[ASPNETCORE] Fix having two "?" when not required and nullable = true (#19062)

* fix #18005: Prevent adding 2 times the "?" when not required and nullable = true

* fix #18005: Fix carriage return diff

* update samples

---------

Co-authored-by: William Cheng <wing328hk@gmail.com>

modules/openapi-generator/src/main/resources/aspnetcore/3.0/model.mustache

@@ -77,7 +77,7 @@ namespace {{modelPackage}}
         public {{{datatypeWithEnum}}}{{#isNullable}}?{{/isNullable}} {{name}} { get; set; }{{#defaultValue}} = {{{.}}};{{/defaultValue}}
         {{/isEnum}}
         {{^isEnum}}
-        public {{{dataType}}}{{#nullableReferenceTypes}}{{^isContainer}}{{^required}}?{{/required}}{{/isContainer}}{{/nullableReferenceTypes}} {{name}} { get; set; }{{#defaultValue}} = {{{.}}};{{/defaultValue}}
+        public {{{dataType}}}{{#nullableReferenceTypes}}{{^isContainer}}{{^required}}{{^isNullable}}?{{/isNullable}}{{/required}}{{/isContainer}}{{/nullableReferenceTypes}} {{name}} { get; set; }{{#defaultValue}} = {{{.}}};{{/defaultValue}}
         {{/isEnum}}
         {{^-last}}
 

modules/openapi-generator/src/test/resources/3_0/aspnetcore/petstore.yaml

@@ -594,6 +594,20 @@ paths:
       responses:
         default:
           description: successful operation
+  /fake/nullable_example_test:
+    get:
+      tags:
+        - fake
+      summary: Fake endpoint to test nullable example (object)
+      description: ''
+      operationId: fake_nullable_example_test
+      responses:
+        '200':
+          description: Successful operation
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/TestNullable'
 externalDocs:
   description: Find out more about Swagger
   url: 'http://swagger.io'
@@ -637,6 +651,14 @@ components:
       enum:
         - A
         - B
+    TestNullable:
+      type: object
+      properties:
+        name:
+          type: string
+        nullableName:
+          type: string
+          nullable: true
     Order:
       title: Pet Order
       description: An order for a pets from the pet store

samples/server/petstore/aspnetcore-3.0/.openapi-generator/FILES

@@ -24,6 +24,7 @@ src/Org.OpenAPITools/Models/Order.cs
 src/Org.OpenAPITools/Models/Pet.cs
 src/Org.OpenAPITools/Models/Tag.cs
 src/Org.OpenAPITools/Models/TestEnum.cs
+src/Org.OpenAPITools/Models/TestNullable.cs
 src/Org.OpenAPITools/Models/User.cs
 src/Org.OpenAPITools/OpenApi/TypeExtensions.cs
 src/Org.OpenAPITools/Program.cs

samples/server/petstore/aspnetcore-3.0/src/Org.OpenAPITools/Controllers/FakeApi.cs

@@ -28,6 +28,30 @@ namespace Org.OpenAPITools.Controllers
     [ApiController]
     public class FakeApiController : ControllerBase
     { 
+        /// <summary>
+        /// Fake endpoint to test nullable example (object)
+        /// </summary>
+        /// <response code="200">Successful operation</response>
+        [HttpGet]
+        [Route("/v2/fake/nullable_example_test")]
+        [ValidateModelState]
+        [SwaggerOperation("FakeNullableExampleTest")]
+        [SwaggerResponse(statusCode: 200, type: typeof(TestNullable), description: "Successful operation")]
+        public virtual IActionResult FakeNullableExampleTest()
+        {
+
+            //TODO: Uncomment the next line to return response 200 or use other options such as return this.NotFound(), return this.BadRequest(..), ...
+            // return StatusCode(200, default(TestNullable));
+            string exampleJson = null;
+            exampleJson = "{\n  \"nullableName\" : \"nullableName\",\n  \"name\" : \"name\"\n}";
+            
+            var example = exampleJson != null
+            ? JsonConvert.DeserializeObject<TestNullable>(exampleJson)
+            : default(TestNullable);
+            //TODO: Change the data returned
+            return new ObjectResult(example);
+        }
+
         /// <summary>
         /// fake endpoint to test parameter example (object)
         /// </summary>

samples/server/petstore/aspnetcore-3.0/src/Org.OpenAPITools/Models/TestNullable.cs

@@ -0,0 +1,133 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ * Generated by: https://openapi-generator.tech
+ */
+
+using System;
+using System.Linq;
+using System.Text;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.ComponentModel.DataAnnotations;
+using System.Runtime.Serialization;
+using Newtonsoft.Json;
+using Org.OpenAPITools.Converters;
+
+namespace Org.OpenAPITools.Models
+{ 
+    /// <summary>
+    /// 
+    /// </summary>
+    [DataContract]
+    public partial class TestNullable : IEquatable<TestNullable>
+    {
+        /// <summary>
+        /// Gets or Sets Name
+        /// </summary>
+        [DataMember(Name="name", EmitDefaultValue=false)]
+        public string Name { get; set; }
+
+        /// <summary>
+        /// Gets or Sets NullableName
+        /// </summary>
+        [DataMember(Name="nullableName", EmitDefaultValue=true)]
+        public string NullableName { get; set; }
+
+        /// <summary>
+        /// Returns the string presentation of the object
+        /// </summary>
+        /// <returns>String presentation of the object</returns>
+        public override string ToString()
+        {
+            var sb = new StringBuilder();
+            sb.Append("class TestNullable {\n");
+            sb.Append("  Name: ").Append(Name).Append("\n");
+            sb.Append("  NullableName: ").Append(NullableName).Append("\n");
+            sb.Append("}\n");
+            return sb.ToString();
+        }
+
+        /// <summary>
+        /// Returns the JSON string presentation of the object
+        /// </summary>
+        /// <returns>JSON string presentation of the object</returns>
+        public string ToJson()
+        {
+            return JsonConvert.SerializeObject(this, Formatting.Indented);
+        }
+
+        /// <summary>
+        /// Returns true if objects are equal
+        /// </summary>
+        /// <param name="obj">Object to be compared</param>
+        /// <returns>Boolean</returns>
+        public override bool Equals(object obj)
+        {
+            if (obj is null) return false;
+            if (ReferenceEquals(this, obj)) return true;
+            return obj.GetType() == GetType() && Equals((TestNullable)obj);
+        }
+
+        /// <summary>
+        /// Returns true if TestNullable instances are equal
+        /// </summary>
+        /// <param name="other">Instance of TestNullable to be compared</param>
+        /// <returns>Boolean</returns>
+        public bool Equals(TestNullable other)
+        {
+            if (other is null) return false;
+            if (ReferenceEquals(this, other)) return true;
+
+            return 
+                (
+                    Name == other.Name ||
+                    Name != null &&
+                    Name.Equals(other.Name)
+                ) && 
+                (
+                    NullableName == other.NullableName ||
+                    NullableName != null &&
+                    NullableName.Equals(other.NullableName)
+                );
+        }
+
+        /// <summary>
+        /// Gets the hash code
+        /// </summary>
+        /// <returns>Hash code</returns>
+        public override int GetHashCode()
+        {
+            unchecked // Overflow is fine, just wrap
+            {
+                var hashCode = 41;
+                // Suitable nullity checks etc, of course :)
+                    if (Name != null)
+                    hashCode = hashCode * 59 + Name.GetHashCode();
+                    if (NullableName != null)
+                    hashCode = hashCode * 59 + NullableName.GetHashCode();
+                return hashCode;
+            }
+        }
+
+        #region Operators
+        #pragma warning disable 1591
+
+        public static bool operator ==(TestNullable left, TestNullable right)
+        {
+            return Equals(left, right);
+        }
+
+        public static bool operator !=(TestNullable left, TestNullable right)
+        {
+            return !Equals(left, right);
+        }
+
+        #pragma warning restore 1591
+        #endregion Operators
+    }
+}

samples/server/petstore/aspnetcore-3.0/src/Org.OpenAPITools/wwwroot/openapi-original.json

