Fix tags serialization bug

src/Microsoft.OpenApi.Readers/OpenApiYamlReader.cs

@@ -77,7 +77,7 @@ static JsonNode LoadJsonNodesFromYamlDocument(TextReader input)
         {
             var yamlStream = new YamlStream();
             yamlStream.Load(input);
-            var yamlDocument = yamlStream.Documents.First();
+            var yamlDocument = yamlStream.Documents[0];
             return yamlDocument.ToJsonNode();
         }
 

src/Microsoft.OpenApi/Models/OpenApiTag.cs

@@ -55,56 +55,31 @@
         {
             Name = tag?.Name ?? Name;
             Description = tag?.Description ?? Description;
-            ExternalDocs = tag?.ExternalDocs != null ? new(tag?.ExternalDocs) : null;
+            ExternalDocs = tag?.ExternalDocs != null ? new(tag.ExternalDocs) : null;
             Extensions = tag?.Extensions != null ? new Dictionary<string, IOpenApiExtension>(tag.Extensions) : null;
             UnresolvedReference = tag?.UnresolvedReference ?? UnresolvedReference;
-            Reference = tag?.Reference != null ? new(tag?.Reference) : null;
+            Reference = tag?.Reference != null ? new(tag.Reference) : null;
         }
 
         /// <summary>
         /// Serialize <see cref="OpenApiTag"/> to Open Api v3.1
         /// </summary>
-        public virtual void SerializeAsV31(IOpenApiWriter writer)
+        public virtual void SerializeAsV31(IOpenApiWriter writer) 
         {
-            SerializeInternal(writer, (writer, element) => element.SerializeAsV31(writer));
-        }
-
-        /// <summary>
-        /// Serialize <see cref="OpenApiTag"/> to Open Api v3.0
-        /// </summary>
-        public virtual void SerializeAsV3(IOpenApiWriter writer)
-        {
-            SerializeInternal(writer, (writer, element) => element.SerializeAsV3(writer));
-        }
-
-        /// <summary>
-        /// Serialize <see cref="OpenApiTag"/> to Open Api v3.0
-        /// </summary>
-        private void SerializeInternal(IOpenApiWriter writer, Action<IOpenApiWriter, IOpenApiSerializable> callback)
-        {
-            Utils.CheckArgumentNull(writer);
-            writer.WriteValue(Name);
-        }
-
-        /// <summary>
-        /// Serialize to OpenAPI V3 document without using reference.
-        /// </summary>
-        public virtual void SerializeAsV31WithoutReference(IOpenApiWriter writer) 
-        {
-            SerializeInternalWithoutReference(writer, OpenApiSpecVersion.OpenApi3_1,
+            SerializeInternal(writer, OpenApiSpecVersion.OpenApi3_1,
                 (writer, element) => element.SerializeAsV31(writer));
         }
 
         /// <summary>
-        /// Serialize to OpenAPI V3 document without using reference.
+        /// Serialize <see cref="OpenApiTag"/> to Open Api v3.0
         /// </summary>
-        public virtual void SerializeAsV3WithoutReference(IOpenApiWriter writer) 
+        public virtual void SerializeAsV3(IOpenApiWriter writer) 
         {
-            SerializeInternalWithoutReference(writer, OpenApiSpecVersion.OpenApi3_0,
+            SerializeInternal(writer, OpenApiSpecVersion.OpenApi3_0,
                 (writer, element) => element.SerializeAsV3(writer));
         }
 
