pytest

pytest is a cursor rule for Cursor from sanjeed5/awesome-cursor-rules-mdc. It costs 1,879 tokens per session, scanned A, original, CC0-1.0.

A set of coding guidelines for writing Python tests with pytest, a tool for checking that software behaves as expected. It covers project layout, test file naming, imports, and maintainable test organisation.

In plain words
What is it for?
Use it when setting up a Python project's src layout, naming test files, organising test packages, and writing pytest test functions.
Why use it?
It helps tests run against the intended installed package and reduces import, naming, and structure problems as the test suite grows.

Cursor rule for Cursor

Written for Cursor: a Cursor rule (.mdc).

Good fit Use it when setting up a Python project's src layout, naming test files, organising test packages, and writing pytest test functions.

Compare 6 cursor rules from other repositories ↓
Install with agentmods
npx agentmods add rules/sanjeed5/awesome-cursor-rules-mdc/pytest
About the project

awesome-cursor-rules-mdc is a generator that creates Cursor MDC rule files from structured library information, using semantic search and language models to gather and organize guidance. Developers use it to produce reusable rules for libraries in Cursor, and the catalogue includes 200 of those rules.

sanjeed5/awesome-cursor-rules-mdc · 3,571 stars · on GitHub

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.

Clone the repo
git clone --depth 1 https://github.com/sanjeed5/awesome-cursor-rules-mdc

Made for: Cursor.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for pytest

README.md
[![agentmods](https://agentmods.dev/badge/rules/sanjeed5/awesome-cursor-rules-mdc/pytest.svg)](https://agentmods.dev/rules/sanjeed5/awesome-cursor-rules-mdc/pytest)
Your own site
<a href="https://agentmods.dev/rules/sanjeed5/awesome-cursor-rules-mdc/pytest"><img src="https://agentmods.dev/badge/rules/sanjeed5/awesome-cursor-rules-mdc/pytest.svg" alt="Measured on agentmods" height="20"></a>
Per session 1,879 This file is loaded in full into every session.
When invoked 1,879 The same file — it is already loaded in full.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.01879 $0.01879
Opus 5 $0.00940 $0.00940
Sonnet 5 $0.00376 $0.00376
Haiku 4.5 $0.00188 $0.00188

Measured 3d ago against content hash d5f01ee429e9, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

pytest 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 3d 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.

rules-mdc/pytest.mdc · 263 lines

How it starts

The opening of the file, as written. The whole thing — 263 lines — stays where its author put it; the contents beside it link to each section on GitHub.

pytest Best Practices

This document outlines our team's standard for writing pytest tests. Adhering to these guidelines ensures our test suite is fast, reliable, and easy to maintain, integrating seamlessly into our CI/CD pipelines.

1. Code Organization & Structure

1.1 Project Layout

Always use the src/ layout for your project. This prevents common import pitfalls and ensures tests run against the installed package, not local source.

✅ GOOD:

.
├── pyproject.toml
├── src/
│   └── mypackage/
│       ├── __init__.py
│       └── module.py
└── tests/
    ├── __init__.py
    └── test_module.py

❌ BAD:

.
├── pyproject.toml
├── mypackage/ # Top-level package
│   ├── __init__.py
│   └── module.py
└── tests/
    └── test_module.py

1.2 Test File Naming

Name test files test_*.py or *_test.py. We prefer test_*.py. Place __init__.py files in tests/ and its subdirectories to treat them as Python packages, enabling structured imports and avoiding name collisions.

✅ GOOD:

# tests/test_my_feature.py
from mypackage.module import my_function

def test_my_function_returns_expected_value():
    assert my_function() == "expected"

1.3 Test Naming Conventions

Prefix test functions and methods with test_. For classes, prefix with Test. Use descriptive names that read like sentences.

✅ GOOD:

def test_user_can_be_created_with_valid_email():
    # ...
    pass

class TestUserService:
    def test_get_user_by_id_returns_correct_user():
        # ...
        pass

❌ BAD:

def create_user(): # Not discovered by pytest
    pass

def test_create_user_and_email(): # Tests multiple things
    pass

class UserServiceTest: # Incorrect class prefix
    pass

2. Common Patterns & Anti-patterns

2.1 Single Assert Per Test

Each test should verify one specific behavior. This improves readability and simplifies debugging.

✅ GOOD:

def test_user_creation_sets_email():
    user = create_user("[email protected]")
    assert user.email == "[email protected]"

def test_user_creation_sends_welcome_email():
    user = create_user("[email protected]")
    assert email_service.last_sent_email == "[email protected]"

Read the full file on GitHub · 263 lines

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. 3d ago First seen · 263 lines · 1,879 tokens per session scan A d5f01ee429e9

Subscribe to this mod's changes

pytest is a cursor rule published in the GitHub repository sanjeed5/awesome-cursor-rules-mdc (3,571 stars, last pushed 3mo ago), licensed CC0-1.0. It adds 1,879 tokens to every session, about $0.0094 per session on Opus 5. 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 2026-09-03.