fix

src/lib/testService.js

@@ -79,10 +79,40 @@ Options must be prefixed "A) ", "B) ", "C) ", "D) ". Make questions specific and
   });
 
   const emitted = result.toolUses[0]?.input;
-  if (!emitted?.questions?.length) {
-    throw new Error(`Could not generate questions for ${topic.label}`);
+  if (!emitted) {
+    throw new Error(`LLM did not emit tool output for ${topic.label}`);
   }
-  return emitted.questions;
+
+  // Handle different shapes the LLM might return:
+  // 1. { questions: [...] }  — expected
+  // 2. [...]                 — model returned array directly
+  // 3. { questions: { ... } } — model wrapped single question in object
+  let questions;
+  if (Array.isArray(emitted.questions)) {
+    questions = emitted.questions;
+  } else if (Array.isArray(emitted)) {
+    questions = emitted;
+  } else if (emitted.questions && typeof emitted.questions === 'object') {
+    // Single question wrapped as object instead of array
+    questions = [emitted.questions];
+  } else {
+    throw new Error(`Unexpected quiz output shape for ${topic.label}`);
+  }
+
+  if (!questions.length) {
+    throw new Error(`No questions generated for ${topic.label}`);
+  }
+
+  // Ensure each question has required fields (fill in defaults for missing ones)
+  return questions.map((q, i) => ({
+    id: q.id || `gen-${i}-${Math.random().toString(36).slice(2, 8)}`,
+    question: q.question || '',
+    topicLabel: q.topicLabel || topic.label,
+    options: Array.isArray(q.options) ? q.options.slice(0, 4) : [],
+    correctIndex: typeof q.correctIndex === 'number' ? q.correctIndex : 0,
+    explanation: q.explanation || 'No explanation provided.',
+    difficulty: q.difficulty || 'medium',
+  })).filter(q => q.question && q.options.length === 4);
 }
 
 async function selectTestTopics(userId, isoWeekNumber) {