Add Manager's UT

Sources/TestUnitaires/TU_Manager.cs

@@ -0,0 +1,36 @@
+using Model;
+using Model.Stub;
+using Newtonsoft.Json.Linq;
+using NuGet.Frameworks;
+using System;
+
+namespace TestUnitaires
+{
+
+    public class TU_Manager
+    {
+        [Theory]
+        [InlineData(null)]
+        [InlineData("Réference")]
+        public void TU_Methods(string? test)
+        {
+            Playlist p = new Playlist(test, "PlaceHolder", "place.holder");
+            Album album = new Album(test, "place.holder", new Artiste("test"), "PlaceHolder", "PlaceHolder");
+            Title t = new Title(test, "test. mp3", "Banger");
+            Manager m = new Manager();
+            m.AddTitle(t);
+            m.AddPlaylist(p);
+            m.AddAlbum(album);
+            Assert.Contains(t, m.Titles);
+            Assert.Contains(album, m.Albums);
+            Assert.Contains(p, m.Playlists);
+            m.RemovePlaylist(p);
+            m.RemoveAlbum(album);
+            m.RemoveTitle(t);
+            Assert.DoesNotContain(t, m.Titles);
+            Assert.DoesNotContain(p, m.Playlists);
+            Assert.DoesNotContain(album, m.Albums);
+        }
+    }
+    
+}