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.cursor/rules/testing.mdc

Cursor testing rule for Python ML

A Cursor `.mdc` rule can attach only when you touch tests. This variant keeps testing policy out of the always-on project rule so day-to-day edits stay quieter. This copy is written for a Python ML project. This repository is a Python data or machine-learning project. Training code does not see the test split. Notebooks are for exploration. Reusable logic lives in importable modules.

The example uses a balanced, readable style, pragmatic tests, and comments only where the intent is not obvious. Open the generator to make the agent stricter, switch to test-first, quiet the comments, or pick a different file.

The example assumes Python for data or ML work. It does not assume PyTorch versus scikit-learn, or a particular experiment tracker. Use the libraries already in the environment.

Customize in the generatorBrowse the library

Example file

Balanced strictness, readable style, pragmatic tests. Download name: testing.mdc

---
description: "Testing rules for a Python ML repository"
globs: "**/test_*.py"
alwaysApply: false
---

# Testing rules

Attach these rules when editing tests in this Python ML repository.
The always-on project rule still lives in `.cursor/rules/project.mdc`. This file does not repeat it.

## Stack

This repository is a Python data or machine-learning project. Training code does not see the test split. Notebooks are for exploration. Reusable logic lives in importable modules.

## Commands

- Tests: `pytest`
- Lint: `ruff check .`
- Train: `Run the project's training entry point, not a notebook cell`

Use the script the repo already defines when it differs from the command above.

## Testing

Add or update tests when behavior changes.

Test the split and the metric with a tiny synthetic frame. Do not download a dataset in the test.

## Done when

- The requested behavior works.
- `pytest` passes and the training entry point still runs the unchanged path, or you say why it cannot.
- The diff stays inside the task.
- You list anything you could not run.

Add it to the project

  1. 01

    Copy a starting file

    Copy the example Cursor testing rule on this page, or open the generator if you want different testing, strictness, or comment rules.

  2. 02

    Save it at .cursor/rules/testing.mdc

    Save it at `.cursor/rules/testing.mdc` in the Python ML repo, next to the always-on project rule. Leave `alwaysApply` false so it only joins test edits.

  3. 03

    Start a fresh agent session

    Rules files are read when a session starts. A chat that is already open may still be using the old instructions.

  4. 04

    Give it one small task

    Ask for one change a Python ML agent often gets wrong, such as a split that fits preprocessing on the training fold only. If it ignores the file, confirm the path and start a new session.

Questions about this file

Where do I put Cursor testing rule in a Python ML repo?

Save it at `.cursor/rules/testing.mdc` in the Python ML repo, next to the always-on project rule. Leave `alwaysApply` false so it only joins test edits.

Which tools read this Cursor testing rule?

Cursor loads `.cursor/rules/testing.mdc` when a file matches its globs. It does not replace `project.mdc`. Keep the always-on rule for stack conventions.

What does the Python ML example assume?

The example assumes Python for data or ML work. It does not assume PyTorch versus scikit-learn, or a particular experiment tracker. Use the libraries already in the environment.

Does VibeSpell upload my repository?

No. Recipe pages are static, and the generator builds the file in your browser from the options you pick. Your source code never leaves the machine.

Other files for Python ML

Cursor testing rule for other stacks