArgumentNull(writer);;
+            Utils.CheckArgumentNull(writer);
             action(writer, Target);
         }
     }

src/Microsoft.OpenApi/Reader/Services/OpenApiRemoteReferenceCollector.cs

@@ -1,7 +1,6 @@
-// Copyright (c) Microsoft Corporation. All rights reserved.
+// Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT license.
 
-using System;
 using System.Collections.Generic;
 using Microsoft.OpenApi.Interfaces;
 using Microsoft.OpenApi.Models;

test/Microsoft.OpenApi.Tests/Models/References/OpenApiExampleReferenceTests.cs

@@ -133,7 +133,7 @@ public OpenApiExampleReferenceTests()
 
         [Fact]
         public void ExampleReferenceResolutionWorks()
-        {
+         {
             // Assert
             Assert.NotNull(_localExampleReference.Value);
             Assert.Equal("[{\"id\":1,\"name\":\"John Doe\"}]", _localExampleReference.Value.Node.ToJsonString());