List tasks feature (#4)

This PR contains the work done to implement the **List Tasks** feature, and to integrate it into the main content view of the app.

Reviewed-on: rock-n-code/todos-app#4
Co-authored-by: Javier Cicchelli <javier@rock-n-code.com>
Co-committed-by: Javier Cicchelli <javier@rock-n-code.com>

UnitTests/Tests/View Models/NewTaskViewModelTests.swift

@@ -124,10 +124,7 @@ struct NewTaskViewModelTests {
     @MainActor
     func saveWithAllProperties() throws {
         // GIVEN
-        let container = try ModelContainer(
-            for: Todo.self,
-            configurations: .init(isStoredInMemoryOnly: true)
-        )
+        let container = try modelContainer
         let context = container.mainContext
         let viewModel = NewTaskView.ViewModel()
 
@@ -153,10 +150,7 @@ struct NewTaskViewModelTests {
     @MainActor
     func saveWithEmptyNote() throws {
         // GIVEN
-        let container = try ModelContainer(
-            for: Todo.self,
-            configurations: .init(isStoredInMemoryOnly: true)
-        )
+        let container = try modelContainer
         let context = container.mainContext
         let viewModel = NewTaskView.ViewModel()
 
@@ -182,10 +176,7 @@ struct NewTaskViewModelTests {
     @MainActor
     func saveWithWhitespaceNote() throws {
         // GIVEN
-        let container = try ModelContainer(
-            for: Todo.self,
-            configurations: .init(isStoredInMemoryOnly: true)
-        )
+        let container = try modelContainer
         let context = container.mainContext
         let viewModel = NewTaskView.ViewModel()
 
@@ -211,10 +202,7 @@ struct NewTaskViewModelTests {
     @MainActor
     func saveMultipleTodos() throws {
         // GIVEN
-        let container = try ModelContainer(
-            for: Todo.self,
-            configurations: .init(isStoredInMemoryOnly: true)
-        )
+        let container = try modelContainer
         let context = container.mainContext
         let viewModelFirst = NewTaskView.ViewModel()
         let viewModelSecond = NewTaskView.ViewModel()
@@ -237,3 +225,20 @@ struct NewTaskViewModelTests {
     }
 
 }
+
+// MARK: - Helpers
+
+private extension NewTaskViewModelTests {
+    
+    // MARK: Computed
+    
+    var modelContainer: ModelContainer {
+        get throws {
+            try ModelContainer(
+                for: Todo.self,
+                configurations: .init(isStoredInMemoryOnly: true)
+            )
+        }
+    }
+    
+}

UnitTests/Tests/View Models/TaskGroupListViewModelTests.swift

@@ -37,11 +37,10 @@ struct TaskGroupListViewModelTests {
     )
     func countWhenEmptyData(for group: TodoGroup) throws {
         // GIVEN
-        let tasks: [Todo] = []
         let viewModel = TaskGroupListView.ViewModel()
 
         // WHEN
-        let count = viewModel.count(tasks, for: group)
+        let count = viewModel.count(emptyTasks, for: group)
 
         // THEN
         #expect(count == 0)
@@ -53,13 +52,33 @@ struct TaskGroupListViewModelTests {
     )
     func countWhenFilledData(for group: TodoGroup) throws {
         // GIVEN
+        let viewModel = TaskGroupListView.ViewModel()
+
+        // WHEN
+        let count = viewModel.count(sampleTasks, for: group)
+
+        // THEN
+        #expect(count == 2)
+    }
+
+}
+
+// MARK: - Helpers
+
+private extension TaskGroupListViewModelTests {
+
+    // MARK: Computed
+    
+    var emptyTasks: [Todo] { [] }
+
+    var sampleTasks: [Todo] {
         let today: Date = .now
         let tomorrow = calendar.date(byAdding: .day, value: 1, to: today) ?? today
         let yesterday = calendar.date(byAdding: .day, value: -1, to: today) ?? today
         let nextWeek = calendar.date(byAdding: .day, value: 7, to: today) ?? today
         let lastWeek = calendar.date(byAdding: .day, value: -7, to: today) ?? today
 
-        let tasks = [
+        return [
             Todo(title: "Today task #1", due: today),
             Todo(title: "Today task #2", due: today),
             Todo(title: "Tomorrow task #1", due: tomorrow),
@@ -67,16 +86,8 @@ struct TaskGroupListViewModelTests {
             Todo(title: "Yesterday task #1", due: yesterday),
             Todo(title: "Last week task #1", due: lastWeek),
             Todo(title: "Completed task #1", due: tomorrow, completed: today),
-            Todo(title: "Completed task #2", due: yesterday, completed: today)
+            Todo(title: "Completed task #2", due: yesterday, completed: today),
         ]
-
-        let viewModel = TaskGroupListView.ViewModel()
-
-        // WHEN
-        let count = viewModel.count(tasks, for: group)
-
-        // THEN
-        #expect(count == 2)
     }
 
 }

UnitTests/Tests/View Models/TaskListViewModelTests.swift

@@ -0,0 +1,27 @@
+import Foundation
+import SwiftData
+import Testing
+
+@testable import Todos
+
+@Suite("TaskList view model tests")
+struct TaskListViewModelTests {
+
+    // MARK: Computed tests
+
+    @Test(
+        "navigationTitle returns correct title for each and every group",
+        arguments: TodoGroup.allCases
+    )
+    func navigationTitle(for group: TodoGroup) {
+        // GIVEN
+        let viewModel = TaskListView.ViewModel(group: group)
+
+        // WHEN
+        let title = viewModel.navigationTitle
+
+        // THEN
+        #expect(title == group.title)
+    }
+
+}