@@ -812,6 +812,26 @@
         "summary" : "fake endpoint to test parameter example (object)",
         "tags" : [ "fake" ]
       }
+    },
+    "/fake/nullable_example_test" : {
+      "get" : {
+        "description" : "",
+        "operationId" : "fake_nullable_example_test",
+        "responses" : {
+          "200" : {
+            "content" : {
+              "application/json" : {
+                "schema" : {
+                  "$ref" : "#/components/schemas/TestNullable"
+                }
+              }
+            },
+            "description" : "Successful operation"
+          }
+        },
+        "summary" : "Fake endpoint to test nullable example (object)",
+        "tags" : [ "fake" ]
+      }
     }
   },
   "components" : {
@@ -852,6 +872,22 @@
         "enum" : [ "A", "B" ],
         "type" : "string"
       },
+      "TestNullable" : {
+        "example" : {
+          "nullableName" : "nullableName",
+          "name" : "name"
+        },
+        "properties" : {
+          "name" : {
+            "type" : "string"
+          },
+          "nullableName" : {
+            "nullable" : true,
+            "type" : "string"
+          }
+        },
+        "type" : "object"
+      },
       "Order" : {
         "description" : "An order for a pets from the pet store",
         "example" : {

samples/server/petstore/aspnetcore-3.1/.openapi-generator/FILES

@@ -24,6 +24,7 @@ src/Org.OpenAPITools/Models/Order.cs
 src/Org.OpenAPITools/Models/Pet.cs
 src/Org.OpenAPITools/Models/Tag.cs
 src/Org.OpenAPITools/Models/TestEnum.cs
+src/Org.OpenAPITools/Models/TestNullable.cs
 src/Org.OpenAPITools/Models/User.cs
 src/Org.OpenAPITools/OpenApi/TypeExtensions.cs
 src/Org.OpenAPITools/Program.cs

samples/server/petstore/aspnetcore-3.1/src/Org.OpenAPITools/Controllers/FakeApi.cs

@@ -28,6 +28,30 @@ namespace Org.OpenAPITools.Controllers
     [ApiController]
     public class FakeApiController : ControllerBase
     { 
+        /// <summary>
+        /// Fake endpoint to test nullable example (object)
+        /// </summary>
+        /// <response code="200">Successful operation</response>
+        [HttpGet]
+        [Route("/v2/fake/nullable_example_test")]
+        [ValidateModelState]
+        [SwaggerOperation("FakeNullableExampleTest")]
+        [SwaggerResponse(statusCode: 200, type: typeof(TestNullable), description: "Successful operation")]
+        public virtual IActionResult FakeNullableExampleTest()
+        {
+
+            //TODO: Uncomment the next line to return response 200 or use other options such as return this.NotFound(), return this.BadRequest(..), ...
+            // return StatusCode(200, default(TestNullable));
+            string exampleJson = null;
+            exampleJson = "{\n  \"nullableName\" : \"nullableName\",\n  \"name\" : \"name\"\n}";
+            
+            var example = exampleJson != null
+            ? JsonConvert.DeserializeObject<TestNullable>(exampleJson)
+            : default(TestNullable);
+            //TODO: Change the data returned
+            return new ObjectResult(example);
+        }
+
         /// <summary>
         /// fake endpoint to test parameter example (object)
         /// </summary>

samples/server/petstore/aspnetcore-3.1/src/Org.OpenAPITools/Models/TestNullable.cs

@@ -0,0 +1,133 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ * Generated by: https://openapi-generator.tech
+ */
+
+using System;
+using System.Linq;
+using System.Text;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.ComponentModel.DataAnnotations;
+using System.Runtime.Serialization;
+using Newtonsoft.Json;
+using Org.OpenAPITools.Converters;
+
+namespace Org.OpenAPITools.Models
+{ 
+    /// <summary>
+    /// 
+    /// </summary>
+    [DataContract]
+    public partial class TestNullable : IEquatable<TestNullable>
+    {
+        /// <summary>
+        /// Gets or Sets Name
+        /// </summary>
+        [DataMember(Name="name", EmitDefaultValue=false)]
+        public string Name { get; set; }
+
+        /// <summary>
+        /// Gets or Sets NullableName
+        /// </summary>
+        [DataMember(Name="nullableName", EmitDefaultValue=true)]
+        public string NullableName { get; set; }
+
+        /// <summary>
+        /// Returns the string presentation of the object
+        /// </summary>
+        /// <returns>String presentation of the object</returns>
+        public override string ToString()
+        {
+            var sb = new StringBuilder();
+            sb.Append("class TestNullable {\n");
+            sb.Append("  Name: ").Append(Name).Append("\n");
+            sb.Append("  NullableName: ").Append(NullableName).Append("\n");
+            sb.Append("}\n");
+            return sb.ToString();
+        }
+
+        /// <summary>
+        /// Returns the JSON string presentation of the object
+        /// </summary>
+        /// <returns>JSON string presentation of the object</returns>
+        public string ToJson()
+        {
+            return JsonConvert.SerializeObject(this, Formatting.Indented);
+        }
+
+        /// <summary>
+        /// Returns true if objects are equal
+        /// </summary>
+        /// <param name="obj">Object to be compared</param>
+        /// <returns>Boolean</returns>
+        public override bool Equals(object obj)
+        {
+            if (obj is null) return false;
+            if (ReferenceEquals(this, obj)) return true;
+            return obj.GetType() == GetType() && Equals((TestNullable)obj);
+        }
+
+        /// <summary>
+        /// Returns true if TestNullable instances are equal
+        /// </summary>
+        /// <param name="other">Instance of TestNullable to be compared</param>
+        /// <returns>Boolean</returns>
+        public bool Equals(TestNullable other)
+        {
+            if (other is null) return false;
+            if (ReferenceEquals(this, other)) return true;
+
+            return 
+                (
+                    Name == other.Name ||
+                    Name != null &&
+                    Name.Equals(other.Name)
+                ) && 
+                (
+                    NullableName == other.NullableName ||
+                    NullableName != null &&
+                    NullableName.Equals(other.NullableName)
+                );
+        }
+
+        /// <summary>
+        /// Gets the hash code
+        /// </summary>
+        /// <returns>Hash code</returns>
+        public override int GetHashCode()
+        {
+            unchecked // Overflow is fine, just wrap
+            {
+                var hashCode = 41;
+                // Suitable nullity checks etc, of course :)
+                    if (Name != null)
+                    hashCode = hashCode * 59 + Name.GetHashCode();
+                    if (NullableName != null)
+                    hashCode = hashCode * 59 + NullableName.GetHashCode();
+                return hashCode;
+            }
+        }
+
+        #region Operators
+        #pragma warning disable 1591
+
+        public static bool operator ==(TestNullable left, TestNullable right)
+        {
+            return Equals(left, right);
+        }
+
+        public static bool operator !=(TestNullable left, TestNullable right)
+        {
+            return !Equals(left, right);
+        }
+
+        #pragma warning restore 1591
+        #endregion Operators
+    }
+}

samples/server/petstore/aspnetcore-3.1/src/Org.OpenAPITools/wwwroot/openapi-original.json

