Azure · Dresel · Jan 24, 2024
diff --git a/src/Microsoft.Azure.WebJobs.Extensions.OpenApi.Core/DocumentHelper.cs b/src/Microsoft.Azure.WebJobs.Extensions.OpenApi.Core/DocumentHelper.cs
@@ -135,7 +135,8 @@ public Dictionary<string, OpenApiSchema> GetOpenApiSchemas(List<MethodInfo> elem
             var responses = elements.SelectMany(p => p.GetCustomAttributes<OpenApiResponseWithBodyAttribute>(inherit: false))
                                     .Select(p => p.BodyType);
             var types = requests.Union(responses)
-                                .Select(p => p.IsOpenApiArray() || p.IsOpenApiDictionary() ? p.GetOpenApiSubType() : p)
+                                .SelectMany(p => p.IsReferencedOpenApiArray() ? new[] { p, p.GetOpenApiSubType() } :
+                                    p.IsOpenApiArray() || p.IsOpenApiDictionary() ? new [] { p.GetOpenApiSubType() } : new[] { p })
                                 .Distinct()
                                 .Where(p => !p.IsSimpleType())
                                 .Where(p => p.IsReferentialType())

diff --git a/...t.Azure.WebJobs.Extensions.OpenApi.Core/Extensions/OpenApiParameterAttributeExtensions.cs b/...t.Azure.WebJobs.Extensions.OpenApi.Core/Extensions/OpenApiParameterAttributeExtensions.cs
@@ -53,7 +53,7 @@ public static OpenApiParameter ToOpenApiParameter(this OpenApiParameterAttribute
                 Schema = schema
             };
 
-            if (type.IsOpenApiArray())
+            if (type.IsOpenApiArray() || type.IsReferencedOpenApiArray())
             {
                 if (attribute.In == ParameterLocation.Path)
                 {

diff --git a/...oft.Azure.WebJobs.Extensions.OpenApi.Core/Extensions/OpenApiPayloadAttributeExtensions.cs b/...oft.Azure.WebJobs.Extensions.OpenApi.Core/Extensions/OpenApiPayloadAttributeExtensions.cs
@@ -55,7 +55,7 @@ public static OpenApiMediaType ToOpenApiMediaType<T>(this T attribute, NamingStr
             }
 
             // For array and dictionary object, the reference has already been added by the visitor.
-            if (type.IsReferentialType() && !type.IsOpenApiNullable() && !type.IsOpenApiArray() && !type.IsOpenApiDictionary())
+            if (type.IsReferentialType() && !type.IsOpenApiNullable() && !type.IsOpenApiArray() && !type.IsReferencedOpenApiArray() && !type.IsOpenApiDictionary())
             {
                 var reference = new OpenApiReference()
                 {

diff --git a/src/Microsoft.Azure.WebJobs.Extensions.OpenApi.Core/Extensions/TypeExtensions.cs b/src/Microsoft.Azure.WebJobs.Extensions.OpenApi.Core/Extensions/TypeExtensions.cs
@@ -322,6 +322,21 @@ public static bool IsOpenApiArray(this Type type)
             }
 
             return type.IsArrayType();
+        }
+
+        /// <summary>
+        /// Checks whether the given type is an array type that should be referenced or not, from the OpenAPI perspective.
+        /// </summary>
+        /// <param name="type"><see cref="Type"/> instance.</param>
+        /// <returns>Returns <c>True</c>, if the type is identified as array; otherwise returns <c>False</c>.</returns>
+        public static bool IsReferencedOpenApiArray(this Type type)
+        {
+            if (type.IsNullOrDefault())
+            {
+                return false;
+            }
+
+            return type.IsInheritedArrayType();
         }
 
         /// <summary>
@@ -460,9 +475,9 @@ public static Type GetUnderlyingType(this Type type)
                 underlyingType = nullableUnderlyingType;
             }
 
