Clear user filter when item selected.

And add tests for `UserFilterViewModel`.

Author: grokys

src/GitHub.App/ViewModels/UserFilterViewModel.cs

@@ -25,8 +25,11 @@ public class UserFilterViewModel : ViewModelBase, IUserFilterViewModel
 
         public UserFilterViewModel(LoadPageDelegate load)
         {
+            Guard.ArgumentNotNull(load, nameof(load));
+
             this.load = load;
             this.WhenAnyValue(x => x.Filter).Subscribe(FilterChanged);
+            this.WhenAnyValue(x => x.Selected).Subscribe(_ => Filter = null);
             ClearSelection = ReactiveCommand.Create(
                 this.WhenAnyValue(x => x.Selected).Select(x => x != null))
                 .OnExecuteCompleted(_ => Selected = null);
@@ -96,7 +99,7 @@ void FilterChanged(string filter)
                 }
             }
 
-            usersView.Refresh();
+            UsersView.Refresh();
         }
 
         bool FilterUsers(object obj)

src/GitHub.VisualStudio/Views/UserFilterView.xaml

@@ -31,8 +31,12 @@
         <ListBox Background="Transparent"
                  BorderThickness="0"
                  ItemsSource="{Binding UsersView}"
-                 SelectedItem="{Binding Selected}"
                  ScrollViewer.HorizontalScrollBarVisibility="Disabled">
+            <ListBox.ItemContainerStyle>
+                <Style TargetType="ListBoxItem">
+                    <EventSetter Event="MouseLeftButtonUp" Handler="ListBoxItem_MouseLeftButtonUp"/>
+                </Style>
+            </ListBox.ItemContainerStyle>
             <ListBox.ItemTemplate>
                 <DataTemplate>
                     <DockPanel>

src/GitHub.VisualStudio/Views/UserFilterView.xaml.cs

@@ -1,11 +1,11 @@
 using System;
+using System.Windows;
 using System.Windows.Controls;
+using System.Windows.Input;
+using GitHub.ViewModels;
 
 namespace GitHub.VisualStudio.Views
 {
-    /// <summary>
-    /// Interaction logic for UserFilterView.xaml
-    /// </summary>
     public partial class UserFilterView : UserControl
     {
         public UserFilterView()
@@ -14,5 +14,15 @@ public UserFilterView()
         }
 
         public void FocusSearchBox() => searchBox.Focus();
+
+        private void ListBoxItem_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
+        {
+            var fe = e.Source as FrameworkElement;
+
+            if (fe?.DataContext is IActorViewModel vm)
+            {
+                ((IUserFilterViewModel)DataContext).Selected = vm;
+            }
+        }
     }
 }

test/GitHub.App.UnitTests/GitHub.App.UnitTests.csproj

@@ -190,6 +190,7 @@
     <Compile Include="ViewModels\GitHubPane\PullRequestUserReviewsViewModelTests.cs" />
     <Compile Include="ViewModels\TeamExplorer\RepositoryPublishViewModelTests.cs" />
     <Compile Include="Substitutes.cs" />
+    <Compile Include="ViewModels\UserFilterViewModelTests.cs" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\..\submodules\akavache\Akavache\Akavache_Net45.csproj">

test/GitHub.App.UnitTests/ViewModels/UserFilterViewModelTests.cs

@@ -0,0 +1,98 @@
+using System;
+using System.Linq;
+using System.Threading.Tasks;
+using System.Windows.Data;
+using GitHub.Models;
+using GitHub.ViewModels;
+using NUnit.Framework;
+
+namespace GitHub.App.UnitTests.ViewModels
+{
+    public class UserFilterViewModelTests
+    {
+        [Test]
+        public void Accessing_Users_Load_Users()
+        {
+            var target = CreateTarget();
+
+            Assert.That(target.Users.Count, Is.EqualTo(5));
+        }
+
+        [Test]
+        public void Setting_Filter_Adds_Ersatz_User()
+        {
+            var target = CreateTarget();
+            var view = (ListCollectionView)target.UsersView;
+
+            target.Filter = "grok";
+
+            Assert.That(target.Users.Count, Is.EqualTo(6));
+            Assert.That(target.Users.Last().Login, Is.EqualTo("grok"));
+            Assert.That(((IActorViewModel)view.GetItemAt(0)).Login, Is.EqualTo("grok"));
+        }
+
+        [Test]
+        public void Changing_Filter_Updates_Ersatz_User()
+        {
+            var target = CreateTarget();
+            var view = (ListCollectionView)target.UsersView;
+
+            target.Filter = "grok";
+
+            Assert.That(target.Users.Count, Is.EqualTo(6));
+            Assert.That(target.Users.Last().Login, Is.EqualTo("grok"));
+
+            target.Filter = "shan";
+
+            Assert.That(target.Users.Count, Is.EqualTo(6));
+            Assert.That(target.Users.Last().Login, Is.EqualTo("shan"));
+        }
+
+        [Test]
+        public void Changing_Filter_To_Existing_User_Removes_Ersatz_User()
+        {
+            var target = CreateTarget();
+            var view = (ListCollectionView)target.UsersView;
+
+            target.Filter = "grok";
+
+            Assert.That(target.Users.Count, Is.EqualTo(6));
+            Assert.That(target.Users.Last().Login, Is.EqualTo("grok"));
+
+            target.Filter = "shana";
+
+            Assert.That(target.Users.Count, Is.EqualTo(5));
+        }
+
+        [Test]
+        public void Selecting_User_Clears_Filter()
+        {
+            var target = CreateTarget();
+
+            target.Filter = "grok";
+            target.Selected = target.Users[1];
+
+            Assert.Null(target.Filter);
+        }
+
+        static UserFilterViewModel CreateTarget(UserFilterViewModel.LoadPageDelegate load = null)
+        {
+            Task<Page<ActorModel>> LoadPage(string after) => Task.FromResult(new Page<ActorModel>
+            {
+                TotalCount = 5,
+                Items = new[]
+                {
+                    new ActorModel { Login = "grokys" },
+                    new ActorModel { Login = "jcansdale" },
+                    new ActorModel { Login = "meaghanlewis" },
+                    new ActorModel { Login = "shana" },
+                    new ActorModel { Login = "StanleyGoldman" },
+                },
+            });
+
+            load = load ?? LoadPage;
+
+            return new UserFilterViewModel(load);
+        }
+    }
+}