Axiom Testing

Covers the entire testing landscape for Swift and Xcode, from unit tests with Swift Testing to UI automation with XCUITest. The quick reference table is genuinely useful for jumping to the right pattern when tests are flaky or slow. Notable for its opinionated stance on Swift Testing over XCTest for unit tests, complete with migration guidance and the "fast tests without simulator" architecture. The anti-rationalization section calling out sleep() in tests is spot on. Includes decision trees for routing to the right sub-skill and references to companion agents for automated test analysis. If you write tests in Swift, this consolidates patterns that would otherwise live in scattered Xcode documentation and Stack Overflow threads.

skills.sh installs: 1.4K
GitHub stars: 1.3K
last updated: Aug 21, 2026

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Install

$ npx -y skills add charleswiltgen/axiom --skill axiom-testing --agent claude-code

Installs into .claude/skills of the current project.

Files

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.

Bundled tools on Claude Code: if command -v <tool> finds nothing (hooks off or --bare), use <plugin-root>/tools/<tool> in place of the bare name; <plugin-root> is two levels above this skill's Base directory for this skill: path.

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.