Added the possibility to specify the content type of the uploaded file

src/HotChocolate/AspNetCore/src/Transport.Abstractions/FileReference.cs

@@ -10,6 +10,12 @@ public sealed class FileReference
 {
     private readonly Func<Stream> _openRead;
 
+    /// <inheritdoc cref="FileReference(Stream,string,string)"/>
+    public FileReference(Stream stream, string fileName)
+        : this(stream, fileName, null)
+    {
+    }
+
     /// <summary>
     /// Creates a new instance of <see cref="FileReference" />
     /// </summary>
@@ -19,13 +25,16 @@ public sealed class FileReference
     /// <param name="fileName">
     /// The file name.
     /// </param>
+    /// <param name="contentType">
+    /// The file content type.
+    /// </param>
     /// <exception cref="ArgumentNullException">
     /// <paramref name="stream"/> is <c>null</c>.
     /// </exception>
     /// <exception cref="ArgumentException">
     /// <paramref name="fileName"/> is <c>null</c>, empty or white space.
     /// </exception>
-    public FileReference(Stream stream, string fileName)
+    public FileReference(Stream stream, string fileName, string? contentType)
     {
         ArgumentNullException.ThrowIfNull(stream);
 
@@ -38,6 +47,13 @@ public FileReference(Stream stream, string fileName)
 
         _openRead = () => stream;
         FileName = fileName;
+        ContentType = contentType;
+    }
+
+    /// <inheritdoc cref="FileReference(Func{Stream},string,string)"/>
+    public FileReference(Func<Stream> openRead, string fileName)
+        : this(openRead, fileName, null)
+    {
     }
 
     /// <summary>
@@ -49,13 +65,16 @@ public FileReference(Stream stream, string fileName)
     /// <param name="fileName">
     /// The file name.
     /// </param>
+    /// <param name="contentType">
+    /// The file content type.
+    /// </param>
     /// <exception cref="ArgumentException">
     /// <paramref name="fileName"/> is <c>null</c>, empty or white space.
     /// </exception>
     /// <exception cref="ArgumentNullException">
     /// <paramref name="openRead"/> is <c>null</c>.
     /// </exception>
-    public FileReference(Func<Stream> openRead, string fileName)
+    public FileReference(Func<Stream> openRead, string fileName, string? contentType)
     {
         if (string.IsNullOrWhiteSpace(fileName))
         {
@@ -66,13 +85,19 @@ public FileReference(Func<Stream> openRead, string fileName)
 
         _openRead = openRead ?? throw new ArgumentNullException(nameof(openRead));
         FileName = fileName;
+        ContentType = contentType;
     }
 
     /// <summary>
-    /// The file name eg. <c>foo.txt</c>.
+    /// The file name e.g. <c>"foo.txt"</c>.
     /// </summary>
     public string FileName { get; }
 
+    /// <summary>
+    /// The content type of the file e.g. <c>"application/pdf"</c>.
+    /// </summary>
+    public string? ContentType { get; }
+
     /// <summary>
     /// Opens the file stream.
     /// </summary>

src/HotChocolate/AspNetCore/src/Transport.Http/DefaultGraphQLHttpClient.cs

@@ -215,8 +215,13 @@ private static HttpContent CreateMultipartContent(
 
         foreach (var fileInfo in fileInfos)
         {
-            var file = new StreamContent(fileInfo.File.OpenRead());
-            form.Add(file, fileInfo.Name, fileInfo.File.FileName);
+            var fileContent = new StreamContent(fileInfo.File.OpenRead());
+            if (!string.IsNullOrEmpty(fileInfo.File.ContentType))
+            {
+                fileContent.Headers.ContentType = new MediaTypeHeaderValue(fileInfo.File.ContentType);
+            }
+
+            form.Add(fileContent, fileInfo.Name, fileInfo.File.FileName);
         }
 
         return form;

src/HotChocolate/AspNetCore/test/Transport.Http.Tests/GraphQLHttpClientTests.cs

@@ -1,4 +1,5 @@
 using System.Net;
+using System.Text;
 using System.Text.Json;
 using HotChocolate.AspNetCore.Tests.Utilities;
 using HotChocolate.Language;
@@ -881,29 +882,39 @@ public async Task Get_Subscription_Over_SSE_With_Errors()
         await snapshot.MatchMarkdownAsync(cts.Token);
     }
 
