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.cursor/rules/testing.mdc

Cursor testing rule for Swift

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 Swift project. This repository is a Swift app for Apple platforms. Match SwiftUI or UIKit, whichever the target already uses. Stay off the main actor only for work that is actually background work.

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 a Swift iOS or multiplatform app. It does not assume SwiftData, a particular architecture acronym, or a third-party UI kit. Follow the UI stack already on screen.

Customize in the generatorBrowse the library

Example file

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

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

# Testing rules

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

## Stack

This repository is a Swift app for Apple platforms. Match SwiftUI or UIKit, whichever the target already uses. Stay off the main actor only for work that is actually background work.

## Commands

- Tests: `xcodebuild test`
- Open: `Open the project in Xcode and build the app target`

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

## Testing

Add or update tests when behavior changes.

Add an XCTest for the type that owns the rule. Do not snapshot the whole screen as the only check.

## Done when

- The requested behavior works.
- The app target builds and the XCTest for the type you changed passes.
- 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 Swift 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 Swift agent often gets wrong, such as a view model change that publishes on the main actor and has an XCTest. 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 Swift repo?

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

The example assumes a Swift iOS or multiplatform app. It does not assume SwiftData, a particular architecture acronym, or a third-party UI kit. Follow the UI stack already on screen.

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 Swift

Cursor testing rule for other stacks