-        internal virtual void SerializeInternalWithoutReference(IOpenApiWriter writer, OpenApiSpecVersion version, 
+        internal virtual void SerializeInternal(IOpenApiWriter writer, OpenApiSpecVersion version, 
             Action<IOpenApiWriter, IOpenApiSerializable> callback)
         {
             writer.WriteStartObject();
@@ -128,15 +103,6 @@
         /// Serialize <see cref="OpenApiTag"/> to Open Api v2.0
         /// </summary>
         public virtual void SerializeAsV2(IOpenApiWriter writer)
-        {
-            Utils.CheckArgumentNull(writer);
-            writer.WriteValue(Name);
-        }
-
-        /// <summary>
-        /// Serialize to OpenAPI V2 document without using reference.
-        /// </summary>
-        public void SerializeAsV2WithoutReference(IOpenApiWriter writer)
         {
             writer.WriteStartObject();
 

test/Microsoft.OpenApi.Tests/Models/OpenApiDocumentTests.cs

@@ -992,7 +992,7 @@ public OpenApiDocumentTests()
                                         {
                                             ["my-extension"] = new OpenApiAny(4)
                                         }
-                                    },                                        
+                                    },
                                     Extensions = new Dictionary<string, IOpenApiExtension>
                                     {
                                         ["my-extension"] = new OpenApiAny(4),
@@ -2072,5 +2072,59 @@ public void SerializeDocWithDollarIdInDollarRefSucceeds()
             var actual = doc.SerializeAsYaml(OpenApiSpecVersion.OpenApi3_1);
             actual.MakeLineBreaksEnvironmentNeutral().Should().BeEquivalentTo(expected.MakeLineBreaksEnvironmentNeutral());
         }
+
+        [Fact]
+        public void SerializeDocumentTagsWithMultipleExtensionsWorks()
+        {
+            var expected = @"{
+  ""openapi"": ""3.0.4"",
+  ""info"": {
+    ""title"": ""Test"",
+    ""version"": ""1.0.0""
+  },
+  ""paths"": { },
+  ""tags"": [
+    {
+      ""name"": ""tag1"",
+      ""x-tag1"": ""tag1""
+    },
+    {
+      ""name"": ""tag2"",
+      ""x-tag2"": ""tag2""
+    }
+  ]
+}";
+            var doc = new OpenApiDocument
+            {
+                Info = new OpenApiInfo
+                {
+                    Title = "Test",
+                    Version = "1.0.0"
+                },
+                Paths = new OpenApiPaths(),
+                Tags = new List<OpenApiTag>
+                {
+                    new OpenApiTag
+                    {
+                        Name = "tag1",
+                        Extensions = new Dictionary<string, IOpenApiExtension>
+                        {
+                            ["x-tag1"] = new OpenApiAny("tag1")
+                        }
+                    },
+                    new OpenApiTag
+                    {
+                        Name = "tag2",
+                        Extensions = new Dictionary<string, IOpenApiExtension>
+                        {
+                            ["x-tag2"] = new OpenApiAny("tag2")
+                        }
+                    }
+                }
+            };
+
+            var actual = doc.SerializeAsJson(OpenApiSpecVersion.OpenApi3_0);
+            actual.MakeLineBreaksEnvironmentNeutral().Should().BeEquivalentTo(expected.MakeLineBreaksEnvironmentNeutral());
+        }
     }
 }

test/Microsoft.OpenApi.Tests/Models/OpenApiOperationTests.cs

@@ -89,11 +89,6 @@ public class OpenApiOperationTests
         {
             Tags = new List<OpenApiTag>
             {
-                new()
-                {
-                    Name = "tagName1",
-                    Description = "tagDescription1",
-                },
                 new OpenApiTagReference("tagId1", null)
             },
             Summary = "summary1",
@@ -360,7 +355,6 @@ public void SerializeAdvancedOperationWithTagAndSecurityAsV3JsonWorks()
                 """
                 {
                   "tags": [
-                    "tagName1",
                     "tagId1"
                   ],
                   "summary": "summary1",
@@ -669,7 +663,6 @@ public void SerializeAdvancedOperationWithTagAndSecurityAsV2JsonWorks()
                 """
                 {
                   "tags": [
-                    "tagName1",
                     "tagId1"
                   ],
                   "summary": "summary1",

test/Microsoft.OpenApi.Tests/Models/OpenApiTagTests.SerializeAdvancedTagAsV2JsonWorksAsync_produceTerseOutput=False.verified.txt

