Fix aria-describedby wiring and align abp-input/abp-select form-text rendering

- Move inputTag.Render after GetInfoAsHtml so aria-describedby reaches the final HTML
- Replace Attributes.Add with Attributes.SetAttribute for aria-describedby to avoid duplicates when [InputInfoText] and info="..." are both present
- Apply the same fixes to AbpInputTagHelperService for consistency
- Cover the [InputInfoText] attribute path with an additional test

framework/src/Volo.Abp.AspNetCore.Mvc.UI.Bootstrap/TagHelpers/Form/AbpInputTagHelperService.cs

@@ -88,10 +88,10 @@ public class AbpInputTagHelperService : AbpTagHelperService<AbpInputTagHelper>
         var (inputTag, isCheckBox) = await GetInputTagHelperOutputAsync(context, output);
         context.Items[nameof(IsOutputHidden)] = IsOutputHidden(inputTag);
 
-        var inputHtml = inputTag.Render(_encoder);
         var label = await GetLabelAsHtmlAsync(context, output, inputTag, isCheckBox);
         var info = GetInfoAsHtml(context, output, inputTag, isCheckBox);
         var validation = isCheckBox ? "" : await GetValidationAsHtmlAsync(context, output, inputTag);
+        var inputHtml = inputTag.Render(_encoder);
 
         return (GetContent(context, output, label, inputHtml, validation, info, isCheckBox), isCheckBox);
     }
@@ -267,7 +267,7 @@ public class AbpInputTagHelperService : AbpTagHelperService<AbpInputTagHelper>
 
         var infoText = _tagHelperLocalizer.GetLocalizedText(idAttr.Value + "InfoText", TagHelper.AspFor.ModelExplorer);
 
-        inputTagHelperOutput.Attributes.Add("aria-describedby", infoText);
+        inputTagHelperOutput.Attributes.SetAttribute("aria-describedby", infoText);
     }
 
     protected virtual bool IsInputCheckbox(TagHelperContext context, TagHelperOutput output, TagHelperAttributeList attributes)
@@ -363,7 +363,7 @@ public class AbpInputTagHelperService : AbpTagHelperService<AbpInputTagHelper>
         div.AddCssClass("form-text");
         div.InnerHtml.Append(localizedText);
 
-        inputTag.Attributes.Add("aria-describedby", idAttr?.Value + "InfoText");
+        inputTag.Attributes.SetAttribute("aria-describedby", idAttr?.Value + "InfoText");
 
         return div.ToHtmlString();
     }

framework/src/Volo.Abp.AspNetCore.Mvc.UI.Bootstrap/TagHelpers/Form/AbpSelectTagHelperService.cs

@@ -73,10 +73,10 @@ public class AbpSelectTagHelperService : AbpTagHelperService<AbpSelectTagHelper>
     protected virtual async Task<string> GetFormInputGroupAsHtmlAsync(TagHelperContext context, TagHelperOutput output, TagHelperContent childContent)
     {
         var selectTag = await GetSelectTagAsync(context, output, childContent);
-        var selectAsHtml = selectTag.Render(_encoder);
         var label = await GetLabelAsHtmlAsync(context, output, selectTag);
         var validation = await GetValidationAsHtmlAsync(context, output, selectTag);
         var infoText = GetInfoAsHtml(context, output, selectTag);
+        var selectAsHtml = selectTag.Render(_encoder);
 
         return TagHelper.FloatingLabel ? selectAsHtml + Environment.NewLine + label + Environment.NewLine + infoText + Environment.NewLine + validation :
                                          label + Environment.NewLine + selectAsHtml + Environment.NewLine + infoText + Environment.NewLine + validation;
@@ -224,7 +224,7 @@ public class AbpSelectTagHelperService : AbpTagHelperService<AbpSelectTagHelper>
 
         var infoText = _tagHelperLocalizer.GetLocalizedText(idAttr.Value + "InfoText", TagHelper.AspFor.ModelExplorer);
 
