test-failure-analyzer

Diagnoses WHY tests fail, especially intermittent/flaky failures in Swift Testing with focus on async patterns, race conditions, and CI-specific issues.

How to Use This Agent

Natural language (automatic triggering):

• "My tests fail randomly in CI"
• "This test passes locally but fails in CI"
• "I have a flaky test that fails 20% of the time"
• "My Swift Testing tests have race conditions"
• "Test passes individually, fails when run with others"

Explicit command:

/axiom:audit test-failures

What It Does

Critical (Will Cause Intermittent Failures)

• Missing await confirmation – Async callback without proper waiting
• Missing @MainActor – Tests that call main-actor UI types without @MainActor (a build failure in every Swift mode, not a flake)

High Priority (Parallel Execution Failures)

• Shared mutable state – static var in test suites causing race conditions
• Order-dependent tests – Tests that only pass in specific order

Medium Priority (Timing Issues)

• Task.sleep in assertions – Arbitrary waits that fail in CI
• Missing .serialized trait – Tests with shared resources run in parallel

Low Priority (Edge Cases)

• Date comparisons – Timezone/DST-dependent assertions

Example Output

# Test Failure Analysis Results

## Summary
- **CRITICAL Issues**: 2
- **HIGH Issues**: 1
- **Flakiness Risk Score**: HIGH

### CRITICAL: Missing `await confirmation`
- `Tests/NetworkTests.swift:45`
  ```swift
  @Test func fetchUser() async {
      var user: User?
      api.fetchUser { user = $0 }
      #expect(user != nil)  // FLAKY!
  }
  ```
  - **Root cause**: Test completes before async callback
  - **Fix**: Wrap in `await confirmation { ... }`

### HIGH: Shared Mutable State
- `Tests/CacheTests.swift:12` – `static var testCache`
  - **Root cause**: Parallel tests mutate same collection
  - **Fix**: Use instance property instead

Verification

After fixes, verify stability:

# Run tests multiple times
swift test --parallel --num-workers 8

# Run specific test repeatedly
swift test --filter "TestName" --iterations 100

Related

• testing-auditor – Broader test quality audit
• swift-testing – Swift Testing patterns and best practices
• testing-async – Async testing patterns