@@ -812,6 +812,26 @@
         "summary" : "fake endpoint to test parameter example (object)",
         "tags" : [ "fake" ]
       }
+    },
+    "/fake/nullable_example_test" : {
+      "get" : {
+        "description" : "",
+        "operationId" : "fake_nullable_example_test",
+        "responses" : {
+          "200" : {
+            "content" : {
+              "application/json" : {
+                "schema" : {
+                  "$ref" : "#/components/schemas/TestNullable"
+                }
+              }
+            },
+            "description" : "Successful operation"
+          }
+        },
+        "summary" : "Fake endpoint to test nullable example (object)",
+        "tags" : [ "fake" ]
+      }
     }
   },
   "components" : {
@@ -852,6 +872,22 @@
         "enum" : [ "A", "B" ],
         "type" : "string"
       },
+      "TestNullable" : {
+        "example" : {
+          "nullableName" : "nullableName",
+          "name" : "name"
+        },
+        "properties" : {
+          "name" : {
+            "type" : "string"
+          },
+          "nullableName" : {
+            "nullable" : true,
+            "type" : "string"
+          }
+        },
+        "type" : "object"
+      },
       "Order" : {
         "description" : "An order for a pets from the pet store",
         "example" : {

samples/server/petstore/aspnetcore-5.0/.openapi-generator/FILES

@@ -24,6 +24,7 @@ src/Org.OpenAPITools/Models/Order.cs
 src/Org.OpenAPITools/Models/Pet.cs
 src/Org.OpenAPITools/Models/Tag.cs
 src/Org.OpenAPITools/Models/TestEnum.cs
+src/Org.OpenAPITools/Models/TestNullable.cs
 src/Org.OpenAPITools/Models/User.cs
 src/Org.OpenAPITools/OpenApi/TypeExtensions.cs
 src/Org.OpenAPITools/Program.cs

samples/server/petstore/aspnetcore-5.0/src/Org.OpenAPITools/Controllers/FakeApi.cs

@@ -28,6 +28,30 @@ namespace Org.OpenAPITools.Controllers
     [ApiController]
     public class FakeApiController : ControllerBase
     { 
+        /// <summary>
+        /// Fake endpoint to test nullable example (object)
+        /// </summary>
+        /// <response code="200">Successful operation</response>
+        [HttpGet]
+        [Route("/v2/fake/nullable_example_test")]
+        [ValidateModelState]
+        [SwaggerOperation("FakeNullableExampleTest")]
+        [SwaggerResponse(statusCode: 200, type: typeof(TestNullable), description: "Successful operation")]
+        public virtual IActionResult FakeNullableExampleTest()
+        {
+
+            //TODO: Uncomment the next line to return response 200 or use other options such as return this.NotFound(), return this.BadRequest(..), ...
+            // return StatusCode(200, default(TestNullable));
+            string exampleJson = null;
+            exampleJson = "{\n  \"nullableName\" : \"nullableName\",\n  \"name\" : \"name\"\n}";
+            
+            var example = exampleJson != null
+            ? JsonConvert.DeserializeObject<TestNullable>(exampleJson)
+            : default(TestNullable);
+            //TODO: Change the data returned
+            return new ObjectResult(example);
+        }
+
         /// <summary>
         /// fake endpoint to test parameter example (object)
         /// </summary>

samples/server/petstore/aspnetcore-5.0/src/Org.OpenAPITools/Models/TestNullable.cs

@@ -0,0 +1,133 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ * Generated by: https://openapi-generator.tech
+ */
+
+using System;
+using System.Linq;
+using System.Text;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.ComponentModel.DataAnnotations;
+using System.Runtime.Serialization;
+using Newtonsoft.Json;
+using Org.OpenAPITools.Converters;
+
+namespace Org.OpenAPITools.Models
+{ 
+    /// <summary>
+    /// 
+    /// </summary>
+    [DataContract]
+    public partial class TestNullable : IEquatable<TestNullable>
+    {
+        /// <summary>
+        /// Gets or Sets Name
+        /// </summary>
+        [DataMember(Name="name", EmitDefaultValue=false)]
+        public string Name { get; set; }
+
+        /// <summary>
+        /// Gets or Sets NullableName
+        /// </summary>
+        [DataMember(Name="nullableName", EmitDefaultValue=true)]
+        public string NullableName { get; set; }
+
+        /// <summary>
+        /// Returns the string presentation of the object
+        /// </summary>
+        /// <returns>String presentation of the object</returns>
+        public override string ToString()
+        {
+            var sb = new StringBuilder();
+            sb.Append("class TestNullable {\n");
+            sb.Append("  Name: ").Append(Name).Append("\n");
+            sb.Append("  NullableName: ").Append(NullableName).Append("\n");
+            sb.Append("}\n");
+            return sb.ToString();
+        }
+
+        /// <summary>
+        /// Returns the JSON string presentation of the object
+        /// </summary>
+        /// <returns>JSON string presentation of the object</returns>
+        public string ToJson()
+        {
+            return JsonConvert.SerializeObject(this, Formatting.Indented);
+        }
+
+        /// <summary>
+        /// Returns true if objects are equal
+        /// </summary>
+        /// <param name="obj">Object to be compared</param>
+        /// <returns>Boolean</returns>
+        public override bool Equals(object obj)
+        {
+            if (obj is null) return false;
+            if (ReferenceEquals(this, obj)) return true;
+            return obj.GetType() == GetType() && Equals((TestNullable)obj);
+        }
+
+        /// <summary>
+        /// Returns true if TestNullable instances are equal
+        /// </summary>
+        /// <param name="other">Instance of TestNullable to be compared</param>
+        /// <returns>Boolean</returns>
+        public bool Equals(TestNullable other)
+        {
+            if (other is null) return false;
+            if (ReferenceEquals(this, other)) return true;
+
+            return 
+                (
+                    Name == other.Name ||
+                    Name != null &&
+                    Name.Equals(other.Name)
+                ) && 
+                (
+                    NullableName == other.NullableName ||
+                    NullableName != null &&
+                    NullableName.Equals(other.NullableName)
+                );
+        }
+
+        /// <summary>
+        /// Gets the hash code
+        /// </summary>
+        /// <returns>Hash code</returns>
+        public override int GetHashCode()
+        {
+            unchecked // Overflow is fine, just wrap
+            {
+                var hashCode = 41;
+                // Suitable nullity checks etc, of course :)
+                    if (Name != null)
+                    hashCode = hashCode * 59 + Name.GetHashCode();
+                    if (NullableName != null)
+                    hashCode = hashCode * 59 + NullableName.GetHashCode();
+                return hashCode;
+            }
+        }
+
+        #region Operators
+        #pragma warning disable 1591
+
+        public static bool operator ==(TestNullable left, TestNullable right)
+        {
+            return Equals(left, right);
+        }
+
+        public static bool operator !=(TestNullable left, TestNullable right)
+        {
+            return !Equals(left, right);
+        }
+
+        #pragma warning restore 1591
+        #endregion Operators
+    }
+}

samples/server/petstore/aspnetcore-5.0/src/Org.OpenAPITools/wwwroot/openapi-original.json

@@ -812,6 +812,26 @@
         "summary" : "fake endpoint to test parameter example (object)",
         "tags" : [ "fake" ]
       }
+    },
+    "/fake/nullable_example_test" : {
+      "get" : {
+        "description" : "",
+        "operationId" : "fake_nullable_example_test",
+        "responses" : {
+          "200" : {
+            "content" : {
+              "application/json" : {
+                "schema" : {
+                  "$ref" : "#/components/schemas/TestNullable"
+                }
+              }
+            },
+            "description" : "Successful operation"
+          }
+        },
+        "summary" : "Fake endpoint to test nullable example (object)",
+        "tags" : [ "fake" ]
+      }
     }
   },
   "components" : {
@@ -852,6 +872,22 @@
         "enum" : [ "A", "B" ],
         "type" : "string"
       },
+      "TestNullable" : {
+        "example" : {
+          "nullableName" : "nullableName",
+          "name" : "name"
+        },
+        "properties" : {
+          "name" : {
+            "type" : "string"
+          },
+          "nullableName" : {
+            "nullable" : true,
+            "type" : "string"
+          }
+        },
+        "type" : "object"
+      },
       "Order" : {
         "description" : "An order for a pets from the pet store",
         "example" : {

samples/server/petstore/aspnetcore-6.0-NewtonsoftFalse/.openapi-generator/FILES

@@ -24,6 +24,7 @@ src/Org.OpenAPITools/Models/Order.cs
 src/Org.OpenAPITools/Models/Pet.cs
 src/Org.OpenAPITools/Models/Tag.cs
 src/Org.OpenAPITools/Models/TestEnum.cs
+src/Org.OpenAPITools/Models/TestNullable.cs
 src/Org.OpenAPITools/Models/User.cs
 src/Org.OpenAPITools/OpenApi/TypeExtensions.cs
 src/Org.OpenAPITools/Org.OpenAPITools.csproj

samples/server/petstore/aspnetcore-6.0-NewtonsoftFalse/src/Org.OpenAPITools/Controllers/FakeApi.cs

