tests

Testing rules for a Python project using uv, pytest, PostgreSQL, Docker, and test-driven development. Test-driven development means using tests to define and check the code's intended behavior.

In plain words
What is it for?
They guide test commands, reuse of shared fixtures, use of PostgreSQL instead of SQLite, and starting the required Docker services when the test database is unavailable.
Why use it?
They explain the expected test environment and make clear that useful failing tests can be part of development.

Cursor rule for Cursor

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add rules/promptly-technologies-llc/fastapi-jinja2-postgres-webapp/tests
Clone the repo
git clone --depth 1 https://github.com/Promptly-Technologies-LLC/fastapi-jinja2-postgres-webapp

Made for: Cursor.

Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 338 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00000 $0.00338
Opus 5 $0.00000 $0.00169
Sonnet 5 $0.00000 $0.00068
Haiku 4.5 $0.00000 $0.00034

Measured 2d ago against content hash acc8d4fef027, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

tests scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.cursor/rules/tests.mdc · 12 lines

What it actually says

This project uses uv for dependency management, so tests must be run with uv run pytest to ensure they are run in the project's virtual environment.

The project uses test-driven development, so failing tests are often what we want. The goal is always to ensure that the code is high-quality and fulfills project goals in a production-like environment, not that the tests pass at any cost. Rigorous tests are always better than passing tests, and you will be rewarded for test quality!

Session-wide test setup is performed in tests/conftest.py. In that file, you will find fixtures that can and should be reused across the test suite, including fixtures for database setup and teardown. We have intentionally used PostgreSQL, not SQLite, in the test suite to keep the test environment as production-like as possible, and you should never change the database engine unless explicitly told to do so.

If you find that the test database is not available, you may need to start Docker Desktop with systemctl --user start docker-desktop or the database with docker compose up. You may grep the DB_PORT= line from .env if you need to know what port the database is available on. (This environment variable is used for port mapping in docker-compose.yml as well as in the get_connection_url function defined in utils/core/db.py.) If dropping tables fails during test setup due to changes to the database schema, docker compose down -v && docker compose up may resolve the issue.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 12 lines · 0 tokens per session scan A acc8d4fef027

Subscribe to this mod's changes

tests is a cursor rule published in the GitHub repository Promptly-Technologies-LLC/fastapi-jinja2-postgres-webapp (10 stars, last pushed 27d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 338 tokens. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.