More warning fixes

3 files changed, 27 insertions, 54 deletions

diff --git a/MediaBrowser.Providers/Manager/ProviderManager.cs b/MediaBrowser.Providers/Manager/ProviderManager.cs
index f26087fda3..860ea13cf6 100644
--- a/MediaBrowser.Providers/Manager/ProviderManager.cs
+++ b/MediaBrowser.Providers/Manager/ProviderManager.cs
@@ -942,10 +942,7 @@ namespace MediaBrowser.Providers.Manager
                 _activeRefreshes[id] = 0;
             }
 
-            if (RefreshStarted != null)
-            {
-                RefreshStarted(this, new GenericEventArgs<BaseItem>(item));
-            }
+            RefreshStarted?.Invoke(this, new GenericEventArgs<BaseItem>(item));
         }
 
         public void OnRefreshComplete(BaseItem item)
@@ -956,10 +953,7 @@ namespace MediaBrowser.Providers.Manager
                 _activeRefreshes.Remove(item.Id);
             }
 
-            if (RefreshCompleted != null)
-            {
-                RefreshCompleted(this, new GenericEventArgs<BaseItem>(item));
-            }
+            RefreshCompleted?.Invoke(this, new GenericEventArgs<BaseItem>(item));
         }
 
         public double? GetRefreshProgress(Guid id)
@@ -986,10 +980,7 @@ namespace MediaBrowser.Providers.Manager
                 {
                     _activeRefreshes[id] = progress;
 
-                    if (RefreshProgress != null)
-                    {
-                        RefreshProgress(this, new GenericEventArgs<Tuple<BaseItem, double>>(new Tuple<BaseItem, double>(item, progress)));
-                    }
+                    RefreshProgress?.Invoke(this, new GenericEventArgs<Tuple<BaseItem, double>>(new Tuple<BaseItem, double>(item, progress)));
                 }
                 else
                 {
@@ -1079,17 +1070,14 @@ namespace MediaBrowser.Providers.Manager
             await item.RefreshMetadata(options, cancellationToken).ConfigureAwait(false);
 
             // Collection folders don't validate their children so we'll have to simulate that here
-            var collectionFolder = item as CollectionFolder;
 
-            if (collectionFolder != null)
+            if (item is CollectionFolder collectionFolder)
             {
                 await RefreshCollectionFolderChildren(options, collectionFolder, cancellationToken).ConfigureAwait(false);
             }
             else
             {
-                var folder = item as Folder;
-
-                if (folder != null)
+                if (item is Folder folder)
                 {
                     await folder.ValidateChildren(new SimpleProgress<double>(), cancellationToken, options).ConfigureAwait(false);
                 }
@@ -1098,16 +1086,11 @@ namespace MediaBrowser.Providers.Manager
 
         private async Task RefreshCollectionFolderChildren(MetadataRefreshOptions options, CollectionFolder collectionFolder, CancellationToken cancellationToken)
         {
-            foreach (var child in collectionFolder.GetPhysicalFolders().ToList())
+            foreach (var child in collectionFolder.GetPhysicalFolders())
             {
                 await child.RefreshMetadata(options, cancellationToken).ConfigureAwait(false);
 
-                if (child.IsFolder)
-                {
-                    var folder = (Folder)child;
-
-                    await folder.ValidateChildren(new SimpleProgress<double>(), cancellationToken, options, true).ConfigureAwait(false);
-                }
+                await child.ValidateChildren(new SimpleProgress<double>(), cancellationToken, options, true).ConfigureAwait(false);
             }
         }
 
@@ -1116,20 +1099,18 @@ namespace MediaBrowser.Providers.Manager
             var albums = _libraryManagerFactory()
                 .GetItemList(new InternalItemsQuery
                 {
-                    IncludeItemTypes = new[] { typeof(MusicAlbum).Name },
+                    IncludeItemTypes = new[] { nameof(MusicAlbum) },
                     ArtistIds = new[] { item.Id },
                     DtoOptions = new DtoOptions(false)
                     {
                         EnableImages = false
                     }
                 })
-                .OfType<MusicAlbum>()
-                .ToList();
+                .OfType<MusicAlbum>();
 
             var musicArtists = albums
                 .Select(i => i.MusicArtist)
-                .Where(i => i != null)
-                .ToList();
+                .Where(i => i != null);
 
             var musicArtistRefreshTasks = musicArtists.Select(i => i.ValidateChildren(new SimpleProgress<double>(), cancellationToken, options, true));
 
diff --git a/MediaBrowser.Providers/Music/MusicBrainzAlbumProvider.cs b/MediaBrowser.Providers/Music/MusicBrainzAlbumProvider.cs
index aee9921034..f86cdeab9f 100644
--- a/MediaBrowser.Providers/Music/MusicBrainzAlbumProvider.cs
+++ b/MediaBrowser.Providers/Music/MusicBrainzAlbumProvider.cs
@@ -53,7 +53,7 @@ namespace MediaBrowser.Providers.Music
             var releaseId = searchInfo.GetReleaseId();
             var releaseGroupId = searchInfo.GetReleaseGroupId();
 
-            string url = null;
+            string url;
             var isNameSearch = false;
             bool forceMusicBrainzProper = false;
 
@@ -100,10 +100,10 @@ namespace MediaBrowser.Providers.Music
                 }
             }
 