-            if (type.IsOpenApiArray())
+            if (type.IsOpenApiArray() || type.IsReferencedOpenApiArray())
             {
-                underlyingType = type.GetElementType() ?? type.GetGenericArguments()[0];
+                underlyingType = type.GetElementType() ?? type.GetArrayTypeGenericArgument();
             }
 
             if (type.IsOpenApiDictionary())
@@ -559,9 +574,9 @@ public static Type GetOpenApiSubType(this Type type)
                 return type.GetElementType();
             }
 
-            if (type.IsArrayType())
+            if (type.IsArrayType() || type.IsInheritedArrayType())
             {
-                return type.GetGenericArguments()[0];
+                return type.GetArrayTypeGenericArgument();
             }
 
             return null;
@@ -594,9 +609,9 @@ public static string GetOpenApiSubTypeName(this Type type, NamingStrategy naming
                 return namingStrategy.GetPropertyName(name, hasSpecifiedName: false);
             }
 
-            if (type.IsArrayType())
+            if (type.IsArrayType() || type.IsInheritedArrayType())
             {
-                var name = type.GetGenericArguments()[0].Name;
+                var name = type.GetArrayTypeGenericArgument().Name;
 
                 return namingStrategy.GetPropertyName(name, hasSpecifiedName: false);
             }
@@ -738,12 +753,40 @@ public static string GetTypeName(this Type type ,bool useFullName = false){
             var name = useFullName ? type.FullName : type.Name;
 
             return name;
-        }
+        }
+
+        private static Type GetArrayTypeGenericArgument(this Type type)
+        {
+            if (type.Name.Equals("IEnumerable`1", StringComparison.InvariantCultureIgnoreCase) == true)
+            {
+                return type.GetGenericArguments()[0];
+            }
 
+            return type.GetInterfaces()
+                .Where(p => p.IsInterface)
+                .Where(p => p.Name.Equals("IEnumerable`1", StringComparison.InvariantCultureIgnoreCase) == true)
+                .FirstOrDefault()?
+                .GetGenericArguments()[0];
+        }
 
         private static bool IsArrayType(this Type type)
         {
             var isArrayType = type.Name.Equals("String", StringComparison.InvariantCultureIgnoreCase) == false &&
+                              type.Namespace?.StartsWith("System") == true &&
+                              type.GetInterfaces()
+                                  .Where(p => p.IsInterface)
+                                  .Where(p => p.Name.Equals("IEnumerable", StringComparison.InvariantCultureIgnoreCase) == true)
+                                  .Any() &&
+                              type.IsJObjectType() == false &&
+                              type.IsDictionaryType() == false;
+
+            return isArrayType;
+        }
+
+        private static bool IsInheritedArrayType(this Type type)
+        {
+            var isArrayType = type.Name.Equals("String", StringComparison.InvariantCultureIgnoreCase) == false &&
+                              type.Namespace?.StartsWith("System") != true &&
                               type.GetInterfaces()
                                   .Where(p => p.IsInterface)
                                   .Where(p => p.Name.Equals("IEnumerable", StringComparison.InvariantCultureIgnoreCase) == true)

diff --git a/src/Microsoft.Azure.WebJobs.Extensions.OpenApi.Core/Visitors/ListObjectTypeVisitor.cs b/src/Microsoft.Azure.WebJobs.Extensions.OpenApi.Core/Visitors/ListObjectTypeVisitor.cs
@@ -26,7 +26,7 @@ public ListObjectTypeVisitor(VisitorCollection visitorCollection)
         /// <inheritdoc />
         public override bool IsVisitable(Type type)
         {
-            var isVisitable = this.IsVisitable(type, TypeCode.Object) && type.IsOpenApiArray();
+            var isVisitable = this.IsVisitable(type, TypeCode.Object) && (type.IsOpenApiArray() || type.IsReferencedOpenApiArray());
 
             return isVisitable;
         }
@@ -98,6 +98,23 @@ public override void Visit(IAcceptor acceptor, KeyValuePair<string, Type> type,
                                                     )
                                               .ToDictionary(p => p.Key, p => p.Value);
 
