[Library] Coordination library (#15)

This PR contains the work done to implement the necessary protocols and router to implement the Coordinators pattern in the app.

Reviewed-on: rock-n-code/app-reviews#15
Co-authored-by: Javier Cicchelli <javier@rock-n-code.com>
Co-committed-by: Javier Cicchelli <javier@rock-n-code.com>

Libraries/Coordination/Test/Helpers/Coordinators/OtherCoordinator.swift

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+//
+//  OtherCoordinator.swift
+//  ReviewsCoordinationTest
+//
+//  Created by Javier Cicchelli on 21/03/2024.
+//  Copyright © 2024 Röck+Cöde. All rights reserved.
+//
+
+import ReviewsCoordinationKit
+
+final class OtherCoordinator: Coordinator {
+    
+    // MARK: Constants
+    let router: Router
+    
+    // MARK: Properties
+    var children: [Coordinator] = []
+
+    // MARK: Initialisers
+    init(router: Router) {
+        self.router = router
+    }
+    
+    // MARK: Functions
+    func present(
+        animated: Bool,
+        onDismiss: (() -> Void)?
+    ) {
+        router.present(
+            OtherViewController(),
+            animated: animated,
+            onDismiss: onDismiss
+        )
+    }
+    
+}

Libraries/Coordination/Test/Helpers/Coordinators/SomeCoordinator.swift

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+//
+//  SomeCoordinator.swift
+//  ReviewsCoordinationTest
+//
+//  Created by Javier Cicchelli on 21/03/2024.
+//  Copyright © 2024 Röck+Cöde. All rights reserved.
+//
+
+import ReviewsCoordinationKit
+
+final class SomeCoordinator: Coordinator {
+    
+    // MARK: Constants
+    let router: Router
+
+    // MARK: Properties
+    var children: [Coordinator] = []
+
+    // MARK: Initialisers
+    init(router: Router) {
+        self.router = router
+    }
+    
+    // MARK: Functions
+    func present(
+        animated: Bool,
+        onDismiss: (() -> Void)?
+    ) {
+        router.present(
+            SomeViewController(),
+            animated: animated,
+            onDismiss: onDismiss
+        )
+    }
+    
+}

Libraries/Coordination/Test/Helpers/Routers/SpyRouter.swift

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+//
+//  SpyRouter.swift
+//  ReviewsCoordinationTest
+//
+//  Created by Javier Cicchelli on 21/03/2024.
+//  Copyright © 2024 Röck+Cöde. All rights reserved.
+//
+
+import ReviewsCoordinationKit
+import UIKit
+
+final class SpyRouter: Router {
+    
+    // MARK: Properties
+    var animated: Bool?
+    var onDismiss: OnDismissClosure?
+    var state: State = .initialised
+    var viewController: UIViewController?
+
+    // MARK: Functions
+    func present(
+        _ viewController: UIViewController,
+        animated: Bool,
+        onDismiss: OnDismissClosure?
+    ) {
+        self.viewController = viewController
+        self.animated = animated
+        self.onDismiss = onDismiss
+        self.state = .presented
+    }
+    
+    func dismiss(animated: Bool) {
+        self.animated = animated
+        self.state = .dismissed
+    }
+    
+}
+
+// MARK: - Enumerations
+extension SpyRouter {
+    enum State {
+        case initialised
+        case presented
+        case dismissed
+    }
+}

Libraries/Coordination/Test/Helpers/TestViewControllers.swift

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+//
+//  TestViewControllers.swift
+//  ReviewsCoordinationTests
+//
+//  Created by Javier Cicchelli on 21/03/2024.
+//  Copyright © 2024 Röck+Cöde. All rights reserved.
+//
+
+import UIKit
+
+final class SomeViewController: UIViewController {}
+final class OtherViewController: UIViewController {}

