llm-ide-rules: Instructions file for GitHub Copilot

Pytest Tests

• Look first to app.factories.* instead of app.models.* to generate any required database state
  • For example, to create and persist a Distribution record DistributionFactory.save()
  • If a factory doesn't exist for the model you are working with, create one.
  • You can customize one or more params in a factory using DistributionFactory.save(host="custom_host.com)
• Use faker factory to generate emails, etc.
• Do not mock or patch unless I instruct you to. Test as much of the application stack as possible in each test.
• If you get lazy attribute errors, or need a database session to share across logic, use the db_session fixture to fix the issue.
  • Note that when writing route tests a db_session is not needed for the logic inside of the route.
• When testing Stripe, use the sandbox API. Never mock out Stripe interactions unless explicitly told to.
• Omit obvious docstrs and comments. Add comments for non-obvious but easy-to-miss lines that are key to what the test is checking.
• Do not add multiple tests for a one-line change.
• If test state setup requires more than three distinct factories, you should probably create a new factory to represent this particular state.
• Add pre-condition assertions when setup is load-bearing.
• If a monkeypatch is truly needed, a one-line comment on why. Prefer full-stack testing over mocking.

Example Test

Below is an example test, you'll notice the following:

• Docstr is omitted since the purpose of the test is obvious
• Comment about the county is added since it's the main point of the test
• Newline between test setup, functionality under test, and assertions against result
• api_app_url_path_for helper is used instead of hardcoded routes

from app.generated.fastapi_typed_routes import api_app_url_path_for
import json


def test_calculate_quote_unknown_county(client):
    payload = {
        "subscriber": {"age": 35, "gender": "M"},
        # fake county to ensure error is thrown
        "county": "NotACounty",
    }

    response = client.post(
        api_app_url_path_for("composite_quote"),
        json=payload,
    )

    assert_status(response, status.HTTP_422_UNPROCESSABLE_CONTENT)