+            if (type.Value.IsReferencedOpenApiArray())
+            {
+                var reference = new OpenApiReference()
+                {
+                    Type = ReferenceType.Schema,
+                    Id = type.Value.GetOpenApiReferenceId(isDictionary: false, isList: false, namingStrategy, useFullName)
+                };
+
+                instance.Schemas[name].Title = type.Value.IsGenericType
+                    ? namingStrategy.GetPropertyName(type.Value.GetTypeName(useFullName).Split('`').First(), hasSpecifiedName: false) + "_" +
+                      string.Join("_",
+                          type.Value.GenericTypeArguments.Select(a => namingStrategy.GetPropertyName(a.GetTypeName(useFullName), false)))
+                    : namingStrategy.GetPropertyName(type.Value.GetTypeName(useFullName), hasSpecifiedName: false);
+                instance.Schemas[name].Type = "array";
+                instance.Schemas[name].Reference = reference;
+            }
+
             if (!schemasToBeAdded.Any())
             {
                 return;
@@ -125,6 +142,18 @@ public override bool IsParameterVisitable(Type type)
         /// <inheritdoc />
         public override OpenApiSchema ParameterVisit(Type type, NamingStrategy namingStrategy)
         {
+            if (type.IsReferencedOpenApiArray())
+            {
+                return new OpenApiSchema()
+                {
+                    Reference = new OpenApiReference()
+                    {
+                        Type = ReferenceType.Schema,
+                        Id = type.GetOpenApiReferenceId(isDictionary: false, isList: false, namingStrategy)
+                    }
+                };
+            }
+
             var schema = this.ParameterVisit(dataType: "array", dataFormat: null);
 
             var underlyingType = type.GetUnderlyingType();
@@ -146,8 +175,19 @@ public override bool IsPayloadVisitable(Type type)
         /// <inheritdoc />
         public override OpenApiSchema PayloadVisit(Type type, NamingStrategy namingStrategy, bool useFullName = false)
         {
-            var schema = this.PayloadVisit(dataType: "array", dataFormat: null);
+            if (type.IsReferencedOpenApiArray())
+            {
+                return new OpenApiSchema()
+                {
+                    Reference = new OpenApiReference()
+                    {
+                        Type = ReferenceType.Schema,
+                        Id = type.GetOpenApiReferenceId(isDictionary: false, isList: false, namingStrategy, useFullName)
+                    }
+                };
+            }
 
+            var schema = this.PayloadVisit(dataType: "array", dataFormat: null);
             // Gets the schema for the underlying type.
             var underlyingType = type.GetUnderlyingType();
             var items = this.VisitorCollection.PayloadVisit(underlyingType, namingStrategy, useFullName);

diff --git a/src/Microsoft.Azure.WebJobs.Extensions.OpenApi.Core/Visitors/ObjectTypeVisitor.cs b/src/Microsoft.Azure.WebJobs.Extensions.OpenApi.Core/Visitors/ObjectTypeVisitor.cs
@@ -226,7 +226,7 @@ private void ProcessProperties(IOpenApiSchemaAcceptor instance, string schemaNam
             // Adds schemas to the root.
             var schemasToBeAdded = subAcceptor.Schemas
                                               .Where(p => !instance.Schemas.Keys.Contains(p.Key))
-                                              .Where(p => p.Value.IsOpenApiSchemaObject())
+                                              .Where(p => p.Value.IsOpenApiSchemaObject() || (p.Value.IsOpenApiSchemaArray() && !p.Value.Title.IsNullOrWhiteSpace()))
                                               .GroupBy(p => p.Value.Title)
                                               .Select(p => p.First())
                                               .ToDictionary(p => p.Value.Title, p => p.Value);

diff --git a/....Azure.WebJobs.Extensions.OpenApi.Document.Tests/Get_ApplicationJson_ArrayObject_Tests.cs b/....Azure.WebJobs.Extensions.OpenApi.Document.Tests/Get_ApplicationJson_ArrayObject_Tests.cs
@@ -86,6 +86,18 @@ public void Given_OpenApiDocument_Then_It_Should_Return_ComponentSchemaProperty(
             value.Value<string>("type").Should().Be(propertyType);
         }
 
