Revert "test: 测试单元测试"

This reverts commit 83be2fa.

Author: ArgoZhang

src/BootstrapBlazor/Components/Upload/UploadPreviewList.razor.cs

@@ -262,5 +262,18 @@ private async Task OnClickCancel(UploadFile item)
         return builder.Build();
     }
 
-    private string? GetFileExtensions(string fileExtension) => FileIconFile;
+    private string? GetFileExtensions(string fileExtension) => fileExtension switch
+    {
+        ".csv" or ".xls" or ".xlsx" => FileIconExcel,
+        ".doc" or ".docx" or ".dot" or ".dotx" => FileIconDocx,
+        ".ppt" or ".pptx" => FileIconPPT,
+        ".wav" or ".mp3" => FileIconAudio,
+        ".mp4" or ".mov" or ".mkv" => FileIconVideo,
+        ".cs" or ".html" or ".vb" => FileIconCode,
+        ".pdf" => FileIconPdf,
+        ".zip" or ".rar" or ".iso" => FileIconZip,
+        ".txt" or ".log" => FileIconArchive,
+        ".jpg" or ".jpeg" or ".png" or ".bmp" or ".gif" => FileIconImage,
+        _ => FileIconFile
+    };
 }