[Feature] Dependencies (#3)

This PR contains the work done to provide a simple dependency injection feature whenever required.

To provide further details about this work:
- [x] renamed the `Coordinator` target in the `Package` file as `Coordination`;
- [x] declared the `Dependencies` target in the `Package` file;
- [x] defined the `DependencyKey` public protocol;
- [x] implemented the `DependencyService` public service;
- [x] implemented the `Dependency` public property wrapper;

Co-authored-by: Javier Cicchelli <javier@rock-n-code.com>
Reviewed-on: #3

Tests/Coordination/Platform/iOS/Helpers/TestCoordinators.swift

@@ -1,12 +1,12 @@
 //
 //  TestCoordinators.swift
-//  CoordinatorTests
+//  CoordinationTests
 //
 //  Created by Javier Cicchelli on 11/04/2023.
 //  Copyright © 2023 Röck+Cöde. All rights reserved.
 //
 
-import Coordinator
+import Coordination
 import UIKit
 
 // MARK: - Test coordinators

Tests/Coordination/Platform/iOS/Protocols/CoordinatorTests.swift

@@ -1,12 +1,12 @@
 //
 //  CoordinatorTests.swift
-//  CoordinatorTests
+//  CoordinationTests
 //
 //  Created by Javier Cicchelli on 11/04/2023.
 //  Copyright © 2023 Röck+Cöde. All rights reserved.
 //
 
-import Coordinator
+import Coordination
 import UIKit
 import XCTest
 

Tests/Dependencies/Helpers/TestServices.swift

@@ -0,0 +1,34 @@
+//
+//  TestServices.swift
+//  DependenciesTests
+//
+//  Created by Javier Cicchelli on 11/04/2023.
+//  Copyright © 2023 Röck+Cöde. All rights reserved.
+//
+
+import Dependencies
+
+// MARK: - Protocols
+
+protocol TestService {}
+
+// MARK: - Services
+
+struct SomeService: TestService, Equatable {}
+struct SomeOtherService: TestService, Equatable {}
+
+// MARK: - DependencyKey
+
+struct TestServiceKey: DependencyKey {
+    static var currentValue: TestService = SomeService()
+}
+
+// MARK: - DependencyService+Keys
+
+extension DependencyService {
+    var testService: TestService {
+        get { Self[TestServiceKey.self] }
+        set { Self[TestServiceKey.self] = newValue }
+    }
+}
+

Tests/Dependencies/Property Wrappers/DependencyTests.swift

@@ -0,0 +1,73 @@
+//
+//  DependencyTests.swift
+//  DependenciesTests
+//
+//  Created by Javier Cicchelli on 11/04/2023.
+//  Copyright © 2023 Röck+Cöde. All rights reserved.
+//
+
+import Dependencies
+import XCTest
+
+final class DependencyTests: XCTestCase {
+    
+    // MARK: Properties
+    
+    private var subject: TestSubject!
+    
+    // MARK: Setup
+    
+    override func setUp() {
+        DependencyService[\.testService] = SomeService()
+    }
+    
+    // MARK: Tests
+
+    func test_readTestService() {
+        // GIVEN
+        subject = .init()
+        
+        // WHEN
+        let service = subject.testService
+        
+        // THEN
+        XCTAssertNotNil(service)
+        XCTAssert(service is SomeService)
+    }
+    
+    func test_writeDependencyKey() async throws {
+        // GIVEN
+        subject = .init()
+        
+        subject.testService = SomeOtherService()
+        
+        // WHEN
+        let service = DependencyService[\.testService]
+        
+        // THEN
+        XCTAssertNotNil(service)
+        XCTAssert(service is SomeOtherService)
+    }
+    
+    func test_writeDependencyKeyTwice() async throws {
+        // GIVEN
+        subject = .init()
+        
+        subject.testService = SomeOtherService()
+        subject.testService = SomeService()
+        
+        // WHEN
+        let service = DependencyService[\.testService]
+        
+        // THEN
+        XCTAssertNotNil(service)
+        XCTAssert(service is SomeService)
+    }
+
+}
+
+// MARK: - TestSubject
+
+private struct TestSubject {
+    @Dependency(\.testService) var testService
+}

Tests/Dependencies/Services/DependencyServiceTests.swift

@@ -0,0 +1,57 @@
+//
+//  DependencyServiceTests.swift
+//  DependenciesTests
+//
+//  Created by Javier Cicchelli on 11/04/2023.
+//  Copyright © 2023 Röck+Cöde. All rights reserved.
+//
+
+import Dependencies
+import XCTest
+
+final class DependencyServiceTests: XCTestCase {
+
+    // MARK: Setup
+    
+    override func setUp() {
+        DependencyService[\.testService] = SomeService()
+    }
+    
+    // MARK: Tests
+
+    func test_readDependencyKey() async throws {
+        // GIVEN
+        // WHEN
+        let service = DependencyService[\.testService]
+        
+        // THEN
+        XCTAssertNotNil(service)
+        XCTAssert(service is SomeService)
+    }
+    
+    func test_writeDependencyKey() async throws {
+        // GIVEN
+        DependencyService[\.testService] = SomeOtherService()
+        
+        // WHEN
+        let service = DependencyService[\.testService]
+        
+        // THEN
+        XCTAssertNotNil(service)
+        XCTAssert(service is SomeOtherService)
+    }
+    
+    func test_writeDependencyKeyTwice() async throws {
+        // GIVEN
+        DependencyService[\.testService] = SomeOtherService()
+        DependencyService[\.testService] = SomeService()
+        
+        // WHEN
+        let service = DependencyService[\.testService]
+        
+        // THEN
+        XCTAssertNotNil(service)
+        XCTAssert(service is SomeService)
+    }
+
+}