Round 2 of nullable checks

ArchiSteamFarm.CustomPlugins.ExamplePlugin/CatAPI.cs

@@ -48,7 +48,7 @@ namespace ArchiSteamFarm.CustomPlugins.ExamplePlugin {
 				throw new ArgumentNullException(nameof(response.Content.Link));
 			}
 
-			return Uri.EscapeUriString(response.Content.Link);
+			return Uri.EscapeUriString(response.Content!.Link!);
 		}
 
 		[SuppressMessage("ReSharper", "ClassCannotBeInstantiated")]

ArchiSteamFarm/ASF.cs

@@ -131,9 +131,7 @@ namespace ArchiSteamFarm {
 
 		internal static void InitGlobalConfig(GlobalConfig globalConfig) {
 			if (globalConfig == null) {
-				ArchiLogger.LogNullError(nameof(globalConfig));
-
-				return;
+				throw new ArgumentNullException(nameof(globalConfig));
 			}
 
 			if (GlobalConfig != null) {
@@ -150,11 +148,11 @@ namespace ArchiSteamFarm {
 			if (!string.IsNullOrEmpty(Program.NetworkGroup)) {
 				using MD5 hashingAlgorithm = MD5.Create();
 
-				networkGroupText = "-" + BitConverter.ToString(hashingAlgorithm.ComputeHash(Encoding.UTF8.GetBytes(Program.NetworkGroup))).Replace("-", "");
+				networkGroupText = "-" + BitConverter.ToString(hashingAlgorithm.ComputeHash(Encoding.UTF8.GetBytes(Program.NetworkGroup!))).Replace("-", "");
 			} else if (!string.IsNullOrEmpty(globalConfig.WebProxyText)) {
 				using MD5 hashingAlgorithm = MD5.Create();
 
-				networkGroupText = "-" + BitConverter.ToString(hashingAlgorithm.ComputeHash(Encoding.UTF8.GetBytes(globalConfig.WebProxyText))).Replace("-", "");
+				networkGroupText = "-" + BitConverter.ToString(hashingAlgorithm.ComputeHash(Encoding.UTF8.GetBytes(globalConfig.WebProxyText!))).Replace("-", "");
 			}
 
 			ConfirmationsSemaphore ??= OS.CreateCrossProcessSemaphore(nameof(ConfirmationsSemaphore) + networkGroupText);
@@ -174,9 +172,7 @@ namespace ArchiSteamFarm {
 
 		internal static void InitGlobalDatabase(GlobalDatabase globalDatabase) {
 			if (globalDatabase == null) {
-				ArchiLogger.LogNullError(nameof(globalDatabase));
-
-				return;
+				throw new ArgumentNullException(nameof(globalDatabase));
 			}
 
 			if (GlobalDatabase != null) {
@@ -250,7 +246,7 @@ namespace ArchiSteamFarm {
 					return null;
 				}
 
-				Version newVersion = new Version(releaseResponse.Tag);
+				Version newVersion = new Version(releaseResponse.Tag!);
 
 				ArchiLogger.LogGenericInfo(string.Format(Strings.UpdateVersionInfo, SharedInfo.Version, newVersion));
 
@@ -389,6 +385,10 @@ namespace ArchiSteamFarm {
 				return;
 			}
 
+			if (Bot.BotsComparer == null) {
+				throw new ArgumentNullException(nameof(Bot.BotsComparer));
+			}
+
 			FileSystemWatcher = new FileSystemWatcher(SharedInfo.ConfigDirectory) { NotifyFilter = NotifyFilters.FileName | NotifyFilters.LastWrite };
 
 			FileSystemWatcher.Changed += OnChanged;
@@ -858,7 +858,7 @@ namespace ArchiSteamFarm {
 					}
 
 					if (!Directory.Exists(directory)) {
-						Directory.CreateDirectory(directory);
+						Directory.CreateDirectory(directory!);
 					}
 
 					// We're not interested in extracting placeholder files (but we still want directories created for them, done above)

