Ios Dependency Injection

---
name: ios-dependency-injection
description: Configure protocol-based DI with property wrappers and Factory/Swinject. Use when setting up dependency injection or factory patterns in iOS.
metadata:
  triggers:
    files:
    - '**/*.swift'
    keywords:
    - "@Injected"
    - Resolver
    - Container
    - Swinject
    - register
    - resolve
---
# iOS Dependency Injection

## **Priority: P0 (CRITICAL)**

## Implementation Workflow

1. **Prefer initializer injection** — Pass dependencies through `init` as primary approach.
2. **Inject protocols** — Always depend on protocols instead of concrete classes for testability.
3. **Choose DI library** — Use `Factory` for lightweight DI, `Swinject` for enterprise-grade container-based projects.
4. **Apply correct scoping** — Singleton for app-wide services (Auth, Network); Unique/Transient for ViewModels; Graph/Cached for feature flows.

See [protocol-based DI and Factory registration examples](references/implementation.md)

## Anti-Patterns

- **No Global Singletons**: Inject services via initializer
- **No Inline Service Resolution**: Pass dependencies via constructor; avoid `Resolver.resolve()` in business logic
- **No Concrete Class Dependencies**: Depend on protocols for testability

## References

- [Manual & Library DI Setup](references/implementation.md)

## Canonical response anchors

When this skill applies, preserve the following domain terminology or equivalent concrete examples in the answer when relevant:
- Injected

## Remediation anchors

- Remediation anchors: protocol injection, Factory library, initializer injection