Update web/src/App.tsx

web/src/App.tsx

@@ -663,6 +663,9 @@ function App() {
 
   const handleStartQuiz = () => handleNextQuestion();
 
+  // =========================
+  // ✅ File Upload (FIXED)
+  // =========================
   const handleFileUpload = (files: File[]) => {
     const newFiles: UploadedFile[] = files.map((file) => ({ file, type: "other" as FileType }));
     setUploadedFiles((prev) => [...prev, ...newFiles]);
@@ -672,17 +675,26 @@ function App() {
     setUploadedFiles((prev) => prev.filter((_, i) => i !== index));
   };
 
+  // ✅ CRITICAL FIX:
+  // - use functional setState to avoid stale closure
+  // - do NOT overwrite newly-added files
+  // - safely pick the target file inside the updater
   const handleFileTypeChange = async (index: number, type: FileType) => {
     if (!user) return;
 
-    const next = uploadedFiles.map((f, i) => (i === index ? { ...f, type } : f));
-    setUploadedFiles(next);
+    let targetFile: File | undefined;
+
+    setUploadedFiles((prev) => {
+      if (index < 0 || index >= prev.length) return prev;
+
+      const next = prev.map((f, i) => (i === index ? { ...f, type } : f));
+      targetFile = next[index]?.file;
+      return next;
+    });
 
-    const target = next[index];
-    const file = target?.file;
-    if (!file) return;
+    if (!targetFile) return;
 
-    const fp = `${file.name}::${file.size}::${file.lastModified}`;
+    const fp = `${targetFile.name}::${targetFile.size}::${targetFile.lastModified}`;
     if (uploadedFingerprintsRef.current.has(fp)) return;
     uploadedFingerprintsRef.current.add(fp);
 
@@ -690,7 +702,7 @@ function App() {
       await apiUpload({
         user_id: user.email,
         doc_type: DOC_TYPE_MAP[type] || "Other Course Document",
-        file,
+        file: targetFile,
       });
       toast.success("File uploaded to backend");
     } catch (e: any) {