ArchiSteamFarm/ArchiHandler.cs

@@ -63,9 +63,7 @@ namespace ArchiSteamFarm {
 
 		public override void HandleMsg(IPacketMsg packetMsg) {
 			if ((packetMsg == null) || (Client == null)) {
-				ArchiLogger.LogNullError(nameof(packetMsg) + " || " + nameof(Client));
-
-				return;
+				throw new ArgumentNullException(nameof(packetMsg) + " || " + nameof(Client));
 			}
 
 			LastPacketReceived = DateTime.UtcNow;
@@ -119,12 +117,6 @@ namespace ArchiSteamFarm {
 				throw new ArgumentNullException(nameof(chatGroupID) + " || " + nameof(chatID) + " || " + nameof(timestamp));
 			}
 
-			if (Client == null) {
-				ArchiLogger.LogNullError(nameof(Client));
-
-				return;
-			}
-
 			if (!Client.IsConnected) {
 				return;
 			}
@@ -143,12 +135,6 @@ namespace ArchiSteamFarm {
 				throw new ArgumentNullException(nameof(steamID) + " || " + nameof(timestamp));
 			}
 
-			if (Client == null) {
-				ArchiLogger.LogNullError(nameof(Client));
-
-				return;
-			}
-
 			if (!Client.IsConnected) {
 				return;
 			}
@@ -166,12 +152,6 @@ namespace ArchiSteamFarm {
 				throw new ArgumentNullException(nameof(steamID));
 			}
 
-			if (Client == null) {
-				ArchiLogger.LogNullError(nameof(Client));
-
-				return;
-			}
-
 			if (!Client.IsConnected) {
 				return;
 			}
@@ -191,12 +171,6 @@ namespace ArchiSteamFarm {
 				throw new ArgumentNullException(nameof(steamID));
 			}
 
-			if (Client == null) {
-				ArchiLogger.LogNullError(nameof(Client));
-
-				return false;
-			}
-
 			if (!Client.IsConnected) {
 				return false;
 			}
@@ -221,12 +195,6 @@ namespace ArchiSteamFarm {
 				throw new ArgumentNullException(nameof(steamID));
 			}
 
-			if (Client == null) {
-				ArchiLogger.LogNullError(nameof(Client));
-
-				return 0;
-			}
-
 			if (!Client.IsConnected) {
 				return 0;
 			}
@@ -256,12 +224,6 @@ namespace ArchiSteamFarm {
 		}
 
 		internal async Task<uint?> GetLevel() {
-			if (Client == null) {
-				ArchiLogger.LogNullError(nameof(Client));
-
-				return null;
-			}
-
 			if (!Client.IsConnected) {
 				return null;
 			}
@@ -287,12 +249,6 @@ namespace ArchiSteamFarm {
 		}
 
 		internal async Task<HashSet<ulong>?> GetMyChatGroupIDs() {
-			if (Client == null) {
-				ArchiLogger.LogNullError(nameof(Client));
-
-				return null;
-			}
-
 			if (!Client.IsConnected) {
 				return null;
 			}
@@ -319,12 +275,6 @@ namespace ArchiSteamFarm {
 		}
 
 		internal async Task<CPrivacySettings?> GetPrivacySettings() {
-			if (Client == null) {
-				ArchiLogger.LogNullError(nameof(Client));
-
-				return null;
-			}
-
 			if (!Client.IsConnected) {
 				return null;
 			}
@@ -351,12 +301,6 @@ namespace ArchiSteamFarm {
 		}
 
 		internal async Task<string?> GetTradeToken() {
-			if (Client == null) {
-				ArchiLogger.LogNullError(nameof(Client));
-
-				return null;
-			}
-
 			if (!Client.IsConnected) {
 				return null;
 			}
@@ -387,12 +331,6 @@ namespace ArchiSteamFarm {
 				throw new ArgumentNullException(nameof(steamID));
 			}
 
-			if (Client == null) {
-				ArchiLogger.LogNullError(nameof(Client));
-
-				return null;
-			}
-
 			if (!Client.IsConnected) {
 				return null;
 			}
@@ -425,12 +363,6 @@ namespace ArchiSteamFarm {
 				throw new ArgumentNullException(nameof(chatGroupID));
 			}
 
-			if (Client == null) {
-				ArchiLogger.LogNullError(nameof(Client));
-
-				return false;
-			}
-
 			if (!Client.IsConnected) {
 				return false;
 			}
@@ -455,12 +387,6 @@ namespace ArchiSteamFarm {
 				throw new ArgumentNullException(nameof(gameIDs));
 			}
 