@@ -28,6 +28,30 @@ namespace Org.OpenAPITools.Controllers
     [ApiController]
     public class FakeApiController : ControllerBase
     { 
+        /// <summary>
+        /// Fake endpoint to test nullable example (object)
+        /// </summary>
+        /// <response code="200">Successful operation</response>
+        [HttpGet]
+        [Route("/v2/fake/nullable_example_test")]
+        [ValidateModelState]
+        [SwaggerOperation("FakeNullableExampleTest")]
+        [SwaggerResponse(statusCode: 200, type: typeof(TestNullable), description: "Successful operation")]
+        public virtual IActionResult FakeNullableExampleTest()
+        {
+
+            //TODO: Uncomment the next line to return response 200 or use other options such as return this.NotFound(), return this.BadRequest(..), ...
+            // return StatusCode(200, default(TestNullable));
+            string exampleJson = null;
+            exampleJson = "{\n  \"nullableName\" : \"nullableName\",\n  \"name\" : \"name\"\n}";
+            
+            var example = exampleJson != null
+            ? JsonSerializer.Deserialize<TestNullable>(exampleJson)
+            : default(TestNullable);
+            //TODO: Change the data returned
+            return new ObjectResult(example);
+        }
+
         /// <summary>
         /// fake endpoint to test parameter example (object)
         /// </summary>

samples/server/petstore/aspnetcore-6.0-NewtonsoftFalse/src/Org.OpenAPITools/Models/TestNullable.cs

@@ -0,0 +1,138 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ * Generated by: https://openapi-generator.tech
+ */
+
+using System;
+using System.Linq;
+using System.Text;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.ComponentModel.DataAnnotations;
+using System.Runtime.Serialization;
+using System.Text.Json;
+using Org.OpenAPITools.Converters;
+
+namespace Org.OpenAPITools.Models
+{ 
+    /// <summary>
+    /// 
+    /// </summary>
+    [DataContract]
+    public partial class TestNullable : IEquatable<TestNullable>
+    {
+        /// <summary>
+        /// Gets or Sets Name
+        /// </summary>
+        [DataMember(Name="name", EmitDefaultValue=false)]
+        public string Name { get; set; }
+
+        /// <summary>
+        /// Gets or Sets NullableName
+        /// </summary>
+        [DataMember(Name="nullableName", EmitDefaultValue=true)]
+        public string NullableName { get; set; }
+
+        /// <summary>
+        /// Returns the string presentation of the object
+        /// </summary>
+        /// <returns>String presentation of the object</returns>
+        public override string ToString()
+        {
+            var sb = new StringBuilder();
+            sb.Append("class TestNullable {\n");
+            sb.Append("  Name: ").Append(Name).Append("\n");
+            sb.Append("  NullableName: ").Append(NullableName).Append("\n");
+            sb.Append("}\n");
+            return sb.ToString();
+        }
+
+        /// <summary>
+        /// Returns the JSON string presentation of the object
+        /// </summary>
+        /// <returns>JSON string presentation of the object</returns>
+        public string ToJson()
+        {
+            var options = new JsonSerializerOptions
+            {
+                WriteIndented = true
+            };
+
+            return JsonSerializer.Serialize(this, options);
+        }
+
+        /// <summary>
+        /// Returns true if objects are equal
+        /// </summary>
+        /// <param name="obj">Object to be compared</param>
+        /// <returns>Boolean</returns>
+        public override bool Equals(object obj)
+        {
+            if (obj is null) return false;
+            if (ReferenceEquals(this, obj)) return true;
+            return obj.GetType() == GetType() && Equals((TestNullable)obj);
+        }
+
+        /// <summary>
+        /// Returns true if TestNullable instances are equal
+        /// </summary>
+        /// <param name="other">Instance of TestNullable to be compared</param>
+        /// <returns>Boolean</returns>
+        public bool Equals(TestNullable other)
+        {
+            if (other is null) return false;
+            if (ReferenceEquals(this, other)) return true;
+
+            return 
+                (
+                    Name == other.Name ||
+                    Name != null &&
+                    Name.Equals(other.Name)
+                ) && 
+                (
+                    NullableName == other.NullableName ||
+                    NullableName != null &&
+                    NullableName.Equals(other.NullableName)
+                );
+        }
+
+        /// <summary>
+        /// Gets the hash code
+        /// </summary>
+        /// <returns>Hash code</returns>
+        public override int GetHashCode()
+        {
+            unchecked // Overflow is fine, just wrap
+            {
+                var hashCode = 41;
+                // Suitable nullity checks etc, of course :)
+                    if (Name != null)
+                    hashCode = hashCode * 59 + Name.GetHashCode();
+                    if (NullableName != null)
+                    hashCode = hashCode * 59 + NullableName.GetHashCode();
+                return hashCode;
+            }
+        }
+
+        #region Operators
+        #pragma warning disable 1591
+
+        public static bool operator ==(TestNullable left, TestNullable right)
+        {
+            return Equals(left, right);
+        }
+
+        public static bool operator !=(TestNullable left, TestNullable right)
+        {
+            return !Equals(left, right);
+        }
+
+        #pragma warning restore 1591
+        #endregion Operators
+    }
+}

samples/server/petstore/aspnetcore-6.0-NewtonsoftFalse/src/Org.OpenAPITools/wwwroot/openapi-original.json

@@ -812,6 +812,26 @@
         "summary" : "fake endpoint to test parameter example (object)",
         "tags" : [ "fake" ]
       }
+    },
+    "/fake/nullable_example_test" : {
+      "get" : {
+        "description" : "",
+        "operationId" : "fake_nullable_example_test",
+        "responses" : {
+          "200" : {
+            "content" : {
+              "application/json" : {
+                "schema" : {
+                  "$ref" : "#/components/schemas/TestNullable"
+                }
+              }
+            },
+            "description" : "Successful operation"
+          }
+        },
+        "summary" : "Fake endpoint to test nullable example (object)",
+        "tags" : [ "fake" ]
+      }
     }
   },
   "components" : {
@@ -852,6 +872,22 @@
         "enum" : [ "A", "B" ],
         "type" : "string"
       },
+      "TestNullable" : {
+        "example" : {
+          "nullableName" : "nullableName",
+          "name" : "name"
+        },
+        "properties" : {
+          "name" : {
+            "type" : "string"
+          },
+          "nullableName" : {
+            "nullable" : true,
+            "type" : "string"
+          }
+        },
+        "type" : "object"
+      },
       "Order" : {
         "description" : "An order for a pets from the pet store",
         "example" : {

samples/server/petstore/aspnetcore-6.0-nullableReferenceTypes/.openapi-generator/FILES

