Updated the ContentView view in the app target to support navigation split view and to show floating new task button on both sidebar and details views when required.

UnitTests/Tests/View Models/ContentViewModelTests.swift

@@ -1,3 +1,4 @@
+import SwiftUI
 import Testing
 
 @testable import Todos
@@ -16,11 +17,37 @@ struct ContentViewModelTests {
 
         // THEN
         #expect(viewModel.newTaskShown == false)
+        #expect(viewModel.group == nil)
+    }
+
+    // MARK: - Computed Property Tests
+
+    @Test(
+        "showNewTaskButtonInDetails returns expected value for every group",
+        arguments: zip(
+            [TodoGroup.today, .upcoming, .overdue, .completed, nil],
+            [true, true, true, false, false]
+        )
+    )
+    func showNewTaskButtonInDetails(
+        for group: TodoGroup?,
+        expects expectation: Bool
+    ) {
+        // GIVEN
+        let viewModel = ContentView.ViewModel()
+
+        viewModel.group = group
+
+        // WHEN
+        let shouldNewTaskButton = viewModel.showNewTaskButtonInDetails
+
+        // THEN
+        #expect(shouldNewTaskButton == expectation)
     }
 
     // MARK: - Functions Tests
 
-    @Test("showNewTask sets showNewTaskView to true")
+    @Test("showNewTask sets newTaskShown to true")
     func newTaskShown() {
         // GIVEN
         let viewModel = ContentView.ViewModel()
@@ -32,4 +59,25 @@ struct ContentViewModelTests {
         #expect(viewModel.newTaskShown == true)
     }
 
+    @Test(
+        "showNewTaskButtonInSidebar returns expected value for every horizontal size class",
+        arguments: zip(
+            [UserInterfaceSizeClass.compact, .regular, nil],
+            [true, false, false]
+        )
+    )
+    func showNewTaskButtonInSidebar(
+        for horizontalSizeClass: UserInterfaceSizeClass?,
+        expects expectation: Bool
+    ) {
+        // GIVEN
+        let viewModel = ContentView.ViewModel()
+
+        // WHEN
+        let shouldNewTaskButton = viewModel.showNewTaskButtonInSidebar(when: horizontalSizeClass)
+
+        // THEN
+        #expect(shouldNewTaskButton == expectation)
+    }
+
 }