-			if (Client == null) {
-				ArchiLogger.LogNullError(nameof(Client));
-
-				return;
-			}
-
 			if (!Client.IsConnected) {
 				return;
 			}
@@ -509,12 +435,6 @@ namespace ArchiSteamFarm {
 				throw new ArgumentNullException(nameof(guestPassID));
 			}
 
-			if (Client == null) {
-				ArchiLogger.LogNullError(nameof(Client));
-
-				return null;
-			}
-
 			if (!Client.IsConnected) {
 				return null;
 			}
@@ -540,12 +460,6 @@ namespace ArchiSteamFarm {
 				throw new ArgumentNullException(nameof(key));
 			}
 
-			if (Client == null) {
-				ArchiLogger.LogNullError(nameof(Client));
-
-				return null;
-			}
-
 			if (!Client.IsConnected) {
 				return null;
 			}
@@ -571,12 +485,6 @@ namespace ArchiSteamFarm {
 				throw new ArgumentNullException(nameof(steamID));
 			}
 
-			if (Client == null) {
-				ArchiLogger.LogNullError(nameof(Client));
-
-				return false;
-			}
-
 			if (!Client.IsConnected) {
 				return false;
 			}
@@ -597,12 +505,6 @@ namespace ArchiSteamFarm {
 		}
 
 		internal void RequestItemAnnouncements() {
-			if (Client == null) {
-				ArchiLogger.LogNullError(nameof(Client));
-
-				return;
-			}
-
 			if (!Client.IsConnected) {
 				return;
 			}
@@ -616,12 +518,6 @@ namespace ArchiSteamFarm {
 				throw new ArgumentNullException(nameof(steamID) + " || " + nameof(message));
 			}
 
-			if (Client == null) {
-				ArchiLogger.LogNullError(nameof(Client));
-
-				return EResult.Invalid;
-			}
-
 			if (!Client.IsConnected) {
 				return EResult.NoConnection;
 			}
@@ -651,12 +547,6 @@ namespace ArchiSteamFarm {
 				throw new ArgumentNullException(nameof(chatGroupID) + " || " + nameof(chatID) + " || " + nameof(message));
 			}
 
-			if (Client == null) {
-				ArchiLogger.LogNullError(nameof(Client));
-
-				return EResult.Invalid;
-			}
-
 			if (!Client.IsConnected) {
 				return EResult.NoConnection;
 			}
@@ -685,12 +575,6 @@ namespace ArchiSteamFarm {
 				throw new ArgumentNullException(nameof(steamID));
 			}
 
-			if (Client == null) {
-				ArchiLogger.LogNullError(nameof(Client));
-
-				return EResult.Invalid;
-			}
-
 			if (!Client.IsConnected) {
 				return EResult.NoConnection;
 			}
@@ -718,12 +602,6 @@ namespace ArchiSteamFarm {
 				throw new ArgumentNullException(nameof(chatMode));
 			}
 
-			if (Client == null) {
-				ArchiLogger.LogNullError(nameof(Client));
-
-				return;
-			}
-
 			if (!Client.IsConnected) {
 				return;
 			}

ArchiSteamFarm/ArchiWebHandler.cs

@@ -245,7 +245,7 @@ namespace ArchiSteamFarm {
 					return null;
 				}
 
-				XmlNode appNode = xmlNode.SelectSingleNode("appID");
+				XmlNode? appNode = xmlNode.SelectSingleNode("appID");
 
 				if (appNode == null) {
 					Bot.ArchiLogger.LogNullError(nameof(appNode));
@@ -259,7 +259,7 @@ namespace ArchiSteamFarm {
 					return null;
 				}
 
-				XmlNode nameNode = xmlNode.SelectSingleNode("name");
+				XmlNode? nameNode = xmlNode.SelectSingleNode("name");
 
 				if (nameNode == null) {
 					Bot.ArchiLogger.LogNullError(nameof(nameNode));

