feat: add NORTH_STAR.md and MVP core loop (Telegram bot + LLM + proposal generator)

tests/test_llm_client.py

@@ -0,0 +1,92 @@
+"""Tests for steward.llm.client."""
+
+from unittest.mock import AsyncMock, MagicMock, patch
+
+import pytest
+
+from steward.config import Settings
+from steward.llm.client import LLMClient
+
+
+def _make_settings(**kwargs) -> Settings:
+    defaults = dict(
+        telegram_bot_token="test-token",
+        openai_api_key="test-key",
+        openai_model="gpt-4o",
+        openai_system_prompt="You are Steward.",
+    )
+    defaults.update(kwargs)
+    return Settings(**defaults)
+
+
+@pytest.fixture
+def settings():
+    return _make_settings()
+
+
+@pytest.fixture
+def llm_client(settings):
+    return LLMClient(settings)
+
+
+@pytest.mark.asyncio
+async def test_chat_sends_correct_messages(llm_client):
+    """chat() should prepend the system prompt and append the user message."""
+    mock_response = MagicMock()
+    mock_response.choices[0].message.content = "Hello from the LLM!"
+
+    with patch.object(
+        llm_client._client.chat.completions,
+        "create",
+        new_callable=AsyncMock,
+        return_value=mock_response,
+    ) as mock_create:
+        result = await llm_client.chat("Hi there")
+
+    assert result == "Hello from the LLM!"
+    call_kwargs = mock_create.call_args.kwargs
+    messages = call_kwargs["messages"]
+    assert messages[0]["role"] == "system"
+    assert messages[-1]["role"] == "user"
+    assert messages[-1]["content"] == "Hi there"
+
+
+@pytest.mark.asyncio
+async def test_chat_with_history(llm_client):
+    """chat() should include history between system and user messages."""
+    history = [
+        {"role": "user", "content": "previous question"},
+        {"role": "assistant", "content": "previous answer"},
+    ]
+    mock_response = MagicMock()
+    mock_response.choices[0].message.content = "reply"
+
+    with patch.object(
+        llm_client._client.chat.completions,
+        "create",
+        new_callable=AsyncMock,
+        return_value=mock_response,
+    ) as mock_create:
+        await llm_client.chat("new question", history=history)
+
+    messages = mock_create.call_args.kwargs["messages"]
+    roles = [m["role"] for m in messages]
+    assert roles == ["system", "user", "assistant", "user"]
+
+
+@pytest.mark.asyncio
+async def test_chat_custom_system_prompt(llm_client):
+    """chat() should use a custom system prompt when provided."""
+    mock_response = MagicMock()
+    mock_response.choices[0].message.content = "ok"
+
+    with patch.object(
+        llm_client._client.chat.completions,
+        "create",
+        new_callable=AsyncMock,
+        return_value=mock_response,
+    ) as mock_create:
+        await llm_client.chat("msg", system_prompt="Custom prompt")
+
+    messages = mock_create.call_args.kwargs["messages"]
+    assert messages[0]["content"] == "Custom prompt"