fix(binary): Add IFormFile support for binary in multipart requests

src/NSwag.CodeGeneration.CSharp.Tests/BinaryTests.cs

@@ -55,6 +55,64 @@ public async Task When_body_is_binary_then_stream_is_used_as_parameter_in_CSharp
             CSharpCompiler.AssertCompile(code);
         }
 
+        [Fact]
+        public async Task When_body_is_binary_then_IFormFile_is_used_as_part_of_object_in_CSharp_ASPNETCore()
+        {
+          var yaml = @"openapi: 3.0.0
+servers:
+  - url: https://www.example.com/
+info:
+  version: '2.0.0'
+  title: 'Test API'   
+paths:
+  /files:
+    post:
+      tags:
+        - Files
+      summary: 'Add File'
+      operationId: addFile
+      responses:
+        '200':
+          description: 'something'
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/FileToken'
+      requestBody:
+       content:
+         multipart/form-data:
+           schema:
+             type: object
+             properties:
+              file:
+                type: string
+                format: binary
+              name:
+                type: string
+components:
+  schemas:
+    FileToken:
+      type: object
+      required:
+        - fileId    
+      properties:  
+        fileId:
+          type: string
+          format: uuid";
+
+          var document = await OpenApiYamlDocument.FromYamlAsync(yaml);
+
+          // Act
+          CSharpControllerGeneratorSettings settings = new CSharpControllerGeneratorSettings();
+          settings.ControllerTarget = CSharpControllerTarget.AspNetCore;
+          var codeGenerator = new CSharpControllerGenerator(document, settings);
+          var code = codeGenerator.GenerateFile();
+
+          // Assert
+          await VerifyHelper.Verify(code);
+          CSharpCompiler.AssertCompile(code);
+        }
+
         [Fact]
         public async Task When_body_is_binary_then_IFormFile_is_used_as_parameter_in_CSharp_ASPNETCore()
         {

src/NSwag.CodeGeneration.CSharp.Tests/Snapshots/BinaryTests.When_body_is_binary_then_IFormFile_is_used_as_part_of_object_in_CSharp_ASPNETCore.verified.txt

@@ -0,0 +1,81 @@
+
+
+namespace MyNamespace
+{
+    using System = global::System;
+
+    public interface IController
+    {
+
+
+
+
+        System.Threading.Tasks.Task<FileToken> AddFileAsync(Microsoft.AspNetCore.Http.IFormFile file, string name);
+
+    }
+
+
+    public partial class Controller : Microsoft.AspNetCore.Mvc.ControllerBase
+    {
+        private IController _implementation;
+
+        public Controller(IController implementation)
+        {
+            _implementation = implementation;
+        }
+
+        [Microsoft.AspNetCore.Mvc.HttpPost, Microsoft.AspNetCore.Mvc.Route("files")]
+        public System.Threading.Tasks.Task<FileToken> AddFile(Microsoft.AspNetCore.Http.IFormFile file, string name)
+        {
+
+            return _implementation.AddFileAsync(file, name);
+        }
+
+    }
+
+    public partial class FileToken
+    {
+
+        [Newtonsoft.Json.JsonProperty("fileId", Required = Newtonsoft.Json.Required.Always)]
+        [System.ComponentModel.DataAnnotations.Required(AllowEmptyStrings = true)]
+        public System.Guid FileId { get; set; }
+
+        private System.Collections.Generic.IDictionary<string, object> _additionalProperties;
+
+        [Newtonsoft.Json.JsonExtensionData]
+        public System.Collections.Generic.IDictionary<string, object> AdditionalProperties
+        {
+            get { return _additionalProperties ?? (_additionalProperties = new System.Collections.Generic.Dictionary<string, object>()); }
+            set { _additionalProperties = value; }
+        }
+
+    }
+
+    public partial class FileParameter
+    {
+        public FileParameter(System.IO.Stream data)
+            : this (data, null, null)
+        {
+        }
+
+        public FileParameter(System.IO.Stream data, string fileName)
+            : this (data, fileName, null)
+        {
+        }
+
+        public FileParameter(System.IO.Stream data, string fileName, string contentType)
+        {
+            Data = data;
+            FileName = fileName;
+            ContentType = contentType;
+        }
+
+        public System.IO.Stream Data { get; private set; }
+
+        public string FileName { get; private set; }
+
+        public string ContentType { get; private set; }
+    }
+
+
+}