ArchiSteamFarm/Bot.cs

@@ -102,15 +102,15 @@ namespace ArchiSteamFarm {
 
 		[JsonProperty]
 		[PublicAPI]
-		public uint GamesToRedeemInBackgroundCount => BotDatabase?.GamesToRedeemInBackgroundCount ?? 0;
+		public uint GamesToRedeemInBackgroundCount => BotDatabase.GamesToRedeemInBackgroundCount;
 
 		[JsonProperty]
 		[PublicAPI]
-		public bool HasMobileAuthenticator => BotDatabase?.MobileAuthenticator != null;
+		public bool HasMobileAuthenticator => BotDatabase.MobileAuthenticator != null;
 
 		[JsonProperty]
 		[PublicAPI]
-		public bool IsConnectedAndLoggedOn => SteamClient?.SteamID != null;
+		public bool IsConnectedAndLoggedOn => SteamClient.SteamID != null;
 
 		[JsonProperty]
 		[PublicAPI]
@@ -140,14 +140,11 @@ namespace ArchiSteamFarm {
 		private readonly SteamUser SteamUser;
 		private readonly Trading Trading;
 
+#pragma warning disable CS8605
 		private IEnumerable<(string FilePath, EFileType FileType)> RelatedFiles {
 			get {
-				foreach (EFileType? fileType in Enum.GetValues(typeof(EFileType))) {
-					if (fileType == null) {
-						continue;
-					}
-
-					string filePath = GetFilePath(fileType.Value);
+				foreach (EFileType fileType in Enum.GetValues(typeof(EFileType))) {
+					string filePath = GetFilePath(fileType);
 
 					if (string.IsNullOrEmpty(filePath)) {
 						ArchiLogger.LogNullError(nameof(filePath));
@@ -155,10 +152,11 @@ namespace ArchiSteamFarm {
 						yield break;
 					}
 
-					yield return (filePath, fileType.Value);
+					yield return (filePath, fileType);
 				}
 			}
 		}
+#pragma warning restore CS8605
 
 #pragma warning disable IDE0051
 		[JsonProperty(PropertyName = SharedInfo.UlongCompatibilityStringPrefix + nameof(SteamID))]
@@ -364,8 +362,8 @@ namespace ArchiSteamFarm {
 
 		[PublicAPI]
 		public static HashSet<Bot>? GetBots(string args) {
-			if (string.IsNullOrEmpty(args)) {
-				throw new ArgumentNullException(nameof(args));
+			if (string.IsNullOrEmpty(args) || (Bots == null)) {
+				throw new ArgumentNullException(nameof(args) + " || " + nameof(Bots));
 			}
 
 			string[] botNames = args.Split(new[] { ',' }, StringSplitOptions.RemoveEmptyEntries);
@@ -905,7 +903,7 @@ namespace ArchiSteamFarm {
 			string? gameName = null;
 
 			if (!string.IsNullOrEmpty(BotConfig.CustomGamePlayedWhileFarming)) {
-				gameName = string.Format(BotConfig.CustomGamePlayedWhileFarming, game.AppID, game.GameName);
+				gameName = string.Format(BotConfig.CustomGamePlayedWhileFarming!, game.AppID, game.GameName);
 			}
 
 			await ArchiHandler.PlayGames(game.PlayableAppID.ToEnumerable(), gameName).ConfigureAwait(false);
@@ -919,7 +917,7 @@ namespace ArchiSteamFarm {
 			string? gameName = null;
 
 			if (!string.IsNullOrEmpty(BotConfig.CustomGamePlayedWhileFarming)) {
-				gameName = string.Format(BotConfig.CustomGamePlayedWhileFarming, string.Join(", ", games.Select(game => game.AppID)), string.Join(", ", games.Select(game => game.GameName)));
+				gameName = string.Format(BotConfig.CustomGamePlayedWhileFarming!, string.Join(", ", games.Select(game => game.AppID)), string.Join(", ", games.Select(game => game.GameName)));
 			}
 
 			await ArchiHandler.PlayGames(games.Select(game => game.PlayableAppID), gameName).ConfigureAwait(false);
@@ -963,7 +961,7 @@ namespace ArchiSteamFarm {
 				if (gamesToRedeemInBackground.Count > 0) {
 					IOrderedDictionary validGamesToRedeemInBackground = ValidateGamesToRedeemInBackground(gamesToRedeemInBackground);
 
