swift-protocol-di-testing

Abstract external dependencies behind small protocols for testable Swift code.

Updated Apr 2, 2026
One-click install
npx skills add https://github.com/richardnpaul/everything-vscode-copilot --skill swift-protocol-di-testing-richardnpaul
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: swift-protocol-di-testing
Source: https://github.com/richardnpaul/everything-vscode-copilot/tree/main/.github/skills/swift-protocol-di-testing
Command: npx skills add https://github.com/richardnpaul/everything-vscode-copilot --skill swift-protocol-di-testing-richardnpaul

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

Patterns for making Swift code testable by abstracting external dependencies (file system, network, iCloud) behind small, focused protocols. Enables deterministic tests without I/O.

Core Features & Use Cases

  • Define Small, Focused Protocols: Each protocol handles exactly one external concern.
  • Create Default (Production) Implementations
  • Create Mock Implementations for Testing
  • Inject Dependencies with Default Parameters
  • Write Tests with Swift Testing

Quick Start

Create a testable Swift module by introducing protocols and mock implementations for external dependencies.

Frequently Asked Questions about swift-protocol-di-testing

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I make Swift code testable with dependency injection?▼

Use dependency injection in Swift by abstracting external dependencies behind small, focused protocols, providing default implementations for production and mock implementations for testing. This enables deterministic tests without I/O across app and test contexts.

What is the best way to write deterministic Swift tests without network or file I/O?▼

Abstract external dependencies behind small protocols and inject mock implementations to write deterministic Swift tests. This removes network and file I/O from test contexts, ensuring reliable execution without external API dependencies.

How do I mock network requests in Swift Testing?▼

Define a small protocol for the network concern and create a mock implementation to mock network requests in Swift Testing. Inject this mock into your tests to verify API interactions deterministically without real I/O.

Does dependency injection with protocols work in SwiftUI previews?▼

Yes, dependency injection with protocols works in SwiftUI previews. Inject mock implementations conforming to your focused protocols into preview contexts to render views deterministically without external dependencies.

Do I need Sendable conformance for Swift protocol mocking across actors?▼

Yes, Sendable conformance is required for Swift protocol mocking across actors. This ensures safe concurrency when passing dependency implementations between actors in app, test, and SwiftUI preview contexts.