---
description: "Swift testing extending common rules"
globs: ["**/*.swift", "**/Package.swift"]
alwaysApply: false
---
# Swift Testing

> This file extends the common testing rule with Swift specific content.

## Framework

Use **Swift Testing** (`import Testing`) for new tests. Use `@Test` and `#expect`:

```swift
@Test("User creation validates email")
func userCreationValidatesEmail() throws {
    #expect(throws: ValidationError.invalidEmail) {
        try User(email: "not-an-email")
    }
}
```

## Test Isolation

Each test gets a fresh instance -- set up in `init`, tear down in `deinit`. No shared mutable state between tests.

## Parameterized Tests

```swift
@Test("Validates formats", arguments: ["json", "xml", "csv"])
func validatesFormat(format: String) throws {
    let parser = try Parser(format: format)
    #expect(parser.isValid)
}
```

## Coverage

```bash
swift test --enable-code-coverage
```

## Reference

See skill: `swift-protocol-di-testing` for protocol-based dependency injection and mock patterns with Swift Testing.