Define UploadPathHelper.TemporaryFilePrefix and UploadPathHelper.IsTemporaryFile and use them instead of hardcoding temporary/

Author: volkanceylan

src/services/Upload/DefaultUploadProcessor.cs

@@ -57,7 +57,7 @@ public virtual ProcessedUploadInfo Process(System.IO.Stream stream, string filen
 
         UploadPathHelper.CheckFileNameSecurity(filename);
 
-        bool isExistingTemporary = filename.StartsWith("temporary/", StringComparison.Ordinal) &&
+        bool isExistingTemporary = UploadPathHelper.IsTemporaryFile(filename) &&
             uploadStorage.FileExists(filename);
 
         if (!isExistingTemporary)
@@ -86,7 +86,7 @@ public virtual ProcessedUploadInfo Process(System.IO.Stream stream, string filen
 
                     if (!isExistingTemporary)
                     {
-                        var basePath = "temporary/" + Guid.NewGuid().ToString("N");
+                        var basePath = UploadPathHelper.TemporaryFilePrefix + Guid.NewGuid().ToString("N");
                         stream.Seek(0, System.IO.SeekOrigin.Begin);
                         result.TemporaryFile = uploadStorage.WriteFile(basePath + System.IO.Path.GetExtension(filename),
                             stream, OverwriteOption.Disallowed);

src/services/Upload/UploadPathHelper.cs

@@ -113,4 +113,22 @@ public static string FindAvailableName(string path, Func<string, bool> exists)
 
         return path;
     }
+
+    /// <summary>
+    /// Represents the prefix used to identify temporary upload files.
+    /// </summary>
+    /// <remarks>Use this constant to distinguish files that are stored temporarily during the upload process.
+    /// Files with this prefix are typically subject to cleanup or special handling.</remarks>
+    public const string TemporaryFilePrefix = "temporary/";
+
+    /// <summary>
+    /// Determines whether the specified file name represents a temporary upload file.
+    /// </summary>
+    /// <param name="fileName">The name of the file to evaluate. Can be null or empty.</param>
+    /// <returns>true if the file name is not null or empty and indicates a temporary upload file; otherwise, false.</returns>
+    public static bool IsTemporaryFile(string fileName)
+    {
+        return !string.IsNullOrEmpty(fileName) &&
+            fileName.StartsWith(TemporaryFilePrefix, StringComparison.Ordinal);
+    }
 }

src/web/Upload/DefaultUploadStorage.cs

@@ -45,9 +45,9 @@ public DefaultUploadStorage(IOptions<UploadSettings> options, IWebHostEnvironmen
             new TempUploadStorage(new DiskUploadStorageOptions
             {
                 RootPath = Path.Combine(path, "temporary"),
-                RootUrl = UriHelper.Combine(opt.Url, "temporary/")
+                RootUrl = UriHelper.Combine(opt.Url, UploadPathHelper.TemporaryFilePrefix)
             }, fileSystem),
-            "temporary/");
+            UploadPathHelper.TemporaryFilePrefix);
     }
 
     /// <inheritdoc/>

src/web/Upload/FileUploadBehavior.cs

@@ -360,7 +360,7 @@ private CopyTemporaryFileResult CopyTemporaryFile(ISaveRequestHandler handler, I
         if (string.IsNullOrEmpty(temporaryFile))
             throw new ArgumentNullException(nameof(temporaryFile));
 
-        if (!temporaryFile.StartsWith("temporary/", StringComparison.OrdinalIgnoreCase))
+        if (!UploadPathHelper.IsTemporaryFile(temporaryFile))
             throw new InvalidOperationException("For security reasons, only temporary files can be used in uploads!");
 
         UploadPathHelper.CheckFileNameSecurity(temporaryFile);