From axiom
Guides writing any test, debugging flaky tests, boosting test speed, and choosing Swift Testing vs XCTest. Covers unit, async, UI, and fast non-simulator tests.
How this skill is triggered — by the user, by Claude, or both
Slash command
/axiom:axiom-testingThe summary Claude sees in its skill listing — used to decide when to auto-load this skill
**You MUST use this skill for ANY testing-related question, including writing tests, debugging test failures, making tests faster, or choosing between testing approaches.**
You MUST use this skill for ANY testing-related question, including writing tests, debugging test failures, making tests faster, or choosing between testing approaches.
| 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 |
| 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 |
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)"];
}
skills/swift-testing.mdskills/testing-async.mdskills/ui-testing.mdskills/xctest-automation.mdskills/ui-recording.md/axiom:audit testingskills/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.| 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 |
Swift Testing (skills/swift-testing.md):
Async Testing (skills/testing-async.md):
UI Testing (skills/ui-testing.md):
XCUITest Automation (skills/xctest-automation.md):
UI Recording (skills/ui-recording.md):
Test quality audit → Launch testing-auditor agent or /axiom:audit testing (maps test coverage shape against production code, detects flaky patterns and speed issues, identifies untested critical paths, scores overall test health)
Flaky test analysis → Launch test-failure-analyzer agent (scans for patterns causing intermittent failures in Swift Testing: missing confirmation, shared mutable state, missing @MainActor)
| Thought | Reality |
|---|---|
| "Simple test question, I don't need the skill" | Proper patterns prevent test debt. skills/swift-testing.md has copy-paste solutions. |
| "I know XCTest well enough" | Swift Testing is significantly better for unit tests. Migration guide included. |
| "Tests are slow but it's fine" | Fast tests enable TDD. skills/swift-testing.md shows how to run without simulator. |
| "I'll fix the flaky test with a sleep()" | sleep() makes tests slower AND flakier. skills/ui-testing.md has condition-based waiting. |
| "I'll add tests later" | Tests written after implementation miss edge cases. |
| "I'll test the AI feature by asserting the model returns the right string" | A model isn't a pure function — that test fails on a synonym and passes on a fluent lie. Score a dataset and gate on an aggregate metric: axiom-ai (skills/foundation-models-evaluations.md). |
| "The AI output looked good when I tried it, so it's tested" | Trying a few prompts by hand measures nothing and catches no regression. That's the exact gap the Evaluations framework exists to close. |
User: "How do I write a unit test in Swift?"
→ Read: skills/swift-testing.md
User: "My UI tests are flaky in CI"
→ Check codebase: XCUIApplication/XCUIElement? → skills/ui-testing.md
→ Check codebase: @Test/#expect? → test-failure-analyzer (Agent)
User: "How do I test async code without flakiness?"
→ Read: skills/testing-async.md
User: "What's the Swift Testing equivalent of XCTestExpectation?"
→ Read: skills/testing-async.md
User: "I want my tests to run faster"
→ Read: skills/swift-testing.md (Strategy 1: Package extraction)
User: "Should I use Swift Testing or XCTest?"
→ Read: skills/swift-testing.md (Migration section) + this decision tree
User: "How do I record UI automation in Xcode 26?"
→ Read: skills/ui-recording.md
User: "Run my tests and show me what failed" → Invoke: test-runner (Agent)
User: "Audit my tests for quality issues" → Invoke: testing-auditor (Agent)
npx claudepluginhub charleswiltgen/axiom --plugin axiomGuides Swift Testing: test structure, #expect/#require macros, traits/tags, parameterized tests, plans, parallel execution, async patterns, XCTest migration. For new tests, modernizing suites, flaky debugging.
Guides Swift Testing code writing, review, and migration with patterns for structs over classes, async confirmations, parameterized tests, exit tests, attachments, and common pitfalls.
Writes, reviews, and improves Swift Testing code using modern APIs and best practices, including migration from XCTest.