@@ -1 +1,9 @@
-"pet"
+{
+  "name": "pet",
+  "description": "Pets operations",
+  "externalDocs": {
+    "description": "Find more info here",
+    "url": "https://example.com"
+  },
+  "x-tag-extension": null
+}

test/Microsoft.OpenApi.Tests/Models/OpenApiTagTests.SerializeAdvancedTagAsV2JsonWorksAsync_produceTerseOutput=True.verified.txt

@@ -1 +1 @@
-"pet"
+{"name":"pet","description":"Pets operations","externalDocs":{"description":"Find more info here","url":"https://example.com"},"x-tag-extension":null}

test/Microsoft.OpenApi.Tests/Models/OpenApiTagTests.SerializeAdvancedTagAsV3JsonWorksAsync_produceTerseOutput=False.verified.txt

@@ -1 +1,9 @@
-"pet"
+{
+  "name": "pet",
+  "description": "Pets operations",
+  "externalDocs": {
+    "description": "Find more info here",
+    "url": "https://example.com"
+  },
+  "x-tag-extension": null
+}

test/Microsoft.OpenApi.Tests/Models/OpenApiTagTests.SerializeAdvancedTagAsV3JsonWorksAsync_produceTerseOutput=True.verified.txt

@@ -1 +1 @@
-"pet"
+{"name":"pet","description":"Pets operations","externalDocs":{"description":"Find more info here","url":"https://example.com"},"x-tag-extension":null}

test/Microsoft.OpenApi.Tests/Models/OpenApiTagTests.cs

@@ -8,6 +8,7 @@
 using FluentAssertions;
 using Microsoft.OpenApi.Interfaces;
 using Microsoft.OpenApi.Models;
+using Microsoft.OpenApi.Models.References;
 using Microsoft.OpenApi.Writers;
 using VerifyXunit;
 using Xunit;
@@ -17,9 +18,9 @@ namespace Microsoft.OpenApi.Tests.Models
     [Collection("DefaultSettings")]
     public class OpenApiTagTests
     {
-        public static OpenApiTag BasicTag = new();
+        public static readonly OpenApiTag BasicTag = new();
 
-        public static OpenApiTag AdvancedTag = new()
+        public static readonly OpenApiTag AdvancedTag = new()
         {
             Name = "pet",
             Description = "Pets operations",
@@ -30,21 +31,7 @@ public class OpenApiTagTests
             }
         };
 
-        public static OpenApiTag ReferencedTag = new()
-        {
-            Name = "pet",
-            Description = "Pets operations",
-            ExternalDocs = OpenApiExternalDocsTests.AdvanceExDocs,
-            Extensions = new Dictionary<string, IOpenApiExtension>
-            {
-                {"x-tag-extension", null}
-            },
-            Reference = new()
-            {
-                Type = ReferenceType.Tag,
-                Id = "pet"
-            }
-        };
+        public static OpenApiTag ReferencedTag = new OpenApiTagReference("pet", null);
 
         [Theory]
         [InlineData(true)]
@@ -56,7 +43,7 @@ public async Task SerializeBasicTagAsV3JsonWithoutReferenceWorksAsync(bool produ
             var writer = new OpenApiJsonWriter(outputStringWriter, new() { Terse = produceTerseOutput });
 
             // Act
-            BasicTag.SerializeAsV3WithoutReference(writer);
+            BasicTag.SerializeAsV3(writer);
             writer.Flush();
 
             // Assert
@@ -73,7 +60,7 @@ public async Task SerializeBasicTagAsV2JsonWithoutReferenceWorksAsync(bool produ
             var writer = new OpenApiJsonWriter(outputStringWriter, new() { Terse = produceTerseOutput });
 
             // Act
-            BasicTag.SerializeAsV2WithoutReference(writer);
+            BasicTag.SerializeAsV2(writer);
             writer.Flush();
 
             // Assert
@@ -89,7 +76,7 @@ public void SerializeBasicTagAsV3YamlWithoutReferenceWorks()
             var expected = "{ }";
 
