Testing

Testing — Foundations Skill

Purpose

Route Apple-platform testing implementation tasks to the minimum required Knowledge Contracts. v1 scope is a curated subset of XCTest (case structure, assertions, skipping), the newer Swift Testing framework (@Test/#expect/#require/@Suite/Tag), parameterized and async/throws test functions in both frameworks, XCUITest (XCUIApplication/XCUIElement), and XCTestExpectation for callback-based asynchronous code -- not performance testing, Test Plans, snapshot testing, UI test recording, mocking/DI patterns, or accessibility audits.

Routing

Load only the contracts relevant to the task. All paths relative to knowledge/testing/.

• Subclassing XCTestCase; naming a test-prefixed method; overriding setUp()/setUpWithError()/tearDown()/tearDownWithError(); using XCTAssertEqual/XCTAssertTrue/XCTAssertNil/XCTAssertThrowsError/ XCTFail; or skipping with XCTSkip/XCTSkipIf/XCTSkipUnless -> xctest-case-structure-and-assertions.md
• Writing import Testing; declaring @Test; choosing between #expect(_:) and #require(_:); grouping with @Suite; or tagging with Tag/.tags(_:) -> swift-testing-fundamentals.md
• Parameterizing a @Test with arguments: over one collection, two collections, or zip(...); or writing an async/async throws test function in either framework -> parameterized-and-async-tests.md
• Launching the app under test with XCUIApplication()/.launch(); setting continueAfterFailure; querying XCUIElements by accessibilityIdentifier; or asserting with .exists/ .waitForExistence(timeout:) -> ui-testing-with-xcuiapplication.md
• Testing a delegate callback or completion-handler API with no async/await entry point via XCTestExpectation, expectation(description:), .fulfill(), or await fulfillment(of:timeout:) -> expectations-for-asynchronous-code.md

Never load more than the contracts relevant to the specific question.

Stop Conditions

Stop and report if the requested topic has no matching Knowledge Contract in knowledge/testing/ -- do not guess or fall back to general knowledge. Performance testing (measure { }, XCTMetric, XCTClockMetric) is out of scope entirely -- do not fabricate performance-testing guidance. Xcode Test Plans (.xctestplan) and code coverage configuration are owned by the xcode domain -- report the boundary rather than answer from this skill. Snapshot testing (e.g. swift-snapshot-testing) is a third-party pattern, not an Apple-documented API -- out of scope entirely. Xcode's UI test recording is an IDE workflow, not an API surface -- out of scope entirely. Mocking, dependency injection, and test-double patterns are general software-engineering technique, not Apple-API-specific -- out of scope entirely. XCUIApplication().performAccessibilityAudit() is owned by the accessibility domain -- report the boundary rather than build it here.