Merge pull request #5 from rock-n-code/feature/dependency-service

Feature: Dependency service

Libraries/Package.swift

@@ -8,11 +8,16 @@ let package = Package(
     products: [
         .library(
             name: "Libraries",
-            targets: ["APIService"]),
+            targets: [
+                "APIService",
+                "DependencyService"
+            ]
+        ),
     ],
     dependencies: [],
     targets: [
         .target(name: "APIService"),
+        .target(name: "DependencyService"),
         .testTarget(
             name: "APIServiceTests",
             dependencies: ["APIService"]

Libraries/Sources/DependencyService/Property Wrappers/Dependency.swift

@@ -0,0 +1,29 @@
+//
+//  Dependency.swift
+//  DependencyService
+//
+//  Created by Javier Cicchelli on 05/12/2022.
+//  Copyright © 2022 Röck+Cöde. All rights reserved.
+//
+
+@propertyWrapper
+public struct Dependency<D> {
+    
+    // MARK: Properties
+    
+    private let keyPath: WritableKeyPath<DependencyStore, D>
+    
+    // MARK: Computed
+    
+    public var wrappedValue: D {
+        get { DependencyStore[keyPath] }
+        set { DependencyStore[keyPath] = newValue }
+    }
+    
+    // MARK: Initialisers
+    
+    public init(_ keyPath: WritableKeyPath<DependencyStore, D>) {
+        self.keyPath = keyPath
+    }
+
+}

Libraries/Sources/DependencyService/Protocols/DependencyKey.swift

@@ -0,0 +1,19 @@
+//
+//  DependencyKey.swift
+//  DependencyService
+//
+//  Created by Javier Cicchelli on 05/12/2022.
+//  Copyright © 2022 Röck+Cöde. All rights reserved.
+//
+
+public protocol DependencyKey {
+
+    // MARK: Associated types
+
+    associatedtype Value
+    
+    // MARK: Properties
+    
+    static var currentValue: Value { get set }
+    
+}

Libraries/Sources/DependencyService/Structs/DependencyStore.swift

@@ -0,0 +1,27 @@
+//
+//  DependencyStore.swift
+//  DependencyService
+//
+//  Created by Javier Cicchelli on 05/12/2022.
+//  Copyright © 2022 Röck+Cöde. All rights reserved.
+//
+
+public struct DependencyStore {
+    
+    // MARK: Properties
+
+    private static var current = Self()
+    
+    // MARK: Functions
+    
+    public static subscript<K>(key: K.Type) -> K.Value where K: DependencyKey {
+        get { key.currentValue }
+        set { key.currentValue = newValue }
+    }
+    
+    public static subscript<D>(_ keyPath: WritableKeyPath<DependencyStore, D>) -> D {
+        get { current[keyPath: keyPath] }
+        set { current[keyPath: keyPath] = newValue }
+    }
+
+}