@@ -24,6 +24,7 @@ src/Org.OpenAPITools/Models/Order.cs
 src/Org.OpenAPITools/Models/Pet.cs
 src/Org.OpenAPITools/Models/Tag.cs
 src/Org.OpenAPITools/Models/TestEnum.cs
+src/Org.OpenAPITools/Models/TestNullable.cs
 src/Org.OpenAPITools/Models/User.cs
 src/Org.OpenAPITools/OpenApi/TypeExtensions.cs
 src/Org.OpenAPITools/Org.OpenAPITools.csproj

samples/server/petstore/aspnetcore-6.0-nullableReferenceTypes/src/Org.OpenAPITools/Controllers/FakeApi.cs

@@ -28,6 +28,30 @@ namespace Org.OpenAPITools.Controllers
     [ApiController]
     public class FakeApiController : ControllerBase
     { 
+        /// <summary>
+        /// Fake endpoint to test nullable example (object)
+        /// </summary>
+        /// <response code="200">Successful operation</response>
+        [HttpGet]
+        [Route("/v2/fake/nullable_example_test")]
+        [ValidateModelState]
+        [SwaggerOperation("FakeNullableExampleTest")]
+        [SwaggerResponse(statusCode: 200, type: typeof(TestNullable), description: "Successful operation")]
+        public virtual IActionResult FakeNullableExampleTest()
+        {
+
+            //TODO: Uncomment the next line to return response 200 or use other options such as return this.NotFound(), return this.BadRequest(..), ...
+            // return StatusCode(200, default(TestNullable));
+            string exampleJson = null;
+            exampleJson = "{\n  \"nullableName\" : \"nullableName\",\n  \"name\" : \"name\"\n}";
+            
+            var example = exampleJson != null
+            ? JsonConvert.DeserializeObject<TestNullable>(exampleJson)
+            : default(TestNullable);
+            //TODO: Change the data returned
+            return new ObjectResult(example);
+        }
+
         /// <summary>
         /// fake endpoint to test parameter example (object)
         /// </summary>

samples/server/petstore/aspnetcore-6.0-nullableReferenceTypes/src/Org.OpenAPITools/Models/TestNullable.cs

@@ -0,0 +1,133 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ * Generated by: https://openapi-generator.tech
+ */
+
+using System;
+using System.Linq;
+using System.Text;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.ComponentModel.DataAnnotations;
+using System.Runtime.Serialization;
+using Newtonsoft.Json;
+using Org.OpenAPITools.Converters;
+
+namespace Org.OpenAPITools.Models
+{ 
+    /// <summary>
+    /// 
+    /// </summary>
+    [DataContract]
+    public partial class TestNullable : IEquatable<TestNullable>
+    {
+        /// <summary>
+        /// Gets or Sets Name
+        /// </summary>
+        [DataMember(Name="name", EmitDefaultValue=false)]
+        public string? Name { get; set; }
+
+        /// <summary>
+        /// Gets or Sets NullableName
+        /// </summary>
+        [DataMember(Name="nullableName", EmitDefaultValue=true)]
+        public string? NullableName { get; set; }
+
+        /// <summary>
+        /// Returns the string presentation of the object
+        /// </summary>
+        /// <returns>String presentation of the object</returns>
+        public override string ToString()
+        {
+            var sb = new StringBuilder();
+            sb.Append("class TestNullable {\n");
+            sb.Append("  Name: ").Append(Name).Append("\n");
+            sb.Append("  NullableName: ").Append(NullableName).Append("\n");
+            sb.Append("}\n");
+            return sb.ToString();
+        }
+
+        /// <summary>
+        /// Returns the JSON string presentation of the object
+        /// </summary>
+        /// <returns>JSON string presentation of the object</returns>
+        public string ToJson()
+        {
+            return JsonConvert.SerializeObject(this, Formatting.Indented);
+        }
+
+        /// <summary>
+        /// Returns true if objects are equal
+        /// </summary>
+        /// <param name="obj">Object to be compared</param>
+        /// <returns>Boolean</returns>
+        public override bool Equals(object obj)
+        {
+            if (obj is null) return false;
+            if (ReferenceEquals(this, obj)) return true;
+            return obj.GetType() == GetType() && Equals((TestNullable)obj);
+        }
+
+        /// <summary>
+        /// Returns true if TestNullable instances are equal
+        /// </summary>
+        /// <param name="other">Instance of TestNullable to be compared</param>
+        /// <returns>Boolean</returns>
+        public bool Equals(TestNullable other)
+        {
+            if (other is null) return false;
+            if (ReferenceEquals(this, other)) return true;
+
+            return 
+                (
+                    Name == other.Name ||
+                    Name != null &&
+                    Name.Equals(other.Name)
+                ) && 
+                (
+                    NullableName == other.NullableName ||
+                    NullableName != null &&
+                    NullableName.Equals(other.NullableName)
+                );
+        }
+
+        /// <summary>
+        /// Gets the hash code
+        /// </summary>
+        /// <returns>Hash code</returns>
+        public override int GetHashCode()
+        {
+            unchecked // Overflow is fine, just wrap
+            {
+                var hashCode = 41;
+                // Suitable nullity checks etc, of course :)
+                    if (Name != null)
+                    hashCode = hashCode * 59 + Name.GetHashCode();
+                    if (NullableName != null)
+                    hashCode = hashCode * 59 + NullableName.GetHashCode();
+                return hashCode;
+            }
+        }
+
+        #region Operators
+        #pragma warning disable 1591
+
+        public static bool operator ==(TestNullable left, TestNullable right)
+        {
+            return Equals(left, right);
+        }
+
+        public static bool operator !=(TestNullable left, TestNullable right)
+        {
+            return !Equals(left, right);
+        }
+
+        #pragma warning restore 1591
+        #endregion Operators
+    }
+}

samples/server/petstore/aspnetcore-6.0-nullableReferenceTypes/src/Org.OpenAPITools/wwwroot/openapi-original.json

@@ -812,6 +812,26 @@
         "summary" : "fake endpoint to test parameter example (object)",
         "tags" : [ "fake" ]
       }
+    },
+    "/fake/nullable_example_test" : {
+      "get" : {
+        "description" : "",
+        "operationId" : "fake_nullable_example_test",
+        "responses" : {
+          "200" : {
+            "content" : {
+              "application/json" : {
+                "schema" : {
+                  "$ref" : "#/components/schemas/TestNullable"
+                }
+              }
+            },
+            "description" : "Successful operation"
+          }
+        },
+        "summary" : "Fake endpoint to test nullable example (object)",
+        "tags" : [ "fake" ]
+      }
     }
   },
   "components" : {
@@ -852,6 +872,22 @@
         "enum" : [ "A", "B" ],
         "type" : "string"
       },
+      "TestNullable" : {
+        "example" : {
+          "nullableName" : "nullableName",
+          "name" : "name"
+        },
+        "properties" : {
+          "name" : {
+            "type" : "string"
+          },
+          "nullableName" : {
+            "nullable" : true,
+            "type" : "string"
+          }
+        },
+        "type" : "object"
+      },
       "Order" : {
         "description" : "An order for a pets from the pet store",
         "example" : {

samples/server/petstore/aspnetcore-6.0-pocoModels/.openapi-generator/FILES

@@ -24,6 +24,7 @@ src/Org.OpenAPITools/Models/Order.cs
 src/Org.OpenAPITools/Models/Pet.cs
 src/Org.OpenAPITools/Models/Tag.cs
 src/Org.OpenAPITools/Models/TestEnum.cs
+src/Org.OpenAPITools/Models/TestNullable.cs
 src/Org.OpenAPITools/Models/User.cs
 src/Org.OpenAPITools/OpenApi/TypeExtensions.cs
 src/Org.OpenAPITools/Org.OpenAPITools.csproj

samples/server/petstore/aspnetcore-6.0-pocoModels/src/Org.OpenAPITools/Controllers/FakeApi.cs

