Dep

Dep is a micro framework that implements a dependency injection using the Service Locator pattern and provides a convenient way to use these dependencies using @Dependency property wrapper

// Define a container and register your dependencies 
let container = Container()
       .register(AnyDecoder.self) { _ in JSONDecoder() }
       .register(AnyEncoder.self) { _ in JSONEncoder() }

// Resolve dependency using the previously defined container 
let dependency = container.resolve(AnyDecoder.self)

It is possible to register a dependency that expect its dependencies injected onto it in some way. For this purpose use the factory closure parameter

let container = Container()
       .register(AnyDecoder.self) { _ in JSONDecoder() }
       .register(AnyEncoder.self) { _ in JSONEncoder() }
       .register(ComplexObject.self) { resolver in 
          let decoder = resolver.resolve(AnyDecoder.self)
          let encoder = resolver.resolve(AnyEncoder.self)
          return ComplexObject(decoder: decoder, encoder: encoder)
       }

// Resolve dependency using the previously defined container 
let dependency = container.resolve(ComplexObject.self)

let defaultContainer = Container()
       .register(AnyDecoder.self) { _ in JSONDecoder() }
       .register(AnyEncoder.self) { _ in JSONEncoder() }


class ComplexObject {
  @Dependency(container: defaultContainer) var decoder: AnyDecoder 
  @Dependency(container: defaultContainer) var encoder: AnyEncoder
}

To test the classes that use @Dependency property wrapper it is possible to overwrite the container used to define a dependency

let testContainer = Container()
    .register(AnyDecoder.self) { _ in JSONDecoder() }
    .register(AnyEncoder.self) { _ in JSONEncoder() }
    .register(ComplexObject.self) { resolver in
        var result = ComplexObject()
        result.$decoder.container = resolver // overwrites decoder container
        result.$encoder.container = resolver
        return result
    }

class ComplexObjectsTests: XCTestCase {
  @Dependency(container: testContainer) var complexObject: ComplexObject

  func testThatItWorks() {
    XCTAssertTrue(complexObject.doesSomething())
  }
}

The Swift Package Manager is a tool for automating the distribution of Swift code and is integrated into the swift compiler.

Once you have your Swift package set up, adding Dep as a dependency is as easy as adding it to the dependencies value of your Package.swift or since XCode 11 you can do the same through XCode UI

dependencies: [
    .package(url: "https://github.com/kshin/Dep.git", from: "1.0.2")
]

• Xcode 11
• Swift 5.1

The MIT License (MIT)

Copyright (c) 2019 Ivan Lisovyi

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.