+        [DataTestMethod]
+        [DataRow("microsoft.Azure.WebJobs.Extensions.OpenApi.TestApp.Models.ArrayObjectModel", "object", "listStringObjectValue", "microsoft.Azure.WebJobs.Extensions.OpenApi.TestApp.Models.ListStringObjectModel")]
+        public void Given_OpenApiDocument_Then_It_Should_Return_ComponentSchemaPropertyWithReference(string @ref, string refType, string propertyName, string reference)
+        {
+            var properties = this._doc["components"]["schemas"][@ref]["properties"];
+
+            var value = properties[propertyName];
+
+            value.Should().NotBeNull();
+            value.Value<string>("$ref").Should().Be($"#/components/schemas/{reference}");
+        }
+
         [DataTestMethod]
         [DataRow("microsoft.Azure.WebJobs.Extensions.OpenApi.TestApp.Models.ArrayObjectModel", "object", "objectValue", "array", "object")]
         [DataRow("microsoft.Azure.WebJobs.Extensions.OpenApi.TestApp.Models.ArrayObjectModel", "object", "booleanValue", "array", "boolean")]

diff --git a/...rosoft.Azure.WebJobs.Extensions.OpenApi.Document.Tests/Get_ApplicationJson_Array_Tests.cs b/...rosoft.Azure.WebJobs.Extensions.OpenApi.Document.Tests/Get_ApplicationJson_Array_Tests.cs
@@ -32,6 +32,7 @@ public async Task Init()
         [DataRow("/get-applicationjson-int-array")]
         [DataRow("/get-applicationjson-bool-array")]
         [DataRow("/get-applicationjson-int-list")]
+        [DataRow("/get-applicationjson-named-list")]
         public void Given_OpenApiDocument_Then_It_Should_Return_Path(string path)
         {
             var paths = this._doc["paths"];
@@ -44,6 +45,7 @@ public void Given_OpenApiDocument_Then_It_Should_Return_Path(string path)
         [DataRow("/get-applicationjson-int-array", "get")]
         [DataRow("/get-applicationjson-bool-array", "get")]
         [DataRow("/get-applicationjson-int-list", "get")]
+        [DataRow("/get-applicationjson-named-list", "get")]
         public void Given_OpenApiDocument_Then_It_Should_Return_OperationType(string path, string operationType)
         {
             var pathItem = this._doc["paths"][path];
@@ -56,6 +58,7 @@ public void Given_OpenApiDocument_Then_It_Should_Return_OperationType(string pat
         [DataRow("/get-applicationjson-int-array", "get", "200")]
         [DataRow("/get-applicationjson-bool-array", "get", "200")]
         [DataRow("/get-applicationjson-int-list", "get", "200")]
+        [DataRow("/get-applicationjson-named-list", "get", "200")]
         public void Given_OpenApiDocument_Then_It_Should_Return_OperationResponse(string path, string operationType, string responseCode)
         {
             var responses = this._doc["paths"][path][operationType]["responses"];
@@ -68,6 +71,7 @@ public void Given_OpenApiDocument_Then_It_Should_Return_OperationResponse(string
         [DataRow("/get-applicationjson-int-array", "get", "200", "application/json")]
         [DataRow("/get-applicationjson-bool-array", "get", "200", "application/json")]
         [DataRow("/get-applicationjson-int-list", "get", "200", "application/json")]
+        [DataRow("/get-applicationjson-named-list", "get", "200", "application/json")]
         public void Given_OpenApiDocument_Then_It_Should_Return_OperationResponseContentType(string path, string operationType, string responseCode, string contentType)
         {
             var content = this._doc["paths"][path][operationType]["responses"][responseCode]["content"];
@@ -89,6 +93,29 @@ public void Given_OpenApiDocument_Then_It_Should_Return_OperationResponseContent
             schema.Value<string>("type").Should().Be(dataType);
         }
 
