Skip dataType override for IRemoteStreamContent in jQuery proxy generator

framework/src/Volo.Abp.Http/Volo/Abp/Http/ProxyScripting/Generators/JQuery/JQueryProxyScriptGenerator.cs

@@ -146,6 +146,15 @@ public class JQueryProxyScriptGenerator : IProxyScriptGenerator, ITransientDepen
 
     private static string GetJQueryDataTypeAndAcceptOverride(ActionApiDescriptionModel action)
     {
+        // jQuery doesn't natively support binary downloads, so don't override
+        // dataType/Accept for remote stream returns — letting the server pick the
+        // formatter naturally avoids forcing JSON metadata in place of the binary
+        // payload (which would re-introduce the original IRemoteStreamContent bug).
+        if (action.ReturnValue.IsRemoteStream)
+        {
+            return string.Empty;
+        }
+
         var contentTypes = action.ReturnValue.ContentTypes;
         var isStringReturn = action.ReturnValue.Type == ReturnValueApiDescriptionModel.Create(typeof(string)).Type;
 

framework/test/Volo.Abp.Http.Tests/Volo/Abp/Http/ProxyScripting/Generators/JQuery/JQueryProxyScriptGenerator_ContentTypes_Tests.cs

@@ -93,7 +93,27 @@ public class JQueryProxyScriptGenerator_ContentTypes_Tests
         script.ShouldContain("dataType: 'json'");
     }
 
-    private static ApplicationApiDescriptionModel BuildAppModel(string returnType, IList<string>? contentTypes)
+    [Fact]
+    public void IsRemoteStream_Should_Skip_DataType_Override_To_Avoid_JSON_Metadata_Regression()
+    {
+        // For IRemoteStreamContent returns the API definition still advertises
+        // application/json (server-side default formatter list). The generator
+        // MUST NOT force dataType:'json' + Accept:'application/json' for these —
+        // doing so makes the server JSON-serialise the IRemoteStreamContent object
+        // and re-introduces the original IRemoteStreamContent bug. jQuery doesn't
+        // natively support binary downloads, so we let the legacy behavior stand.
+        var model = BuildAppModel(
+            returnType: "Volo.Abp.Content.IRemoteStreamContent",
+            contentTypes: new[] { "text/plain", "application/json", "text/json" },
+            isRemoteStream: true);
+
+        var script = _generator.CreateScript(model);
+
+        script.ShouldNotContain("dataType: 'json'");
+        script.ShouldNotContain("Accept: 'application/json'");
+    }
+
+    private static ApplicationApiDescriptionModel BuildAppModel(string returnType, IList<string>? contentTypes, bool isRemoteStream = false)
     {
         var model = ApplicationApiDescriptionModel.Create();
         var module = model.GetOrAddModule("app", "Default");
@@ -119,6 +139,7 @@ public class JQueryProxyScriptGenerator_ContentTypes_Tests
                 Type = returnType,
                 TypeSimple = returnType,
                 ContentTypes = contentTypes,
+                IsRemoteStream = isRemoteStream,
             },
             AuthorizeDatas = new List<AuthorizeDataApiDescriptionModel>(),
         };