claude-code/claude/rules/swift/testing.md

paths
**/*.swift **/Package.swift

Swift Testing

This file extends common/testing.md with Swift specific content.

Framework

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

@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

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

Coverage

swift test --enable-code-coverage

Reference

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