DependencyContainer

Adds support for @propertyWrapper dependency injection:

@Dependency(\.loginService) var loginService

In order to achieve this you just have to add your own key to DependencyContainer:

public protocol LoginService: AnyObject {
    func login(_ request: LoginRequest) async throws -> LoginResponse
}

public struct LoginServiceDependencyKey: LazyDependencyKey {
    public static var value: LoginService?
}

extension DependencyContainer {
    public var loginService: LoginService {
        get { DependencyContainer[LoginServiceDependencyKey.self] }
        set { DependencyContainer[LoginServiceDependencyKey.self] = newValue }
    }
}

Then on app launch you just need to override the dependency like so:

func registerDependencies() {
    DependencyContainer[LoginServiceDependencyKey.self] = LoginApiService()
}

Pros:

• Enables more modular architecture where dependencies don't need to be known by sibling modules
• No need to pass dependencies between files that don't use them

Cons:

• Can lead to run-time crashes when dependencies are not provided at launch, this can be mitigated using unit tests

Inspired by: Antoine van der Lee and Point Free