fix(module: upload): Use System.IO.Path.GetExtension instead of Substring to support filenames without extensions (#3553) (#3554)

Co-authored-by: Noah Potash <noah.potash@outbreaklabs.com>

components/upload/UploadButton.razor.cs

@@ -137,7 +137,7 @@ namespace AntDesign.Internal
             foreach (var fileItem in flist)
             {
                 var fileName = fileItem.FileName;
-                fileItem.Ext = fileItem.FileName.Substring(fileName.LastIndexOf('.'));
+                fileItem.Ext = System.IO.Path.GetExtension(fileItem.FileName);
                 var id = Guid.NewGuid().ToString();
                 if (Upload.BeforeUpload != null && !Upload.BeforeUpload.Invoke(fileItem))
                 {

tests/AntDesign.Tests/Upload/UploadTests.razor

@@ -1,4 +1,7 @@
-@inherits AntDesignTestBase
+@using System.IO
+@using AngleSharp.Html.Dom
+@using AngleSharp.Io.Dom
+@inherits AntDesignTestBase
 @code {
     [Fact]
     public void Renders_basic_upload()
@@ -60,4 +63,21 @@
               </div>
           </span>);
     }
+
+    [Fact]
+    public async Task Handles_filenames_without_extension()
+    {
+        JSInterop.SetupVoid(JSInteropConstants.AddFileClickEventListener, _ => true);
+        JSInterop.SetupVoid(JSInteropConstants.UploadFile, _ => true).SetCanceled();
+        JSInterop.SetupVoid(JSInteropConstants.ClearFile, _ => true);
+
+        JSInterop.Setup<List<UploadFileItem>>(JSInteropConstants.GetFileInfo, _ => true).SetResult(new List<UploadFileItem> { new UploadFileItem { FileName = "test" } });
+
+        var cut = Context.Render(@<Upload>some content</Upload>);
+
+        var inputElement = ((AngleSharpWrappers.HtmlInputElementWrapper)cut.Find("input")).WrappedElement;
+        
+        Func<Task> act = () => inputElement.ChangeAsync(new ChangeEventArgs() { Value = "ignored" });
+        await act.Should().NotThrowAsync();
+    }
 }