-            return new List<RemoteSearchResult>();
+            return Enumerable.Empty<RemoteSearchResult>();
         }
 
-        private List<RemoteSearchResult> GetResultsFromResponse(Stream stream)
+        private IEnumerable<RemoteSearchResult> GetResultsFromResponse(Stream stream)
         {
             using (var oReader = new StreamReader(stream, Encoding.UTF8))
             {
@@ -149,7 +149,7 @@ namespace MediaBrowser.Providers.Music
 
                         return result;
 
-                    }).ToList();
+                    });
                 }
             }
         }
@@ -301,7 +301,7 @@ namespace MediaBrowser.Providers.Music
 
             public List<ValueTuple<string, string>> Artists = new List<ValueTuple<string, string>>();
 
-            public static List<ReleaseResult> Parse(XmlReader reader)
+            public static IEnumerable<ReleaseResult> Parse(XmlReader reader)
             {
                 reader.MoveToContent();
                 reader.Read();
@@ -338,13 +338,11 @@ namespace MediaBrowser.Providers.Music
                     }
                 }
 
-                return new List<ReleaseResult>();
+                return Enumerable.Empty<ReleaseResult>();
             }
 
-            private static List<ReleaseResult> ParseReleaseList(XmlReader reader)
+            private static IEnumerable<ReleaseResult> ParseReleaseList(XmlReader reader)
             {
-                var list = new List<ReleaseResult>();
-
                 reader.MoveToContent();
                 reader.Read();
 
@@ -369,7 +367,7 @@ namespace MediaBrowser.Providers.Music
                                         var release = ParseRelease(subReader, releaseId);
                                         if (release != null)
                                         {
-                                            list.Add(release);
+                                            yield return release;
                                         }
                                     }
                                     break;
@@ -386,8 +384,6 @@ namespace MediaBrowser.Providers.Music
                         reader.Read();
                     }
                 }
-
-                return list;
             }
 
             private static ReleaseResult ParseRelease(XmlReader reader, string releaseId)
@@ -552,7 +548,7 @@ namespace MediaBrowser.Providers.Music
             return (null, null);
         }
 
-        private static ValueTuple<string, string> ParseArtistArtistCredit(XmlReader reader, string artistId)
+        private static (string name, string id) ParseArtistArtistCredit(XmlReader reader, string artistId)
         {
             reader.MoveToContent();
             reader.Read();
@@ -586,7 +582,7 @@ namespace MediaBrowser.Providers.Music
                 }
             }
 
-            return new ValueTuple<string, string>(name, artistId);
+            return (name, artistId);
         }
 
         private async Task<string> GetReleaseIdFromReleaseGroupId(string releaseGroupId, CancellationToken cancellationToken)
diff --git a/MediaBrowser.Providers/Music/MusicBrainzArtistProvider.cs b/MediaBrowser.Providers/Music/MusicBrainzArtistProvider.cs
index 924b712507..55aab7778a 100644
--- a/MediaBrowser.Providers/Music/MusicBrainzArtistProvider.cs
+++ b/MediaBrowser.Providers/Music/MusicBrainzArtistProvider.cs
@@ -50,7 +50,7 @@ namespace MediaBrowser.Providers.Music
                 {
                     using (var stream = response.Content)
                     {
-                        var results = GetResultsFromResponse(stream);
+                        var results = GetResultsFromResponse(stream).ToList();
 
                         if (results.Count > 0)
                         {
@@ -74,10 +74,10 @@ namespace MediaBrowser.Providers.Music
                 }
             }
 
-            return new List<RemoteSearchResult>();
+            return Enumerable.Empty<RemoteSearchResult>();
         }
 
-        private List<RemoteSearchResult> GetResultsFromResponse(Stream stream)
+        private IEnumerable<RemoteSearchResult> GetResultsFromResponse(Stream stream)
         {
             using (var oReader = new StreamReader(stream, Encoding.UTF8))
             {
@@ -126,15 +126,13 @@ namespace MediaBrowser.Providers.Music
                         }
                     }
 
-                    return new List<RemoteSearchResult>();
+                    return Enumerable.Empty<RemoteSearchResult>();
                 }
             }
         }
 
-        private List<RemoteSearchResult> ParseArtistList(XmlReader reader)
+        private IEnumerable<RemoteSearchResult> ParseArtistList(XmlReader reader)
         {
-            var list = new List<RemoteSearchResult>();
-
             reader.MoveToContent();
             reader.Read();
 
@@ -159,7 +157,7 @@ namespace MediaBrowser.Providers.Music
                                     var artist = ParseArtist(subReader, mbzId);
                                     if (artist != null)
                                     {
-                                        list.Add(artist);
+                                        yield return artist;
                                     }
                                 }
                                 break;
@@ -176,8 +174,6 @@ namespace MediaBrowser.Providers.Music
                     reader.Read();
                 }
             }
-
-            return list;
         }
 
         private RemoteSearchResult ParseArtist(XmlReader reader, string artistId)
@@ -277,7 +273,7 @@ namespace MediaBrowser.Providers.Music
         /// </summary>
         /// <param name="name">The name.</param>
         /// <returns>System.String.</returns>
-        private string UrlEncode(string name)
+        private static string UrlEncode(string name)
         {
             return WebUtility.UrlEncode(name);
         }