@@ -28,6 +28,30 @@ namespace Org.OpenAPITools.Controllers
     [ApiController]
     public class FakeApiController : ControllerBase
     { 
+        /// <summary>
+        /// Fake endpoint to test nullable example (object)
+        /// </summary>
+        /// <response code="200">Successful operation</response>
+        [HttpGet]
+        [Route("/v2/fake/nullable_example_test")]
+        [ValidateModelState]
+        [SwaggerOperation("FakeNullableExampleTest")]
+        [SwaggerResponse(statusCode: 200, type: typeof(TestNullable), description: "Successful operation")]
+        public virtual IActionResult FakeNullableExampleTest()
+        {
+
+            //TODO: Uncomment the next line to return response 200 or use other options such as return this.NotFound(), return this.BadRequest(..), ...
+            // return StatusCode(200, default(TestNullable));
+            string exampleJson = null;
+            exampleJson = "{\n  \"nullableName\" : \"nullableName\",\n  \"name\" : \"name\"\n}";
+            
+            var example = exampleJson != null
+            ? JsonConvert.DeserializeObject<TestNullable>(exampleJson)
+            : default(TestNullable);
+            //TODO: Change the data returned
+            return new ObjectResult(example);
+        }
+
         /// <summary>
         /// fake endpoint to test parameter example (object)
         /// </summary>

samples/server/petstore/aspnetcore-6.0-pocoModels/src/Org.OpenAPITools/Models/TestNullable.cs

@@ -0,0 +1,42 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ * Generated by: https://openapi-generator.tech
+ */
+
+using System;
+using System.Linq;
+using System.Text;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.ComponentModel.DataAnnotations;
+using System.Runtime.Serialization;
+using Newtonsoft.Json;
+using Org.OpenAPITools.Converters;
+
+namespace Org.OpenAPITools.Models
+{ 
+    /// <summary>
+    /// 
+    /// </summary>
+    [DataContract]
+    public partial class TestNullable 
+    {
+        /// <summary>
+        /// Gets or Sets Name
+        /// </summary>
+        [DataMember(Name="name", EmitDefaultValue=false)]
+        public string Name { get; set; }
+
+        /// <summary>
+        /// Gets or Sets NullableName
+        /// </summary>
+        [DataMember(Name="nullableName", EmitDefaultValue=true)]
+        public string NullableName { get; set; }
+
+    }
+}

samples/server/petstore/aspnetcore-6.0-pocoModels/src/Org.OpenAPITools/wwwroot/openapi-original.json

@@ -812,6 +812,26 @@
         "summary" : "fake endpoint to test parameter example (object)",
         "tags" : [ "fake" ]
       }
+    },
+    "/fake/nullable_example_test" : {
+      "get" : {
+        "description" : "",
+        "operationId" : "fake_nullable_example_test",
+        "responses" : {
+          "200" : {
+            "content" : {
+              "application/json" : {
+                "schema" : {
+                  "$ref" : "#/components/schemas/TestNullable"
+                }
+              }
+            },
+            "description" : "Successful operation"
+          }
+        },
+        "summary" : "Fake endpoint to test nullable example (object)",
+        "tags" : [ "fake" ]
+      }
     }
   },
   "components" : {
@@ -852,6 +872,22 @@
         "enum" : [ "A", "B" ],
         "type" : "string"
       },
+      "TestNullable" : {
+        "example" : {
+          "nullableName" : "nullableName",
+          "name" : "name"
+        },
+        "properties" : {
+          "name" : {
+            "type" : "string"
+          },
+          "nullableName" : {
+            "nullable" : true,
+            "type" : "string"
+          }
+        },
+        "type" : "object"
+      },
       "Order" : {
         "description" : "An order for a pets from the pet store",
         "example" : {

samples/server/petstore/aspnetcore-6.0-project4Models/.openapi-generator/FILES

@@ -14,6 +14,7 @@ src/Org.OpenAPITools.Models/Org.OpenAPITools.Models.csproj
 src/Org.OpenAPITools.Models/Pet.cs
 src/Org.OpenAPITools.Models/Tag.cs
 src/Org.OpenAPITools.Models/TestEnum.cs
+src/Org.OpenAPITools.Models/TestNullable.cs
 src/Org.OpenAPITools.Models/User.cs
 src/Org.OpenAPITools/.gitignore
 src/Org.OpenAPITools/Attributes/ValidateModelStateAttribute.cs

samples/server/petstore/aspnetcore-6.0-project4Models/src/Org.OpenAPITools.Models/TestNullable.cs

@@ -0,0 +1,133 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ * Generated by: https://openapi-generator.tech
+ */
+
+using System;
+using System.Linq;
+using System.Text;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.ComponentModel.DataAnnotations;
+using System.Runtime.Serialization;
+using Newtonsoft.Json;
+using Org.OpenAPITools.Converters;
+
+namespace Org.OpenAPITools.Models
+{ 
+    /// <summary>
+    /// 
+    /// </summary>
+    [DataContract]
+    public partial class TestNullable : IEquatable<TestNullable>
+    {
+        /// <summary>
+        /// Gets or Sets Name
+        /// </summary>
+        [DataMember(Name="name", EmitDefaultValue=false)]
+        public string Name { get; set; }
+
+        /// <summary>
+        /// Gets or Sets NullableName
+        /// </summary>
+        [DataMember(Name="nullableName", EmitDefaultValue=true)]
+        public string NullableName { get; set; }
+
+        /// <summary>
+        /// Returns the string presentation of the object
+        /// </summary>
+        /// <returns>String presentation of the object</returns>
+        public override string ToString()
+        {
+            var sb = new StringBuilder();
+            sb.Append("class TestNullable {\n");
+            sb.Append("  Name: ").Append(Name).Append("\n");
+            sb.Append("  NullableName: ").Append(NullableName).Append("\n");
+            sb.Append("}\n");
+            return sb.ToString();
+        }
+
+        /// <summary>
+        /// Returns the JSON string presentation of the object
+        /// </summary>
+        /// <returns>JSON string presentation of the object</returns>
+        public string ToJson()
+        {
+            return JsonConvert.SerializeObject(this, Formatting.Indented);
+        }
+
+        /// <summary>
+        /// Returns true if objects are equal
+        /// </summary>
+        /// <param name="obj">Object to be compared</param>
+        /// <returns>Boolean</returns>
+        public override bool Equals(object obj)
+        {
+            if (obj is null) return false;
+            if (ReferenceEquals(this, obj)) return true;
+            return obj.GetType() == GetType() && Equals((TestNullable)obj);
+        }
+
+        /// <summary>
+        /// Returns true if TestNullable instances are equal
+        /// </summary>
+        /// <param name="other">Instance of TestNullable to be compared</param>
+        /// <returns>Boolean</returns>
+        public bool Equals(TestNullable other)
+        {
+            if (other is null) return false;
+            if (ReferenceEquals(this, other)) return true;
+
+            return 
+                (
+                    Name == other.Name ||
+                    Name != null &&
+                    Name.Equals(other.Name)
+                ) && 
+                (
+                    NullableName == other.NullableName ||
+                    NullableName != null &&
+                    NullableName.Equals(other.NullableName)
+                );
+        }
+
+        /// <summary>
+        /// Gets the hash code
+        /// </summary>
+        /// <returns>Hash code</returns>
+        public override int GetHashCode()
+        {
+            unchecked // Overflow is fine, just wrap
+            {
+                var hashCode = 41;
+                // Suitable nullity checks etc, of course :)
+                    if (Name != null)
+                    hashCode = hashCode * 59 + Name.GetHashCode();
+                    if (NullableName != null)
+                    hashCode = hashCode * 59 + NullableName.GetHashCode();
+                return hashCode;
+            }
+        }
+
+        #region Operators
+        #pragma warning disable 1591
+
+        public static bool operator ==(TestNullable left, TestNullable right)
+        {
+            return Equals(left, right);
+        }
+
+        public static bool operator !=(TestNullable left, TestNullable right)
+        {
+            return !Equals(left, right);
+        }
+
+        #pragma warning restore 1591
+        #endregion Operators
+    }
+}

samples/server/petstore/aspnetcore-6.0-project4Models/src/Org.OpenAPITools/Controllers/FakeApi.cs