Libraries/Coordination/Test/Tests/Protocols/CoordinatorTests.swift

@@ -0,0 +1,143 @@
+//
+//  CoordinatorTests.swift
+//  ReviewsCoordinationTest
+//
+//  Created by Javier Cicchelli on 21/03/2024.
+//  Copyright © 2024 Röck+Cöde. All rights reserved.
+//
+
+import ReviewsCoordinationKit
+import UIKit
+import XCTest
+
+final class CoordinatorTests: XCTestCase {
+    
+    // MARK: Properties
+    private var router: SpyRouter!
+    private var coordinator: Coordinator!
+    
+    // MARK: Tests
+    func testPresent_withoutOnDismissClosure() {
+        // Executing this test on the main thread is required as a `UIViewController` instance in being initialised here.
+        DispatchQueue.main.async {
+            // GIVEN
+            self.router = SpyRouter()
+            self.coordinator = SomeCoordinator(router: self.router)
+
+            // WHEN
+            self.coordinator.present(
+                animated: false,
+                onDismiss: nil
+            )
+            
+            // THEN
+            XCTAssertTrue(self.coordinator.children.isEmpty)
+            XCTAssertEqual(self.router.state, .presented)
+            XCTAssertTrue(self.router.viewController is SomeViewController)
+            XCTAssertFalse(self.router.animated ?? true)
+            XCTAssertNil(self.router.onDismiss)
+        }
+    }
+    
+    func testPresent_withOnDismissClosure() {
+        // Executing this test on the main thread is required as a `UIViewController` instance in being initialised here.
+        DispatchQueue.main.async {
+            // GIVEN
+            self.router = SpyRouter()
+            self.coordinator = OtherCoordinator(router: self.router)
+            
+            // WHEN
+            self.coordinator.present(animated: true) {}
+            
+            // THEN
+            XCTAssertTrue(self.coordinator.children.isEmpty)
+            XCTAssertEqual(self.router.state, .presented)
+            XCTAssertTrue(self.router.viewController is OtherViewController)
+            XCTAssertTrue(self.router.animated ?? false)
+            XCTAssertNotNil(self.router.onDismiss)
+        }
+    }
+    
+    func testPresentChild_withoutOnDismissClosure() {
+        // Executing this test on the main thread is required as a `UIViewController` instance in being initialised here.
+        DispatchQueue.main.async {
+            // GIVEN
+            self.router = SpyRouter()
+            self.coordinator = SomeCoordinator(router: self.router)
+            
+            let child = OtherCoordinator(router: self.router)
+            
+            // WHEN
+            self.coordinator.present(
+                child: child,
+                animated: false
+            )
+            
+            // THEN
+            XCTAssertFalse(self.coordinator.children.isEmpty)
+            XCTAssertEqual(self.coordinator.children.count, 1)
+            XCTAssertEqual(self.router.state, .presented)
+            XCTAssertTrue(self.router.viewController is OtherViewController)
+            XCTAssertFalse(self.router.animated ?? true)
+            XCTAssertNil(self.router.onDismiss)
+        }
+    }
+    
+    func testPresentChild_withOnDismissClosure() {
+        // Executing this test on the main thread is required as a `UIViewController` instance in being initialised here.
+        DispatchQueue.main.async {
+            // GIVEN
+            self.router = SpyRouter()
+            self.coordinator = OtherCoordinator(router: self.router)
+            
+            let child = SomeCoordinator(router: self.router)
+            
+            // WHEN
+            self.coordinator.present(
+                child: child,
+                animated: true
+            ) {}
+            
+            // THEN
+            XCTAssertFalse(self.coordinator.children.isEmpty)
+            XCTAssertEqual(self.coordinator.children.count, 1)
+            XCTAssertEqual(self.router.state, .presented)
+            XCTAssertTrue(self.router.viewController is SomeViewController)
+            XCTAssertTrue(self.router.animated ?? false)
+            XCTAssertNotNil(self.router.onDismiss)
+        }
+    }
+    
+    func testDismiss_notAnimated() {
+        // GIVEN
+        router = SpyRouter()
+        coordinator = OtherCoordinator(router: router)
+        
+        // WHEN
+        coordinator.dismiss(animated: false)
+        
+        // THEN
+        XCTAssertTrue(coordinator.children.isEmpty)
+        XCTAssertEqual(router.state, .dismissed)
+        XCTAssertNil(router.viewController)
+        XCTAssertFalse(router.animated ?? true)
+        XCTAssertNil(router.onDismiss)
+    }
+    
+    func testDismiss_animated() {
+        // GIVEN
+        router = SpyRouter()
+        coordinator = OtherCoordinator(router: router)
+        
+        // WHEN
+        coordinator.dismiss(animated: true)
+        
+        // THEN
+        XCTAssertTrue(coordinator.children.isEmpty)
+        XCTAssertEqual(router.state, .dismissed)
+        XCTAssertNil(router.viewController)
+        XCTAssertTrue(router.animated ?? false)
+        XCTAssertNil(router.onDismiss)
+    }
+    
+}