What problem does it solve?
It solves the problem of hard-to-test Swift code that performs file I/O, network calls, or other external work, by replacing direct dependencies with small protocols and injectable implementations.
Core Features & Use Cases
- Protocol-based dependency injection: Abstract external concerns behind focused
Sendable protocols so your production code can run without real I/O during tests.
- Deterministic mocks for Swift Testing: Provide mock implementations (e.g., in-memory file systems, configurable read/write errors) to validate success and failure paths reliably.
- Concurrency-friendly architecture: Support actor-based designs by ensuring protocol contracts are compatible with Swift concurrency patterns.
Use case example: You’re building a Swift data sync component that reads data.json from a container URL and you need to test missing-container and corrupt-data error paths without touching the real file system.
Quick Start
Use the swift-protocol-di-testing skill to refactor your Swift external dependencies into small protocols, inject default production implementations in code, and inject mock protocol implementations in Swift Testing to validate behavior without performing real I/O.
