diff --git a/Selector.Tests/Consumer/AudioInjector.cs b/Selector.Tests/Consumer/AudioInjector.cs
new file mode 100644
index 0000000..70b3727
--- /dev/null
+++ b/Selector.Tests/Consumer/AudioInjector.cs
@@ -0,0 +1,102 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using Xunit;
+using Moq;
+using FluentAssertions;
+using SpotifyAPI.Web;
+
+using Selector;
+
+namespace Selector.Tests
+{
+    public class AudioInjectorTests
+    {
+        [Fact]
+        public void Subscribe()
+        {
+            var watcherMock = new Mock<IPlayerWatcher>();
+            var spotifyMock = new Mock<ITracksClient>();
+
+            var featureInjector = new AudioFeatureInjector(watcherMock.Object, spotifyMock.Object);
+
+            featureInjector.Subscribe();
+
+            watcherMock.VerifyAdd(m => m.ItemChange += It.IsAny<EventHandler<ListeningChangeEventArgs>>());
+        }
+
+        [Fact]
+        public void Unsubscribe()
+        {
+            var watcherMock = new Mock<IPlayerWatcher>();
+            var spotifyMock = new Mock<ITracksClient>();
+
+            var featureInjector = new AudioFeatureInjector(watcherMock.Object, spotifyMock.Object);
+
+            featureInjector.Unsubscribe();
+
+            watcherMock.VerifyRemove(m => m.ItemChange -= It.IsAny<EventHandler<ListeningChangeEventArgs>>());
+        }
+
+        [Fact]
+        public void SubscribeFuncArg()
+        {
+            var watcherMock = new Mock<IPlayerWatcher>();
+            var watcherFuncArgMock = new Mock<IPlayerWatcher>();
+            var spotifyMock = new Mock<ITracksClient>();
+
+            var featureInjector = new AudioFeatureInjector(watcherMock.Object, spotifyMock.Object);
+
+            featureInjector.Subscribe(watcherFuncArgMock.Object);
+
+            watcherFuncArgMock.VerifyAdd(m => m.ItemChange += It.IsAny<EventHandler<ListeningChangeEventArgs>>());
+            watcherMock.VerifyNoOtherCalls();
+        }
+
+        [Fact]
+        public void UnsubscribeFuncArg()
+        {
+            var watcherMock = new Mock<IPlayerWatcher>();
+            var watcherFuncArgMock = new Mock<IPlayerWatcher>();
+            var spotifyMock = new Mock<ITracksClient>();
+
+            var featureInjector = new AudioFeatureInjector(watcherMock.Object, spotifyMock.Object);
+
+            featureInjector.Unsubscribe(watcherFuncArgMock.Object);
+
+            watcherFuncArgMock.VerifyRemove(m => m.ItemChange -= It.IsAny<EventHandler<ListeningChangeEventArgs>>());
+            watcherMock.VerifyNoOtherCalls();
+        }
+
+        [Fact]
+        public async void Callback()
+        {
+            var watcherMock = new Mock<IPlayerWatcher>();
+            var spotifyMock = new Mock<ITracksClient>();
+            var timelineMock = new Mock<AnalysedTrackTimeline>();
+            var eventArgsMock = new Mock<ListeningChangeEventArgs>();
+            var playingMock = new Mock<CurrentlyPlayingContext>();
+            var trackMock = new Mock<FullTrack>();
+            var featureMock = new Mock<TrackAudioFeatures>();
+
+            eventArgsMock.Object.Current = playingMock.Object;
+            playingMock.Object.Item = trackMock.Object;
+
+            spotifyMock.Setup(m => m.GetAudioFeatures(It.IsAny<string>()).Result).Returns(() => featureMock.Object);
+
+            var featureInjector = new AudioFeatureInjector(watcherMock.Object, spotifyMock.Object)
+            {
+                Timeline = timelineMock.Object
+            };
+
+            await featureInjector.AsyncCallback(eventArgsMock.Object);
+
+            spotifyMock.Verify(m => m.GetAudioFeatures(It.IsAny<string>()));
+            spotifyMock.VerifyNoOtherCalls();
+
+            timelineMock.Verify(m => m.Add(It.IsAny<AnalysedTrack>(), It.IsAny<DateTime>()), Times.Once);
+            timelineMock.VerifyNoOtherCalls();
+        }
+    }
+}
diff --git a/Selector.Tests/Consumer/AudioInjectorFactory.cs b/Selector.Tests/Consumer/AudioInjectorFactory.cs
new file mode 100644
index 0000000..60085cc
--- /dev/null
+++ b/Selector.Tests/Consumer/AudioInjectorFactory.cs
@@ -0,0 +1,31 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using Microsoft.Extensions.Logging;
+using Xunit;
+using Moq;
+using FluentAssertions;
+using SpotifyAPI.Web;
+
+using Selector;
+
+namespace Selector.Tests
+{
+    public class AudioInjectorFactoryTests
+    {
+        [Fact]
+        public void Get()
+        {
+            var logMock = new Mock<ILoggerFactory>();
+            var configFactoryMock = new Mock<ISpotifyConfigFactory>();
+
+            var factory = new AudioFeatureInjectorFactory(logMock.Object);
+
+            var consumer = factory.Get(configFactoryMock.Object);
+
+            configFactoryMock.Verify(m => m.GetConfig(), Times.Once);
+            consumer.Should().NotBeNull();
+        }
+    }
+}
diff --git a/Selector.Tests/Equal.cs b/Selector.Tests/Equality/Equal.cs
similarity index 100%
rename from Selector.Tests/Equal.cs
rename to Selector.Tests/Equality/Equal.cs
diff --git a/Selector.Tests/UriEqual.cs b/Selector.Tests/Equality/UriEqual.cs
similarity index 100%
rename from Selector.Tests/UriEqual.cs
rename to Selector.Tests/Equality/UriEqual.cs
diff --git a/Selector.Tests/Spotify/Providers.cs b/Selector.Tests/Spotify/Providers.cs
new file mode 100644
index 0000000..593a2ca
--- /dev/null
+++ b/Selector.Tests/Spotify/Providers.cs
@@ -0,0 +1,50 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using Microsoft.Extensions.Logging;
+using Xunit;
+using Moq;
+using FluentAssertions;
+using SpotifyAPI.Web;
+
+using Selector;
+
+namespace Selector.Tests
+{
+    public class RefreshTokenFactoryProviderTests
+    {
+        [Fact]
+        public void Init()
+        {
+            var provider = new RefreshTokenFactoryProvider();
+
+            provider.Initialised.Should().BeFalse();
+
+            provider.Initialise("a", "b");
+            
+            provider.Initialised.Should().BeTrue();
+
+            provider.Initialise("a", "");
+
+            provider.Initialised.Should().BeFalse();
+
+            provider.Initialise(null, "b");
+
+            provider.Initialised.Should().BeFalse();
+        }
+
+        [Fact]
+        public void Get()
+        {
+            var provider = new RefreshTokenFactoryProvider();
+
+            provider.Initialise("a", "b");
+            
+            var consumer = provider.GetFactory("a");
+
+            consumer.Should().NotBeNull();
+            consumer.Result.Should().NotBeNull();
+        }
+    }
+}
diff --git a/Selector.Tests/PlayerTimeline.cs b/Selector.Tests/Timeline/PlayerTimeline.cs
similarity index 100%
rename from Selector.Tests/PlayerTimeline.cs
rename to Selector.Tests/Timeline/PlayerTimeline.cs
diff --git a/Selector/Consumers/AudioFeatureInjector.cs b/Selector/Consumers/AudioFeatureInjector.cs
index 2e12910..18d5d9f 100644
--- a/Selector/Consumers/AudioFeatureInjector.cs
+++ b/Selector/Consumers/AudioFeatureInjector.cs
@@ -38,7 +38,7 @@ namespace Selector
             Task.Run(() => { return AsyncCallback(e); }, CancelToken);
         }
 