             // Act
-            BasicTag.SerializeAsV3WithoutReference(writer);
+            BasicTag.SerializeAsV3(writer);
             var actual = outputStringWriter.GetStringBuilder().ToString();
 
             // Assert
@@ -107,7 +94,7 @@ public void SerializeBasicTagAsV2YamlWithoutReferenceWorks()
             var expected = "{ }";
 
             // Act
-            BasicTag.SerializeAsV2WithoutReference(writer);
+            BasicTag.SerializeAsV2(writer);
             writer.Flush();
             var actual = outputStringWriter.GetStringBuilder().ToString();
 
@@ -117,40 +104,6 @@ public void SerializeBasicTagAsV2YamlWithoutReferenceWorks()
             actual.Should().Be(expected);
         }
 
-        [Theory]
-        [InlineData(true)]
-        [InlineData(false)]
-        public async Task SerializeAdvancedTagAsV3JsonWithoutReferenceWorksAsync(bool produceTerseOutput)
-        {
-            // Arrange
-            var outputStringWriter = new StringWriter(CultureInfo.InvariantCulture);
-            var writer = new OpenApiJsonWriter(outputStringWriter, new() { Terse = produceTerseOutput });
-
-            // Act
-            AdvancedTag.SerializeAsV3WithoutReference(writer);
-            writer.Flush();
-
-            // Assert
-            await Verifier.Verify(outputStringWriter).UseParameters(produceTerseOutput);
-        }
-
-        [Theory]
-        [InlineData(true)]
-        [InlineData(false)]
-        public async Task SerializeAdvancedTagAsV2JsonWithoutReferenceWorksAsync(bool produceTerseOutput)
-        {
-            // Arrange
-            var outputStringWriter = new StringWriter(CultureInfo.InvariantCulture);
-            var writer = new OpenApiJsonWriter(outputStringWriter, new() { Terse = produceTerseOutput });
-
-            // Act
-            AdvancedTag.SerializeAsV2WithoutReference(writer);
-            writer.Flush();
-
-            // Assert
-            await Verifier.Verify(outputStringWriter).UseParameters(produceTerseOutput);
-        }
-
         [Fact]
         public void SerializeAdvancedTagAsV3YamlWithoutReferenceWorks()
         {
@@ -168,7 +121,7 @@ public void SerializeAdvancedTagAsV3YamlWithoutReferenceWorks()
                 """;
 
             // Act
-            AdvancedTag.SerializeAsV3WithoutReference(writer);
+            AdvancedTag.SerializeAsV3(writer);
             writer.Flush();
             var actual = outputStringWriter.GetStringBuilder().ToString();
 
@@ -195,7 +148,7 @@ public void SerializeAdvancedTagAsV2YamlWithoutReferenceWorks()
                 """;
 
             // Act
-            AdvancedTag.SerializeAsV2WithoutReference(writer);
+            AdvancedTag.SerializeAsV2(writer);
             writer.Flush();
             var actual = outputStringWriter.GetStringBuilder().ToString();
 
@@ -246,7 +199,12 @@ public void SerializeAdvancedTagAsV3YamlWorks()
             var outputStringWriter = new StringWriter(CultureInfo.InvariantCulture);
             var writer = new OpenApiYamlWriter(outputStringWriter);
 
-            var expected = @" pet";
+            var expected = @"name: pet
+description: Pets operations
+externalDocs:
+  description: Find more info here
+  url: https://example.com
+x-tag-extension:";
 
             // Act
             AdvancedTag.SerializeAsV3(writer);
@@ -266,7 +224,12 @@ public void SerializeAdvancedTagAsV2YamlWorks()
             var outputStringWriter = new StringWriter(CultureInfo.InvariantCulture);
             var writer = new OpenApiYamlWriter(outputStringWriter);
 
-            var expected = @" pet";
+            var expected = @"name: pet
+description: Pets operations
+externalDocs:
+  description: Find more info here
+  url: https://example.com
+x-tag-extension:";
 
             // Act
             AdvancedTag.SerializeAsV2(writer);