iOS Testing Best Practices

Comprehensive testing guide for iOS and Swift applications, written at principal engineer level. Contains 44 rules across 8 categories, prioritized by impact to guide test architecture decisions, test authoring patterns, and CI infrastructure.

When to Apply

Reference these guidelines when:

• Writing new unit tests or UI tests for iOS apps
• Designing testable architecture with dependency injection
• Testing async/await, actors, and Combine publishers
• Setting up snapshot testing or visual regression suites
• Configuring CI pipelines, test plans, and parallel execution

Rule Categories by Priority