fix: satisfy mypy and ruff for chat completions API usage

Use ChatCompletionMessageParam and ResponseFormat for OpenAI client calls;
apply ruff formatting to tests/test_pipeline.py for CI.

Made-with: Cursor

Author: ringochen06

src/regbot/compliance.py

@@ -11,6 +11,8 @@
     OpenAI,
     RateLimitError,
 )
+from openai.types.chat import ChatCompletionMessageParam
+from openai.types.chat.completion_create_params import ResponseFormat
 
 from src.regbot.config import (
     DEFAULT_LLM_MODEL,
@@ -237,16 +239,17 @@ def analyze_compliance(
     while attempts < max_attempts:
         attempts += 1
         user = base_user + suffix
-        messages = [
+        messages: list[ChatCompletionMessageParam] = [
             {"role": "system", "content": system},
             {"role": "user", "content": user},
         ]
+        json_mode: ResponseFormat = {"type": "json_object"}
         try:
             try:
                 resp = client.chat.completions.create(
                     model=model_name,
                     messages=messages,
-                    response_format={"type": "json_object"},
+                    response_format=json_mode,
                     temperature=0.2,
                 )
             except BadRequestError:

tests/test_pipeline.py

@@ -43,9 +43,7 @@ def tearDown(self) -> None:
 
     @patch("src.regbot.retrieval.load_sentence_transformer")
     @patch("src.regbot.ingestion.load_sentence_transformer")
-    def test_ingest_retrieve_check_smoke(
-        self, mock_ingest_load, mock_retrieve_load
-    ) -> None:
+    def test_ingest_retrieve_check_smoke(self, mock_ingest_load, mock_retrieve_load) -> None:
         fake = _FakeSentenceTransformer()
         mock_ingest_load.return_value = fake
         mock_retrieve_load.return_value = fake