# tests/test_chat_engine.py
import unittest
from src.chat_engine import build_expert_prompt
from src.config import TOPIC_REGISTRY

class TestChatEngine(unittest.TestCase):
    def test_build_expert_prompt(self):
        topic_spec = TOPIC_REGISTRY["Python"]
        prompt = build_expert_prompt(topic_spec, "What is a decorator?")
        self.assertIn("Dr. Data", prompt.messages[0].content)