Testing an Extension

An Extension’s tests live in its repository’s tests/ directory, beside its package. They call its tools directly, with the settings they need, without installing the Extension, without the database, and without an LLM.

Testing a Tool

smarter.apps.llmtool.extension.testing has two helpers:

• tool_context() returns a tool call’s context, with the settings you give it.

• call_tool() calls a tool as the platform does: it validates the arguments, and returns an ExtensionToolError, or invalid arguments, as {"error": ...}. Unlike the platform, it lets any other exception propagate, so that your test sees it.

Mock the third-party services, so that the tests are fast and need no API keys:

tests/test_tools.py

"""Tests of the get_weather tool."""

import unittest
from unittest.mock import patch

from pydantic import SecretStr

from smarter.apps.llmtool.extension.testing import call_tool, tool_context
from weather.models import Conditions
from weather.services import Place, Weather
from weather.tools import GetWeather

CONTEXT = tool_context(
    "weather",
    google_maps_api_key=SecretStr("test-key"),
    weather_api_url="https://api.open-meteo.com/v1/forecast",
)


class TestGetWeather(unittest.TestCase):
    """Test get_weather, with its services mocked."""

    def test_weather(self):
        now = Conditions(time="2026-10-15 14:00", temperature=18.5, precipitation=0, wind_speed=12, cloud_cover=40)
        found = Weather(timezone="Europe/Paris", current=now, forecast=[now])
        with patch("weather.tools.geocode", return_value=Place("Paris, France", 48.85, 2.35)), patch(
            "weather.tools.weather", return_value=found
        ):
            result = call_tool(GetWeather, {"location": "Paris"}, CONTEXT)
        self.assertEqual(result["location"], "Paris, France")
        self.assertEqual(result["units"]["wind_speed"], "km/h")

    def test_unknown_place(self):
        with patch("weather.services.googlemaps.Client") as client:
            client.return_value.geocode.return_value = []
            result = call_tool(GetWeather, {"location": "Atlantis"}, CONTEXT)
        self.assertIn("Could not find Atlantis", result["error"])

    def test_invalid_arguments(self):
        self.assertIn("Invalid arguments", call_tool(GetWeather, {"unit": "KELVIN"})["error"])

Running the Tests

An Extension’s tests import Smarter, so they run in a Smarter development container, where manage.py test_extension puts the repository on sys.path and runs its tests/:

docker cp ../smarter-extension-weather smarter-app:/tmp/
docker exec smarter-app bash -c "cd /home/smarter_user/smarter && python manage.py test_extension /tmp/smarter-extension-weather"

Before you publish, also check the packaged Extension as the installer will, with manage.py validate_extension, and install it on your development platform to try it with an LLM. See Building an Extension.