Pytest Application Layer Testing Purpose The application layer orchestrates domain logic with external dependencies. Tests verify that use cases correctly coordinate business logic and integration boundaries. When to Use This Skill Use when testing use cases and application services with "test use case", "mock gateways", "test orchestration", or "test DTOs". Do NOT use for domain testing (use ), adapter testing (use ), or pytest configuration (use ). Quick Start Test use cases with mocked gateways: Instructions Step 1: Structure Use Case Tests with Mocked Dependencies Step 2: Test Error Handl…