+        [DataTestMethod]
+        [DataRow("/get-applicationjson-named-list", "get", "200", "application/json", "microsoft.Azure.WebJobs.Extensions.OpenApi.TestApp.Models.ListStringObjectModel")]
+        public void Given_OpenApiDocument_Then_It_Should_Return_OperationResponseContentTypeSchemaWithReference(string path, string operationType, string responseCode, string contentType, string reference)
+        {
+            var content = this._doc["paths"][path][operationType]["responses"][responseCode]["content"];
+
+            var @ref = content[contentType]["schema"]["$ref"];
+
+            @ref.Value<string>().Should().Be($"#/components/schemas/{reference}");
+        }
+
+        [DataTestMethod]
+        [DataRow("microsoft.Azure.WebJobs.Extensions.OpenApi.TestApp.Models.ListStringObjectModel", "array")]
+        public void Given_OpenApiDocument_Then_It_Should_Return_ComponentSchemaProperty(string reference, string referenceType)
+        {
+            var properties = this._doc["components"]["schemas"][reference];
+
+            var type = properties["type"];
+
+            type.Should().NotBeNull();
+            type.Value<string>().Should().Be(referenceType);
+        }
+
         [DataTestMethod]
         [DataRow("/get-applicationjson-int-array", "get", "200", "application/json", "array", "integer", "int32")]
         [DataRow("/get-applicationjson-int-list", "get", "200", "application/json", "array", "integer", "int32")]
@@ -113,5 +140,13 @@ public void Given_OpenApiDocument_Then_It_Should_Return_OperationResponseContent
 
             items.Value<string>("type").Should().Be(itemType);
         }
+
+        [DataTestMethod]
+        [DataRow("microsoft.Azure.WebJobs.Extensions.OpenApi.TestApp.Models.ListStringObjectModel", "microsoft.Azure.WebJobs.Extensions.OpenApi.TestApp.Models.StringObjectModel")]
+        public void Given_OpenApiDocument_Then_It_Should_Return_ComponentSchemaPropertyItems(string reference, string itemRef)
+        {
+            var items = this._doc["components"]["schemas"][reference]["items"];
+            items.Value<string>("$ref").Should().Be($"#/components/schemas/{itemRef}");
+        }
     }
 }
diff --git a/...crosoft.Azure.WebJobs.Extensions.OpenApi.TestApp/Get_ApplicationJson_Array_HttpTrigger.cs b/...crosoft.Azure.WebJobs.Extensions.OpenApi.TestApp/Get_ApplicationJson_Array_HttpTrigger.cs
@@ -1,4 +1,6 @@
+using System.Collections;
 using System.Collections.Generic;
+using System.Linq;
 using System.Net;
 using System.Threading.Tasks;
 
@@ -14,15 +16,15 @@ namespace Microsoft.Azure.WebJobs.Extensions.OpenApi.TestApp
 {
     public static class Get_ApplicationJson_Array_HttpTrigger
     {
-        
+
         [FunctionName(nameof(Get_ApplicationJson_Array_HttpTrigger.Get_ApplicationJson_StringArray))]
         [OpenApiOperation(operationId: nameof(Get_ApplicationJson_Array_HttpTrigger.Get_ApplicationJson_StringArray), tags: new[] { "array" })]
         [OpenApiResponseWithBody(statusCode: HttpStatusCode.OK, contentType: "application/json", bodyType: typeof(string[]), Description = "The OK response")]
         public static async Task<IActionResult> Get_ApplicationJson_StringArray(
             [HttpTrigger(AuthorizationLevel.Anonymous, "GET", Route = "get-applicationjson-string-array")] HttpRequest req,
             ILogger log)
         {
-            var result  = new OkResult();
+            var result = new OkResult();
 
