Update app.py

app.py

@@ -156,6 +156,8 @@ class InvoiceDuplicateDetector:
 detector = InvoiceDuplicateDetector()
 
 def upload_files(files):
+    if not files:
+        return "❌ No files selected."
     results = []
     for file in files:
         file_bytes = file.read() if hasattr(file, "read") else file.value
@@ -165,11 +167,13 @@ def upload_files(files):
     return "\n".join(results)
 
 def check_duplicates(file):
+    if not file:
+        return "❌ No file selected."
     file_bytes = file.read() if hasattr(file, "read") else file.value
     filename = file.name if hasattr(file, "name") else "uploaded"
     ok, result = detector.find_duplicates(file_bytes, filename)
     if not ok:
-        return result
+        return f"❌ {result}"
     if not result:
         return "✅ No duplicates found!"
     return "\n".join([f"🔁 {fname} — Similarity: {score:.2f}" for fname, score in result])