-        private async Task AsyncCallback(ListeningChangeEventArgs e)
+        public async Task AsyncCallback(ListeningChangeEventArgs e)
         {
             if (e.Current.Item is FullTrack track)
             {
diff --git a/Selector/Helpers/SpotifyExtensions.cs b/Selector/Helpers/SpotifyExtensions.cs
index cbab6ec..abcb6da 100644
--- a/Selector/Helpers/SpotifyExtensions.cs
+++ b/Selector/Helpers/SpotifyExtensions.cs
@@ -9,11 +9,11 @@ namespace Selector
 {
     public static class SpotifyExtensions
     {
-        public static string DisplayString(this FullTrack track) => $"{track.Name} / {track.Album.Name} / {track.Artists.DisplayString()}";
-        public static string DisplayString(this SimpleAlbum album) => $"{album.Name} / {album.Artists.DisplayString()}";
+        public static string DisplayString(this FullTrack track) => $"{track.Name} / {track.Album?.Name} / {track.Artists?.DisplayString()}";
+        public static string DisplayString(this SimpleAlbum album) => $"{album.Name} / {album.Artists?.DisplayString()}";
         public static string DisplayString(this SimpleArtist artist) => artist.Name;
 
-        public static string DisplayString(this FullEpisode ep) => $"{ep.Name} / {ep.Show.DisplayString()}";
+        public static string DisplayString(this FullEpisode ep) => $"{ep.Name} / {ep.Show?.DisplayString()}";
         public static string DisplayString(this SimpleShow show) => $"{show.Name} / {show.Publisher}";
 
 
@@ -21,11 +21,11 @@ namespace Selector
             
             if (currentPlaying.Item is FullTrack track)
             {
-                return $"{currentPlaying.IsPlaying}, {track.DisplayString()}, {currentPlaying.Device.DisplayString()}";
+                return $"{currentPlaying.IsPlaying}, {track.DisplayString()}, {currentPlaying.Device?.DisplayString()}";
             }
             else if (currentPlaying.Item is FullEpisode episode)
             {
-                return $"{currentPlaying.IsPlaying}, {episode.DisplayString()}, {currentPlaying.Device.DisplayString()}";
+                return $"{currentPlaying.IsPlaying}, {episode.DisplayString()}, {currentPlaying.Device?.DisplayString()}";
             }
             else
             {