Skip to content
vibespell

.cursor/rules/testing.mdc

Cursor testing rule for .NET

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 .NET project. This repository is a .NET application. Nullable reference types stay enabled. Match minimal APIs or controllers, whichever the project already uses, and ship schema changes as migrations.

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 modern .NET with nullable enabled. It does not assume MVC versus minimal APIs, or EF Core versus another store. Follow the host that is already in Program.cs.

Customize in the generatorBrowse the library

Example file

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

---
description: "Testing rules for a .NET repository"
globs: "**/*Tests.cs"
alwaysApply: false
---

# Testing rules

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

## Stack

This repository is a .NET application. Nullable reference types stay enabled. Match minimal APIs or controllers, whichever the project already uses, and ship schema changes as migrations.

## Commands

- Test: `dotnet test`
- Run: `dotnet run`
- Format: `dotnet format`

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

## Testing

Add or update tests when behavior changes.

Add an xUnit, NUnit, or MSTest test matching the repo. Cover the validation failure.

## Done when

- The requested behavior works.
- `dotnet test` passes and `dotnet format` leaves the diff clean.
- 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 .NET 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 .NET agent often gets wrong, such as an endpoint that returns a validation problem for a bad body instead of throwing. 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 .NET repo?

Save it at `.cursor/rules/testing.mdc` in the .NET 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 .NET example assume?

The example assumes modern .NET with nullable enabled. It does not assume MVC versus minimal APIs, or EF Core versus another store. Follow the host that is already in Program.cs.

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 .NET

Cursor testing rule for other stacks