             return await Task.FromResult(result).ConfigureAwait(false);
         }
@@ -34,7 +36,7 @@ public static async Task<IActionResult> Get_ApplicationJson_IntArray(
             [HttpTrigger(AuthorizationLevel.Anonymous, "GET", Route = "get-applicationjson-int-array")] HttpRequest req,
             ILogger log)
         {
-            var result  = new OkResult();
+            var result = new OkResult();
 
             return await Task.FromResult(result).ConfigureAwait(false);
         }
@@ -46,7 +48,7 @@ public static async Task<IActionResult> Get_ApplicationJson_BoolArray(
             [HttpTrigger(AuthorizationLevel.Anonymous, "GET", Route = "get-applicationjson-bool-array")] HttpRequest req,
             ILogger log)
         {
-            var result  = new OkResult();
+            var result = new OkResult();
 
             return await Task.FromResult(result).ConfigureAwait(false);
         }
@@ -58,9 +60,21 @@ public static async Task<IActionResult> Get_ApplicationJson_IntList(
             [HttpTrigger(AuthorizationLevel.Anonymous, "GET", Route = "get-applicationjson-int-list")] HttpRequest req,
             ILogger log)
         {
-            var result  = new OkResult();
+            var result = new OkResult();
+
+            return await Task.FromResult(result).ConfigureAwait(false);
+        }
+
+        [FunctionName(nameof(Get_ApplicationJson_Array_HttpTrigger.Get_ApplicationJson_NamedList))]
+        [OpenApiOperation(operationId: nameof(Get_ApplicationJson_Array_HttpTrigger.Get_ApplicationJson_NamedList), tags: new[] { "array" })]
+        [OpenApiResponseWithBody(statusCode: HttpStatusCode.OK, contentType: "application/json", bodyType: typeof(ListStringObjectModel), Description = "The OK response")]
+        public static async Task<IActionResult> Get_ApplicationJson_NamedList(
+            [HttpTrigger(AuthorizationLevel.Anonymous, "GET", Route = "get-applicationjson-named-list")] HttpRequest req,
+            ILogger log)
+        {
+            var result = new OkResult();
 
             return await Task.FromResult(result).ConfigureAwait(false);
         }
     }
-}
+}
diff --git a/...integration/Microsoft.Azure.WebJobs.Extensions.OpenApi.TestApp/Models/ArrayObjectModel.cs b/...integration/Microsoft.Azure.WebJobs.Extensions.OpenApi.TestApp/Models/ArrayObjectModel.cs
@@ -12,7 +12,7 @@ public class ArrayObjectModel
         public IReadOnlyCollection<float> FloatValue { get; set; }
         public HashSet<decimal> DecimalValue { get; set; }
         public ISet<StringObjectModel> StringObjectValue { get; set; }
-
         public List<object[]> ObjectArrayValue { get; set; }
+        public ListStringObjectModel ListStringObjectValue { get; set; }
     }
 }
diff --git a/...ration/Microsoft.Azure.WebJobs.Extensions.OpenApi.TestApp/Models/ListStringObjectModel.cs b/...ration/Microsoft.Azure.WebJobs.Extensions.OpenApi.TestApp/Models/ListStringObjectModel.cs
@@ -0,0 +1,12 @@
+using System.Collections;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace Microsoft.Azure.WebJobs.Extensions.OpenApi.TestApp.Models;
+
+public class ListStringObjectModel : IEnumerable<StringObjectModel>
+{
+    public IEnumerator<StringObjectModel> GetEnumerator() => Enumerable.Empty<StringObjectModel>().GetEnumerator();
+
+    IEnumerator IEnumerable.GetEnumerator() => this.GetEnumerator();
+}