✅ :: Add unit tests

2026-06-16 12:24:31 +00:00 · 2022-03-10 10:59:37 +01:00
parent 25de79f73d
commit dec430d951
7 changed files with 698 additions and 47 deletions
@@ -0,0 +1,125 @@
+//
+//  GradientLoadingBarViewModelTestCase.swift
+//  ExampleTests
+//
+//  Created by Felix Mau on 26.12.17.
+//  Copyright © 2017 Felix Mau. All rights reserved.
+//
+
+import XCTest
+import LightweightObservable
+
+@testable import GradientLoadingBar
+
+final class GradientLoadingBarViewModelTestCase: XCTestCase {
+    // MARK: - Private properties
+
+    private var sharedApplicationMock: SharedApplicationMock!
+    private var notificationCenter: NotificationCenter!
+
+    // MARK: - Public methods
+
+    override func setUp() {
+        super.setUp()
+
+        sharedApplicationMock = SharedApplicationMock()
+        notificationCenter = NotificationCenter()
+    }
+
+    override func tearDown() {
+        notificationCenter = nil
+        sharedApplicationMock = nil
+
+        super.tearDown()
+    }
+
+    // MARK: - Test observable `superview`
+
+    func test_initializer_shouldSetupSuperviewObservable_withNil() throws {
+        // When
+        let viewModel = GradientLoadingBarViewModel(sharedApplication: sharedApplicationMock,
+                                                    notificationCenter: notificationCenter)
+
+        // Then
+        let variable = try XCTUnwrap(viewModel.superview as? Variable, "Cast `Observable` instance to `Variable` in order to validate the initial value.")
+        XCTAssertNil(variable.value)
+    }
+
+    func test_initializer_shouldSetupSuperviewObservable_withKeyWindow() {
+        // Given
+        let keyWindow = KeyWindow()
+        let passiveWindow = PassiveWindow()
+        sharedApplicationMock.windows = [keyWindow, passiveWindow]
+
+        // When
+        let viewModel = GradientLoadingBarViewModel(sharedApplication: sharedApplicationMock,
+                                                    notificationCenter: notificationCenter)
+
+        // Then
+        XCTAssertEqual(viewModel.superview.value, keyWindow)
+    }
+
+    func test_initializer_shouldSetupSuperviewObservable_afterUIWindowDidBecomeKeyNotification() {
+        // Given
+        let keyWindow = KeyWindow()
+        let passiveWindow = PassiveWindow()
+        sharedApplicationMock.windows = [passiveWindow]
+
+        let viewModel = GradientLoadingBarViewModel(sharedApplication: sharedApplicationMock,
+                                                    notificationCenter: notificationCenter)
+
+        // When
+        sharedApplicationMock.windows.append(keyWindow)
+        notificationCenter.post(name: UIWindow.didBecomeKeyNotification,
+                                object: nil)
+
+        // Then
+        XCTAssertEqual(viewModel.superview.value, keyWindow)
+    }
+
+    func test_deinit_shouldResetSuperviewObservable_withNil() {
+        // Given
+        let keyWindow = KeyWindow()
+        let passiveWindow = PassiveWindow()
+        sharedApplicationMock.windows = [keyWindow, passiveWindow]
+
+        var viewModel: GradientLoadingBarViewModel? = GradientLoadingBarViewModel(sharedApplication: sharedApplicationMock,
+                                                                                  notificationCenter: notificationCenter)
+
+        let expectation = expectation(description: "Expected observer to be informed to reset superview to nil.")
+        var disposeBag = DisposeBag()
+
+        // As we've just initialized the view model it has to exist at this point, and therefore we can "safely" use force-unwrapping here.
+        // swiftlint:disable:next force_unwrapping
+        viewModel!.superview.subscribe { newSuperview, _ in
+            guard newSuperview == nil else {
+                // Skip initial call to observer.
+                return
+            }
+
+            expectation.fulfill()
+        }.disposed(by: &disposeBag)
+
+        // When
+        viewModel = nil
+
+        // Then
+        wait(for: [expectation], timeout: 0.1)
+    }
+}
+
+// MARK: - Helpers
+
+private final class KeyWindow: UIWindow {
+    override var isKeyWindow: Bool { true }
+}
+
+private final class PassiveWindow: UIWindow {
+    override var isKeyWindow: Bool { false }
+}
+
+// MARK: - Mocks
+
+private final class SharedApplicationMock: UIApplicationProtocol {
+    var windows = [UIWindow]()
+}