@@ -28,6 +28,30 @@ namespace Org.OpenAPITools.Controllers
     [ApiController]
     public class FakeApiController : ControllerBase
     { 
+        /// <summary>
+        /// Fake endpoint to test nullable example (object)
+        /// </summary>
+        /// <response code="200">Successful operation</response>
+        [HttpGet]
+        [Route("/v2/fake/nullable_example_test")]
+        [ValidateModelState]
+        [SwaggerOperation("FakeNullableExampleTest")]
+        [SwaggerResponse(statusCode: 200, type: typeof(TestNullable), description: "Successful operation")]
+        public virtual IActionResult FakeNullableExampleTest()
+        {
+
+            //TODO: Uncomment the next line to return response 200 or use other options such as return this.NotFound(), return this.BadRequest(..), ...
+            // return StatusCode(200, default(TestNullable));
+            string exampleJson = null;
+            exampleJson = "{\n  \"nullableName\" : \"nullableName\",\n  \"name\" : \"name\"\n}";
+            
+            var example = exampleJson != null
+            ? JsonConvert.DeserializeObject<TestNullable>(exampleJson)
+            : default(TestNullable);
+            //TODO: Change the data returned
+            return new ObjectResult(example);
+        }
+
         /// <summary>
         /// fake endpoint to test parameter example (object)
         /// </summary>

samples/server/petstore/aspnetcore-6.0-project4Models/src/Org.OpenAPITools/wwwroot/openapi-original.json

@@ -812,6 +812,26 @@
         "summary" : "fake endpoint to test parameter example (object)",
         "tags" : [ "fake" ]
       }
+    },
+    "/fake/nullable_example_test" : {
+      "get" : {
+        "description" : "",
+        "operationId" : "fake_nullable_example_test",
+        "responses" : {
+          "200" : {
+            "content" : {
+              "application/json" : {
+                "schema" : {
+                  "$ref" : "#/components/schemas/TestNullable"
+                }
+              }
+            },
+            "description" : "Successful operation"
+          }
+        },
+        "summary" : "Fake endpoint to test nullable example (object)",
+        "tags" : [ "fake" ]
+      }
     }
   },
   "components" : {
@@ -852,6 +872,22 @@
         "enum" : [ "A", "B" ],
         "type" : "string"
       },
+      "TestNullable" : {
+        "example" : {
+          "nullableName" : "nullableName",
+          "name" : "name"
+        },
+        "properties" : {
+          "name" : {
+            "type" : "string"
+          },
+          "nullableName" : {
+            "nullable" : true,
+            "type" : "string"
+          }
+        },
+        "type" : "object"
+      },
       "Order" : {
         "description" : "An order for a pets from the pet store",
         "example" : {

samples/server/petstore/aspnetcore-6.0-useSwashBuckle/.openapi-generator/FILES

@@ -21,6 +21,7 @@ src/Org.OpenAPITools/Models/Order.cs
 src/Org.OpenAPITools/Models/Pet.cs
 src/Org.OpenAPITools/Models/Tag.cs
 src/Org.OpenAPITools/Models/TestEnum.cs
+src/Org.OpenAPITools/Models/TestNullable.cs
 src/Org.OpenAPITools/Models/User.cs
 src/Org.OpenAPITools/OpenApi/TypeExtensions.cs
 src/Org.OpenAPITools/Org.OpenAPITools.csproj

samples/server/petstore/aspnetcore-6.0-useSwashBuckle/src/Org.OpenAPITools/Controllers/FakeApi.cs

@@ -25,6 +25,16 @@ namespace Org.OpenAPITools.Controllers
     [ApiController]
     public abstract class FakeApiController : ControllerBase
     { 
+        /// <summary>
+        /// Fake endpoint to test nullable example (object)
+        /// </summary>
+        /// <response code="200">Successful operation</response>
+        [HttpGet]
+        [Route("/v2/fake/nullable_example_test")]
+        [ValidateModelState]
+        [ProducesResponseType(statusCode: 200, type: typeof(TestNullable))]
+        public abstract IActionResult FakeNullableExampleTest();
+
         /// <summary>
         /// fake endpoint to test parameter example (object)
         /// </summary>

samples/server/petstore/aspnetcore-6.0-useSwashBuckle/src/Org.OpenAPITools/Models/TestNullable.cs

@@ -0,0 +1,133 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ * Generated by: https://openapi-generator.tech
+ */
+
+using System;
+using System.Linq;
+using System.Text;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.ComponentModel.DataAnnotations;
+using System.Runtime.Serialization;
+using Newtonsoft.Json;
+using Org.OpenAPITools.Converters;
+
+namespace Org.OpenAPITools.Models
+{ 
+    /// <summary>
+    /// 
+    /// </summary>
+    [DataContract]
+    public class TestNullable : IEquatable<TestNullable>
+    {
+        /// <summary>
+        /// Gets or Sets Name
+        /// </summary>
+        [DataMember(Name="name", EmitDefaultValue=false)]
+        public string Name { get; set; }
+
+        /// <summary>
+        /// Gets or Sets NullableName
+        /// </summary>
+        [DataMember(Name="nullableName", EmitDefaultValue=true)]
+        public string NullableName { get; set; }
+
+        /// <summary>
+        /// Returns the string presentation of the object
+        /// </summary>
+        /// <returns>String presentation of the object</returns>
+        public override string ToString()
+        {
+            var sb = new StringBuilder();
+            sb.Append("class TestNullable {\n");
+            sb.Append("  Name: ").Append(Name).Append("\n");
+            sb.Append("  NullableName: ").Append(NullableName).Append("\n");
+            sb.Append("}\n");
+            return sb.ToString();
+        }
+
+        /// <summary>
+        /// Returns the JSON string presentation of the object
+        /// </summary>
+        /// <returns>JSON string presentation of the object</returns>
+        public string ToJson()
+        {
+            return JsonConvert.SerializeObject(this, Formatting.Indented);
+        }
+
+        /// <summary>
+        /// Returns true if objects are equal
+        /// </summary>
+        /// <param name="obj">Object to be compared</param>
+        /// <returns>Boolean</returns>
+        public override bool Equals(object obj)
+        {
+            if (obj is null) return false;
+            if (ReferenceEquals(this, obj)) return true;
+            return obj.GetType() == GetType() && Equals((TestNullable)obj);
+        }
+
+        /// <summary>
+        /// Returns true if TestNullable instances are equal
+        /// </summary>
+        /// <param name="other">Instance of TestNullable to be compared</param>
+        /// <returns>Boolean</returns>
+        public bool Equals(TestNullable other)
+        {
+            if (other is null) return false;
+            if (ReferenceEquals(this, other)) return true;
+
+            return 
+                (
+                    Name == other.Name ||
+                    Name != null &&
+                    Name.Equals(other.Name)
+                ) && 
+                (
+                    NullableName == other.NullableName ||
+                    NullableName != null &&
+                    NullableName.Equals(other.NullableName)
+                );
+        }
+
+        /// <summary>
+        /// Gets the hash code
+        /// </summary>
+        /// <returns>Hash code</returns>
+        public override int GetHashCode()
+        {
+            unchecked // Overflow is fine, just wrap
+            {
+                var hashCode = 41;
+                // Suitable nullity checks etc, of course :)
+                    if (Name != null)
+                    hashCode = hashCode * 59 + Name.GetHashCode();
+                    if (NullableName != null)
+                    hashCode = hashCode * 59 + NullableName.GetHashCode();
+                return hashCode;
+            }
+        }
+
+        #region Operators
+        #pragma warning disable 1591
+
+        public static bool operator ==(TestNullable left, TestNullable right)
+        {
+            return Equals(left, right);
+        }
+
+        public static bool operator !=(TestNullable left, TestNullable right)
+        {
+            return !Equals(left, right);
+        }
+
+        #pragma warning restore 1591
+        #endregion Operators
+    }
+}