src/NSwag.CodeGeneration.CSharp/Models/CSharpOperationModel.cs

@@ -264,43 +264,57 @@ protected override string ResolveParameterType(OpenApiParameter parameter)
                 {
                     if (schema.Type == JsonObjectType.Array && schema.Item.IsBinary)
                     {
-                        return controllerSettings.ControllerTarget == CSharpControllerTarget.AspNetCore ?
-                            "System.Collections.Generic.ICollection<Microsoft.AspNetCore.Http.IFormFile>" :
-                            "System.Collections.Generic.ICollection<System.Web.HttpPostedFileBase>";
+                        return ResolveControllerBinaryCollectionType(controllerSettings);
                     }
-                    else
-                    {
-                        return controllerSettings.ControllerTarget == CSharpControllerTarget.AspNetCore ?
-                            "Microsoft.AspNetCore.Http.IFormFile" :
-                            "System.Web.HttpPostedFileBase";
-                    }
-                }
-                else
-                {
-                    return parameter.HasBinaryBodyWithMultipleMimeTypes ? "FileParameter" : "System.IO.Stream";
+
+                    return ResolveControllerBinarySingleType(controllerSettings);
                 }
+
+                return parameter.HasBinaryBodyWithMultipleMimeTypes ? "FileParameter" : "System.IO.Stream";
             }
 
             if (schema.Type == JsonObjectType.Array && (schema.Item?.IsBinary ?? false))
             {
-                return "System.Collections.Generic.IEnumerable<FileParameter>";
+                return _settings is CSharpControllerGeneratorSettings controllerSettings
+                    ? ResolveControllerBinaryCollectionType(controllerSettings)
+                    : "System.Collections.Generic.IEnumerable<FileParameter>";
             }
 
             if (schema.IsBinary)
             {
                 if (parameter.CollectionFormat == OpenApiParameterCollectionFormat.Multi && !schema.Type.HasFlag(JsonObjectType.Array))
                 {
-                    return "System.Collections.Generic.IEnumerable<FileParameter>";
+                    return _settings is CSharpControllerGeneratorSettings controllerSettings
+                        ? ResolveControllerBinaryCollectionType(controllerSettings)
+                        : "System.Collections.Generic.IEnumerable<FileParameter>";
+                }
+                else
+                {
+                    return _settings is CSharpControllerGeneratorSettings controllerSettings
+                        ? ResolveControllerBinarySingleType(controllerSettings)
+                        : "FileParameter";
                 }
-
-                return "FileParameter";
             }
 
             return base.ResolveParameterType(parameter)
                 .Replace(_settings.CSharpGeneratorSettings.ArrayType + "<", _settings.ParameterArrayType + "<")
                 .Replace(_settings.CSharpGeneratorSettings.DictionaryType + "<", _settings.ParameterDictionaryType + "<");
         }
 
+        private static string ResolveControllerBinarySingleType(CSharpControllerGeneratorSettings controllerSettings)
+        {
+            return controllerSettings.ControllerTarget == CSharpControllerTarget.AspNetCore ?
+                "Microsoft.AspNetCore.Http.IFormFile" :
+                "System.Web.HttpPostedFileBase";
+        }
+
+        private static string ResolveControllerBinaryCollectionType(CSharpControllerGeneratorSettings controllerSettings)
+        {
+            return controllerSettings.ControllerTarget == CSharpControllerTarget.AspNetCore ?
+                "System.Collections.Generic.ICollection<Microsoft.AspNetCore.Http.IFormFile>" :
+                "System.Collections.Generic.ICollection<System.Web.HttpPostedFileBase>";
+        }
+
         /// <summary>Creates the response model.</summary>
         /// <param name="operation">The operation.</param>
         /// <param name="statusCode">The status code.</param>