Vaccine

Simple dependency injection library using Swift property wrappers

Tired of creating a lot of property on initializers of your classes so it's easier to test them? With Vaccine is possible to define properties in your classes using @propertyWrappers in a very simple way!

Installation

Swift Package Manager

In Xcode go to File->Swift Packages->Add Package Dependency... and paste the url:

https://github.com/munirwanis/Vaccine.git

If you are adding this package as a dependency to another package, paste this on your Package.swift file:

dependencies: [
    .package(url: "https://github.com/munirwanis/Vaccine.git", .upToNextMajor(from: "1.0.0" )),
]

Manual

Since this project has no dependencies, it's possible to drag the source files to your project.

Other package managers

If manual or SPM are not a option, pull requests will be very welcome to help support other platforms.

Compatibility

• Swift 5.1+
• Xcode 11+

Usage

Register dependencies

You can use the starting point of your application to register the dependencies that will be resolved later. Let's say we have a protocol for a service called SomeServiceProtol, and I want to resolve it with my class SomeService.

import Foundation
import Vaccine

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
    
    
    func application(_ application: UIApplication,
                     configurationForConnecting connectingSceneSession: UISceneSession,
                     options: UIScene.ConnectionOptions) -> UISceneConfiguration {
        
        // Registers the dependency for my service
        Vaccine.setCure(for: SomeServiceProtocol.self, with: SomeService())

        return UISceneConfiguration(name: "Default Configuration", sessionRole: connectingSceneSession.role)
    }
}

You can also set the property isUnique to true to ensure that the object injected is singleton.

Vaccine.setCure(for: SomeServiceProtocol.self, isUnique: true, with: SomeService())

If your object needs to do some complex things you can also pass the resolver as a closure, like this:

// Can also use `isUnique` property
Vaccine.setCure(for: SomeServiceProtocol.self) {
    let item = ["Hello", "World"].randomElement() ?? ""
    return SomeService(text: item)
}

Resolve dependencies

To resolve dependencies is pretty simple, simply use @Inject property wrapper inside your class:

class SomeViewModel {
    // Will instantiate or get an already instantiated (if singleton) version of  `SomeService`
    @Inject(SomeServiceProtocol.self) var service
    
    func getText() -> String {
        service.getText()
    }
}

Contributions

Found a bug or have a improvement suggestion? Open a issue or help by submitting a Pull Request! 😊