Apply suggestions from code review

Co-authored-by: David Pine <david.pine@microsoft.com>

src/Services/ListenTogether/ListenTogether.Application/Grains/RoomGrain.cs

@@ -6,52 +6,52 @@ using Orleans.Runtime;
 
 namespace ListenTogether.Application.Grains
 {
-    public class RoomGrain : Grain, IRoomGrain
+    public sealed class RoomGrain : Grain, IRoomGrain
     {
-        IPersistentState<Room> Room { get; set; }
-        public ILogger<RoomGrain> Logger { get; }
+        private readonly IPersistentState<Room> _room;
+        private readonly ILogger<RoomGrain> _logger;
 
         public RoomGrain([PersistentState("room", "roomStorage")] IPersistentState<Room> room,
             ILogger<RoomGrain> logger)
         {
-            Room = room;
-            Logger = logger;
+            _room = room;
+            _logger = logger;
         }
 
         public async Task<Room> JoinRoom(string connectionId, string userName)
         {
-            Logger.LogInformation($"User {userName} is joining {Room.State.Code}, listening to {Room.State.Episode.Show.Title}");
-            Room.State.AddUser(new User(connectionId, userName));
-            await Room.WriteStateAsync();
-            return Room.State;
+            _logger.LogInformation($"User {userName} is joining {_room.State.Code}, listening to {_room.State.Episode.Show.Title}");
+            _room.State.AddUser(new User(connectionId, userName));
+            await _room.WriteStateAsync();
+            return _room.State;
         }
 
         public async Task<Room> LeaveRoom(string connectionId)
         {
-            var user = Room.State.Users.First(x => x.ConnectionId == connectionId);
-            Logger.LogInformation($"User {user.Name} is joining {Room.State.Code}, listening to {Room.State.Episode.Show.Title}");
-            Room.State.RemoveUser(connectionId);
-            await Room.WriteStateAsync();
+            var user = _room.State.Users.First(_ => _.ConnectionId == connectionId);
+            _logger.LogInformation($"User {user.Name} is joining {_room.State.Code}, listening to {_room.State.Episode.Show.Title}");
+            _room.State.RemoveUser(connectionId);
+            await _room.WriteStateAsync();
 
-            if(Room.State.Users.Count == 0)
+            if (_room.State.Users.Count is 0)
             {
                 base.DeactivateOnIdle();
             }
 
-            return Room.State;
+            return _room.State;
         }
 
         public async Task SetRoom(Room room)
         {
-            Room.State = room;
-            await Room.WriteStateAsync();
+            _room.State = room;
+            await _room.WriteStateAsync();
         }
 
         public Task<Room> UpdatePlayerState(TimeSpan seconds, PlayerState playerState)
         {
-            Logger.LogInformation($"Updating player state to {playerState} at {seconds}.");
-            Room.State.UpdatePlayerState(seconds, playerState);
-            return Task.FromResult(Room.State);
+            _logger.LogInformation($"Updating player state to {playerState} at {seconds}.");
+            _room.State.UpdatePlayerState(seconds, playerState);
+            return Task.FromResult(_room.State);
         }
     }
 }

src/Services/ListenTogether/ListenTogether.Application/Interfaces/IRoomGrain.cs

@@ -1,13 +1,12 @@
 using ListenTogether.Domain;
 using Orleans;
 
-namespace ListenTogether.Application.Interfaces
+namespace ListenTogether.Application.Interfaces;
+
+public interface IRoomGrain : IGrainWithStringKey
 {
-    public interface IRoomGrain : IGrainWithStringKey
-    {
-        Task SetRoom(Room room);
-        Task<Room> JoinRoom(string connectionId, string userName);
-        Task<Room> LeaveRoom(string connectionId);
-        Task<Room> UpdatePlayerState(TimeSpan seconds, PlayerState playerState);
-    }
+    Task SetRoom(Room room);
+    Task<Room> JoinRoom(string connectionId, string userName);
+    Task<Room> LeaveRoom(string connectionId);
+    Task<Room> UpdatePlayerState(TimeSpan seconds, PlayerState playerState);
 }

src/Services/ListenTogether/ListenTogether.Domain/Room.cs

@@ -4,7 +4,7 @@ public class Room
 {
     private const int Length = 5;
     private const string ValidCharacters = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
-    private readonly Random _randGenerator = new();
+    private readonly Random _randGenerator = Random.Shared;
 
     public Room () 
     {

src/Services/Podcasts/Podcast.Ingestion.Worker/PodcastIngestionHandler.cs

@@ -28,7 +28,7 @@ public class PodcastIngestionHandler : IPodcastIngestionHandler
         CancellationToken stoppingToken)
     {
         _logger.LogInformation($"The show {title} at {url} was received by the ingestion worker.");
-        var isExistingShow = await _podcastDbContext.Feeds.AnyAsync(feed => feed.Url.ToLower() == url.ToLower(), stoppingToken);
+        var isExistingShow = await _podcastDbContext.Feeds.AnyAsync(feed => string.Equals(feed.Url, url, StringComparison.OrdinalIgnoreCase), stoppingToken);
         if (isExistingShow) 
             return;
 
@@ -37,19 +37,9 @@ public class PodcastIngestionHandler : IPodcastIngestionHandler
         if (!isAcceptedTopic)
         {
             _logger.LogInformation($"The show {title} at {url} was not automatically approved.");
-            var categoryStringArray = string.Empty;
-            foreach (var cat in feedCategories)
-            {
-                categoryStringArray += $"{cat},";
-            }
-
-            if(categoryStringArray.Contains(","))
-            {
-                categoryStringArray = categoryStringArray.Substring(0, categoryStringArray.LastIndexOf(','));
-            }
-
             // Must be manually approved
-            var userFeed = new UserSubmittedFeed(title, url, categoryStringArray);
+            var userFeed = new UserSubmittedFeed(
+                title, url, string.Join(",", feedCategories));
             await _podcastDbContext.UserSubmittedFeeds.AddAsync(userFeed, stoppingToken);
             await _podcastDbContext.SaveChangesAsync(stoppingToken);
             _logger.LogInformation($"The show {title} at {url} was saved as a user-submitted feed.");