samples/server/petstore/aspnetcore-6.0/.openapi-generator/FILES

@@ -24,6 +24,7 @@ src/Org.OpenAPITools/Models/Order.cs
 src/Org.OpenAPITools/Models/Pet.cs
 src/Org.OpenAPITools/Models/Tag.cs
 src/Org.OpenAPITools/Models/TestEnum.cs
+src/Org.OpenAPITools/Models/TestNullable.cs
 src/Org.OpenAPITools/Models/User.cs
 src/Org.OpenAPITools/OpenApi/TypeExtensions.cs
 src/Org.OpenAPITools/Org.OpenAPITools.csproj

samples/server/petstore/aspnetcore-6.0/src/Org.OpenAPITools/Controllers/FakeApi.cs

@@ -28,6 +28,30 @@ namespace Org.OpenAPITools.Controllers
     [ApiController]
     public class FakeApiController : ControllerBase
     { 
+        /// <summary>
+        /// Fake endpoint to test nullable example (object)
+        /// </summary>
+        /// <response code="200">Successful operation</response>
+        [HttpGet]
+        [Route("/v2/fake/nullable_example_test")]
+        [ValidateModelState]
+        [SwaggerOperation("FakeNullableExampleTest")]
+        [SwaggerResponse(statusCode: 200, type: typeof(TestNullable), description: "Successful operation")]
+        public virtual IActionResult FakeNullableExampleTest()
+        {
+
+            //TODO: Uncomment the next line to return response 200 or use other options such as return this.NotFound(), return this.BadRequest(..), ...
+            // return StatusCode(200, default(TestNullable));
+            string exampleJson = null;
+            exampleJson = "{\n  \"nullableName\" : \"nullableName\",\n  \"name\" : \"name\"\n}";
+            
+            var example = exampleJson != null
+            ? JsonConvert.DeserializeObject<TestNullable>(exampleJson)
+            : default(TestNullable);
+            //TODO: Change the data returned
+            return new ObjectResult(example);
+        }
+
         /// <summary>
         /// fake endpoint to test parameter example (object)
         /// </summary>

samples/server/petstore/aspnetcore-6.0/src/Org.OpenAPITools/Models/TestNullable.cs

@@ -0,0 +1,133 @@
+/*
+ * OpenAPI Petstore
+ *
+ * This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ * Generated by: https://openapi-generator.tech
+ */
+
+using System;
+using System.Linq;
+using System.Text;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.ComponentModel.DataAnnotations;
+using System.Runtime.Serialization;
+using Newtonsoft.Json;
+using Org.OpenAPITools.Converters;
+
+namespace Org.OpenAPITools.Models
+{ 
+    /// <summary>
+    /// 
+    /// </summary>
+    [DataContract]
+    public partial class TestNullable : IEquatable<TestNullable>
+    {
+        /// <summary>
+        /// Gets or Sets Name
+        /// </summary>
+        [DataMember(Name="name", EmitDefaultValue=false)]
+        public string Name { get; set; }
+
+        /// <summary>
+        /// Gets or Sets NullableName
+        /// </summary>
+        [DataMember(Name="nullableName", EmitDefaultValue=true)]
+        public string NullableName { get; set; }
+
+        /// <summary>
+        /// Returns the string presentation of the object
+        /// </summary>
+        /// <returns>String presentation of the object</returns>
+        public override string ToString()
+        {
+            var sb = new StringBuilder();
+            sb.Append("class TestNullable {\n");
+            sb.Append("  Name: ").Append(Name).Append("\n");
+            sb.Append("  NullableName: ").Append(NullableName).Append("\n");
+            sb.Append("}\n");
+            return sb.ToString();
+        }
+
+        /// <summary>
+        /// Returns the JSON string presentation of the object
+        /// </summary>
+        /// <returns>JSON string presentation of the object</returns>
+        public string ToJson()
+        {
+            return JsonConvert.SerializeObject(this, Formatting.Indented);
+        }
+
+        /// <summary>
+        /// Returns true if objects are equal
+        /// </summary>
+        /// <param name="obj">Object to be compared</param>
+        /// <returns>Boolean</returns>
+        public override bool Equals(object obj)
+        {
+            if (obj is null) return false;
+            if (ReferenceEquals(this, obj)) return true;
+            return obj.GetType() == GetType() && Equals((TestNullable)obj);
+        }
+
+        /// <summary>
+        /// Returns true if TestNullable instances are equal
+        /// </summary>
+        /// <param name="other">Instance of TestNullable to be compared</param>
+        /// <returns>Boolean</returns>
+        public bool Equals(TestNullable other)
+        {
+            if (other is null) return false;
+            if (ReferenceEquals(this, other)) return true;
+
+            return 
+                (
+                    Name == other.Name ||
+                    Name != null &&
+                    Name.Equals(other.Name)
+                ) && 
+                (
+                    NullableName == other.NullableName ||
+                    NullableName != null &&
+                    NullableName.Equals(other.NullableName)
+                );
+        }
+
+        /// <summary>
+        /// Gets the hash code
+        /// </summary>
+        /// <returns>Hash code</returns>
+        public override int GetHashCode()
+        {
+            unchecked // Overflow is fine, just wrap
+            {
+                var hashCode = 41;
+                // Suitable nullity checks etc, of course :)
+                    if (Name != null)
+                    hashCode = hashCode * 59 + Name.GetHashCode();
+                    if (NullableName != null)
+                    hashCode = hashCode * 59 + NullableName.GetHashCode();
+                return hashCode;
+            }
+        }
+
+        #region Operators
+        #pragma warning disable 1591
+
+        public static bool operator ==(TestNullable left, TestNullable right)
+        {
+            return Equals(left, right);
+        }
+
+        public static bool operator !=(TestNullable left, TestNullable right)
+        {
+            return !Equals(left, right);
+        }
+
+        #pragma warning restore 1591
+        #endregion Operators
+    }
+}

samples/server/petstore/aspnetcore-6.0/src/Org.OpenAPITools/wwwroot/openapi-original.json

@@ -812,6 +812,26 @@
         "summary" : "fake endpoint to test parameter example (object)",
         "tags" : [ "fake" ]
       }
+    },
+    "/fake/nullable_example_test" : {
+      "get" : {
+        "description" : "",
+        "operationId" : "fake_nullable_example_test",
+        "responses" : {
+          "200" : {
+            "content" : {
+              "application/json" : {
+                "schema" : {
+                  "$ref" : "#/components/schemas/TestNullable"
+                }
+              }
+            },
+            "description" : "Successful operation"
+          }
+        },
+        "summary" : "Fake endpoint to test nullable example (object)",
+        "tags" : [ "fake" ]
+      }
     }
   },
   "components" : {
@@ -852,6 +872,22 @@
         "enum" : [ "A", "B" ],
         "type" : "string"
       },
+      "TestNullable" : {
+        "example" : {
+          "nullableName" : "nullableName",
+          "name" : "name"
+        },
+        "properties" : {
+          "name" : {
+            "type" : "string"
+          },
+          "nullableName" : {
+            "nullable" : true,
+            "type" : "string"
+          }
+        },
+        "type" : "object"
+      },
       "Order" : {
         "description" : "An order for a pets from the pet store",
         "example" : {