-    [Fact]
-    public async Task Post_GraphQL_FileUpload()
+    [Theory]
+    [InlineData((string?)null)]
+    [InlineData("application/pdf")]
+    public async Task Post_GraphQL_FileUpload(string? contentType)
     {
         // arrange
         using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(5000));
-        using var testServer = CreateStarWarsServer();
-        var httpClient = testServer.CreateClient();
+        var server = CreateStarWarsServer(
+            configureServices: s => s
+                .AddGraphQLServer("test")
+                .AddType<UploadType>()
+                .AddQueryType<UploadTestQuery>());
+        var httpClient = server.CreateClient();
         var client = new DefaultGraphQLHttpClient(httpClient);
 
         var stream = new MemoryStream("abc"u8.ToArray());
 
         var operation = new OperationRequest(
             """
             query ($upload: Upload!) {
-              singleUpload(file: $upload)
+              singleInfoUpload(file: $upload) {
+                name
+                content
+                contentType
+              }
             }
             """,
             variables: new Dictionary<string, object?>
             {
-                ["upload"] = new FileReference(() => stream, "test.txt")
+                ["upload"] = new FileReference(() => stream, "test.txt", contentType)
             });
 
-        var requestUri = new Uri(CreateUrl("/upload"));
+        var requestUri = new Uri(CreateUrl("/test"));
 
         var request = new GraphQLHttpRequest(operation, requestUri)
         {
@@ -917,10 +928,14 @@ public async Task Post_GraphQL_FileUpload()
         // assert
         using var body = await response.ReadAsResultAsync(cts.Token);
         body.MatchInlineSnapshot(
-            """
+            $$$"""
             {
               "data": {
-                "singleUpload": "abc"
+                "singleInfoUpload": {
+                  "name": "test.txt",
+                  "content": "abc",
+                  "contentType": "{{{contentType}}}"
+                }
               }
             }
             """);
@@ -1006,4 +1021,26 @@ public async IAsyncEnumerable<string> CreateStream()
         public string OnError([EventMessage] string message)
             => message;
     }
+
+    public class UploadTestQuery
+    {
+        public async Task<FileInfoOutput> SingleInfoUpload(IFile file)
+        {
+            await using var stream = file.OpenReadStream();
+            using var sr = new StreamReader(stream, Encoding.UTF8);
+            return new FileInfoOutput
+            {
+                Content = await sr.ReadToEndAsync(),
+                ContentType = file.ContentType ?? string.Empty,
+                Name = file.Name
+            };
+        }
+
+        public class FileInfoOutput
+        {
+            public string? Content { get; init; }
+            public string? ContentType { get; init; }
+            public string? Name { get; init; }
+        }
+    }
 }

src/StrawberryShake/Client/src/Core/Upload.cs

@@ -5,13 +5,20 @@ namespace StrawberryShake;
 /// </summary>
 public readonly struct Upload
 {
+    /// <inheritdoc cref="Upload(Stream, string, string?)"/>
+    public Upload(Stream content, string fileName)
+        : this(content, fileName, null)
+    {
+    }
+
     /// <summary>
-    /// Creates a new instance of Upload
+    /// Creates a new instance of the Upload-scalar.
     /// </summary>
-    public Upload(Stream content, string fileName)
+    public Upload(Stream content, string fileName, string? contentType)
     {
         Content = content;
         FileName = fileName;
+        ContentType = contentType;
     }
 
     /// <summary>
@@ -23,4 +30,12 @@ public Upload(Stream content, string fileName)
     /// The name of the file
     /// </summary>
     public string FileName { get; }
+
+    /// <summary>
+    /// The optional MIME type of the file.
+    /// </summary>
+    /// <remarks>
+    /// If specified, this value is applied as the HTTP Content-Type header.
+    /// </remarks>
+    public string? ContentType { get; }
 }

src/StrawberryShake/Client/src/Transport.Http/HttpConnection.cs

@@ -241,7 +241,7 @@ private static void MapVariables(List<object?> variables)
             {
                 case Dictionary<string, object> result:
                     result[currentPath] =
-                        new FileReference(upload.Value.Content, upload.Value.FileName);
+                        new FileReference(upload.Value.Content, upload.Value.FileName, upload.Value.ContentType);
                     break;
 
                 case List<object> array:
@@ -258,7 +258,7 @@ private static void MapVariables(List<object?> variables)
                     }
 
                     array[arrayIndex] =
-                        new FileReference(upload.Value.Content, upload.Value.FileName);
+                        new FileReference(upload.Value.Content, upload.Value.FileName, upload.Value.ContentType);
 
                     break;
 

src/StrawberryShake/Client/src/Transport.InMemory/DependencyInjection/InMemoryClient.cs

@@ -129,7 +129,7 @@ await interceptor
             default:
                 if (fileValue is Upload upload)
                 {
-                    return new StreamFile(upload.FileName, () => upload.Content);
+                    return new StreamFile(upload.FileName, () => upload.Content, null, upload.ContentType);
                 }
 
                 return variables;