-        inputTagHelperOutput.Attributes.Add("aria-describedby", infoText);
+        inputTagHelperOutput.Attributes.SetAttribute("aria-describedby", infoText);
     }
 
     protected virtual string GetInfoAsHtml(TagHelperContext context, TagHelperOutput output, TagHelperOutput inputTag)
@@ -256,7 +256,7 @@ public class AbpSelectTagHelperService : AbpTagHelperService<AbpSelectTagHelper>
         div.AddCssClass("form-text");
         div.InnerHtml.Append(localizedText);
 
-        inputTag.Attributes.Add("aria-describedby", idAttr?.Value + "InfoText");
+        inputTag.Attributes.SetAttribute("aria-describedby", idAttr?.Value + "InfoText");
 
         return div.ToHtmlString();
     }

framework/test/Volo.Abp.AspNetCore.Mvc.UI.Tests/Volo/Abp/AspNetCore/Mvc/UI/Bootstrap/TagHelpers/Form/AbpSelectTagHelperService_Tests.cs

@@ -1,6 +1,7 @@
 #nullable enable
 
 using System.Collections.Generic;
+using System.Linq;
 using System.Reflection;
 using System.Text.Encodings.Web;
 using System.Threading.Tasks;
@@ -51,6 +52,30 @@ public class AbpSelectTagHelperService_Tests
         service.LastSelectTag.ShouldNotBeNull();
         service.LastSelectTag!.Attributes.ContainsName("aria-describedby").ShouldBeTrue();
         service.LastSelectTag.Attributes["aria-describedby"].Value.ToString().ShouldBe("TestSelectInfoText");
+        service.LastGroupHtml.ShouldContain("aria-describedby=\"TestSelectInfoText\"");
+    }
+
+    [Fact]
+    public async Task InputInfoText_attribute_should_render_info_text_with_single_aria_describedby()
+    {
+        var service = new TestAbpSelectTagHelperService();
+        var tagHelper = new AbpSelectTagHelper(service)
+        {
+            AspFor = CreateModelExpressionWithInputInfoText()
+        };
+
+        var output = CreateOutput();
+
+        await tagHelper.ProcessAsync(CreateContext(), output);
+
+        service.LastGroupHtml.ShouldContain("<div class=\"form-text\"");
+        service.LastGroupHtml.ShouldContain("Description from attribute");
+        service.LastGroupHtml.ShouldNotContain("<small");
+
+        service.LastSelectTag.ShouldNotBeNull();
+        var ariaDescribedby = service.LastSelectTag!.Attributes.Where(a => a.Name == "aria-describedby").ToList();
+        ariaDescribedby.Count.ShouldBe(1);
+        ariaDescribedby[0].Value.ToString().ShouldBe("TestSelectInfoText");
     }
 
     private static TagHelperContext CreateContext()
@@ -77,6 +102,21 @@ public class AbpSelectTagHelperService_Tests
             metadataProvider.GetModelExplorerForType(typeof(string), null));
     }
 
+    private static ModelExpression CreateModelExpressionWithInputInfoText()
+    {
+        var metadataProvider = new EmptyModelMetadataProvider();
+        var modelExplorer = metadataProvider
+            .GetModelExplorerForType(typeof(TestModelWithInputInfoText), null)
+            .GetExplorerForProperty(nameof(TestModelWithInputInfoText.TestSelect));
+        return new ModelExpression(nameof(TestModelWithInputInfoText.TestSelect), modelExplorer);
+    }
+
+    private class TestModelWithInputInfoText
+    {
+        [InputInfoText("Description from attribute")]
+        public string TestSelect { get; set; } = string.Empty;
+    }
+
     private sealed class TestAbpSelectTagHelperService : AbpSelectTagHelperService
     {
         public string LastGroupHtml { get; private set; } = string.Empty;
@@ -98,6 +138,8 @@ public class AbpSelectTagHelperService_Tests
                 TagMode = TagMode.StartTagAndEndTag
             };
 
+            AddInfoTextId(LastSelectTag);
+
             return Task.FromResult(LastSelectTag);
         }