/axiom-testing

name: axiom-testing
description: Use when writing ANY test, debugging flaky tests, making tests faster, or choosing Swift Testing vs XCTest. Covers unit tests, UI tests, async testing, test architecture.
license: MIT

Testing

**You MUST use this skill for ANY testing-related question, including writing tests, debugging test failures, making tests faster, or choosing between testing approaches.**

<!-- AXIOM_AUDITOR_INLINE_BEGIN — rewritten for Codex by scripts/build-codex.ts; do not hand-edit --> > **Auditors are skills here.** Where this router says "Launch `some-auditor` agent", invoke the > matching Codex skill instead — same procedure, no Claude Code agent required. > > Available: `axiom-analyze-test-failures`, `axiom-audit-testing`. > > The ones that shell out — builds, tests, simulators, crash symbolication — need shell access to run. <!-- AXIOM_AUDITOR_INLINE_END -->

Quick Reference

| Symptom / Task | Reference | |----------------|-----------| | Writing unit tests, Swift Testing (@Test, #expect) | See `skills/swift-testing.md` | | Making tests run without simulator | See `skills/swift-testing.md` | | Parameterized tests, tags, traits | See `skills/swift-testing.md` | | Migrating from XCTest to Swift Testing | See `skills/swift-testing.md` | | Warning-severity issues / cancelling a test — `Issue.record(severity:)`, `Test.cancel` (`OS27`) | See `skills/swift-testing.md` | | Testing async/await functions | See `skills/testing-async.md` | | confirmation for callbacks | See `skills/testing-async.md` | | @MainActor tests, parallel execution | See `skills/testing-async.md` | | Writing UI tests, XCUITest | See `skills/ui-testing.md` | | Condition-based waiting patterns | See `skills/ui-testing.md` | | Recording UI Automation (Xcode 26) | See `skills/ui-testing.md` | | Network conditioning, multi-factor testing | See `skills/ui-testing.md` | | Testing resizable apps: dimension matrix, RTL/pseudoloc launch args, live-resize passes | See `skills/ui-testing.md` | | Test Face ID/Touch ID, orientation, or simulator state from CI — devicectl | See `skills/ui-testing.md` | | XCUIElement queries, waiting strategies | See `skills/xctest-automation.md` | | Accessibility identifiers, test plans | See `skills/xctest-automation.md` | | CI/CD test execution | See `skills/xctest-automation.md` | | Record/Replay/Review workflow (Xcode 26) | See `skills/ui-recording.md` | | Test plan multi-configuration replay | See `skills/ui-recording.md` | | Enhancing recorded tests for stability | See `skills/ui-recording.md` | | Testing a generative AI feature — output isn't deterministic, so `#expect(result == expected)` doesn't hold (`OS27`) | See axiom-ai (`skills/foundation-models-evaluations.md`) for the discipline, then axiom-ai (`skills/foundation-models-evaluations-ref.md`) for the API |

Decision Tree

digraph testing {
    start [label="Testing task" shape=ellipse];
    what [label="What kind of test?" shape=diamond];

    start -> what;
    what -> "skills/swift-testing.md" [label="unit tests,\nSwift Testing,\nfast tests"];
    what -> "skills/testing-async.md" [label="testing async code,\ncallbacks,\nconfirmation"];
    what -> "skills/ui-testing.md" [label="UI tests,\nflaky tests,\nrecording"];
    what -> "skills/xctest-automation.md" [label="XCUITest patterns,\nelement queries"];
    what -> "skills/ui-recording.md" [label="Xcode 26\nRecord/Replay/Review"];
    what -> "axiom-ai (skills/foundation-models-evaluations.md)" [label="generative AI feature\n(nondeterministic output)"];
}

1. Writing unit tests / Swift Testing? → `skills/swift-testing.md` 2. Testing async/await code? → `skills/testing-async.md` 3. Writing UI tests / XCUITest / flaky tests? → `skills/ui-testing.md` 4. XCUIElement queries, waiting, test plans, CI? → `skills/xctest-automation.md` 5. Record UI interactions (Xcode 26)? → `skills/ui-recording.md` 6. Flaky tests / race conditions (Swift Testing)? → test-failure-analyzer (Agent) 7. Tests crash / environment wrong? → See axiom-build (skills/xcode-debugging.md) 8. Run tests from CLI / parse results? → test-runner (Agent) 9. Fix failing tests automatically? → test-debugger (Agent) 10. Want test quality audit? → testing-auditor (Agent) or `axiom-audit-testing` 11. Automate without XCUITest / AXe CLI? → simulator-tester (Agent) + See axiom-xcode-mcp (skills/axe-ref.md) 12. Testing a Foundation Models / generative feature? → See axiom-ai (`skills/foundation-models-evaluations.md`) for the discipline (dataset design, guardrails vs optimization target, judge calibration), then axiom-ai (`skills/foundation-models-evaluations-ref.md`) for the API. The Evaluations framework (`OS27`) runs *inside* Swift Testing via the `.evaluates` trait — it doesn't replace it. A model isn't a pure function, so you score outputs against a dataset and gate on an aggregate metric instead of asserting on one exact string.

Swift Testing vs XCTest Quick Guide

| Need | Use | |------|-----| | Unit tests (logic, models) | Swift Testing | | UI tests (tap, swipe, assert screens) | XCUITest (XCTest) | | Tests without simulator | Swift Testing + Package/Framework | | Parameterized tests | Swift Testing | | Performance measurements | XCTest (XCTMetric) | | Objective-C tests | XCTest |

Critical Patterns

**Swift Testing** (`skills/swift-testing.md`):

• @Test/@Suite macros, #expect/#require assertions
• Parameterized testing for eliminating repetitive tests
• Fast tests architecture: Package extraction, Host Application: None
• Reliable async testing with withMainSerialExecutor and TestClock
• Migration guide from XCTest (comparison table)
• XCTestCase + Swift 6.2 MainActor compatibility fix

**Async Testing** (`skills/testing-async.md`):

• confirmation for single/multiple callbacks
• expectedCount: 0 to verify something never happens
• @MainActor test isolation
• Timeout control with .timeLimit
• Parallel execution gotchas and .serialized

**UI Testing** (`skills/ui-testing.md`):

• Condi