-					if ((validGamesToRedeemInBackground != null) && (validGamesToRedeemInBackground.Count > 0)) {
+					if (validGamesToRedeemInBackground.Count > 0) {
 						AddGamesToRedeemInBackground(validGamesToRedeemInBackground);
 					}
 				}
@@ -1249,7 +1247,7 @@ namespace ArchiSteamFarm {
 
 			ArchiLogger.LogChatMessage(true, message, steamID: steamID);
 
-			string? steamMessagePrefix = ASF.GlobalConfig?.SteamMessagePrefix ?? GlobalConfig.DefaultSteamMessagePrefix;
+			string? steamMessagePrefix = ASF.GlobalConfig != null ? ASF.GlobalConfig.SteamMessagePrefix : GlobalConfig.DefaultSteamMessagePrefix;
 			ushort maxMessageLength = (ushort) (MaxMessageLength - ReservedMessageLength - (steamMessagePrefix?.Length ?? 0));
 
 			// We must escape our message prior to sending it
@@ -1344,7 +1342,7 @@ namespace ArchiSteamFarm {
 
 			ArchiLogger.LogChatMessage(true, message, chatGroupID, chatID);
 
-			string? steamMessagePrefix = ASF.GlobalConfig?.SteamMessagePrefix ?? GlobalConfig.DefaultSteamMessagePrefix;
+			string? steamMessagePrefix = ASF.GlobalConfig != null ? ASF.GlobalConfig.SteamMessagePrefix : GlobalConfig.DefaultSteamMessagePrefix;
 			ushort maxMessageLength = (ushort) (MaxMessageLength - ReservedMessageLength - (steamMessagePrefix?.Length ?? 0));
 
 			// We must escape our message prior to sending it
@@ -1492,6 +1490,7 @@ namespace ArchiSteamFarm {
 			}
 		}
 
+#pragma warning disable CS8605
 		internal static IOrderedDictionary ValidateGamesToRedeemInBackground(IOrderedDictionary gamesToRedeemInBackground) {
 			if ((gamesToRedeemInBackground == null) || (gamesToRedeemInBackground.Count == 0)) {
 				throw new ArgumentNullException(nameof(gamesToRedeemInBackground));
@@ -1499,10 +1498,10 @@ namespace ArchiSteamFarm {
 
 			HashSet<object> invalidKeys = new HashSet<object>();
 
-			foreach (DictionaryEntry? game in gamesToRedeemInBackground) {
+			foreach (DictionaryEntry game in gamesToRedeemInBackground) {
 				bool invalid = false;
 
-				string? key = game?.Key as string;
+				string? key = game.Key as string;
 
 				if (string.IsNullOrEmpty(key)) {
 					invalid = true;
@@ -1512,7 +1511,7 @@ namespace ArchiSteamFarm {
 					ASF.ArchiLogger.LogGenericWarning(string.Format(Strings.ErrorIsInvalid, key));
 				}
 
-				string? name = game?.Value as string;
+				string? name = game.Value as string;
 
 				if (string.IsNullOrEmpty(name)) {
 					invalid = true;
@@ -1532,6 +1531,7 @@ namespace ArchiSteamFarm {
 
 			return gamesToRedeemInBackground;
 		}
+#pragma warning restore CS8605
 
 		private async Task CheckOccupationStatus() {
 			StopPlayingWasBlockedTimer();
@@ -1730,8 +1730,9 @@ namespace ArchiSteamFarm {
 					return;
 				}
 
-				MobileAuthenticator authenticator = JsonConvert.DeserializeObject<MobileAuthenticator>(json);
+				MobileAuthenticator? authenticator = JsonConvert.DeserializeObject<MobileAuthenticator>(json);
 
+				// ReSharper disable once ConditionIsAlwaysTrueOrFalse - wrong, "null" json serializes into null object
 				if (authenticator == null) {
 					ArchiLogger.LogNullError(nameof(authenticator));
 
@@ -1962,9 +1963,7 @@ namespace ArchiSteamFarm {
 
 		private async void OnConnected(SteamClient.ConnectedCallback callback) {
 			if (callback == null) {
-				ArchiLogger.LogNullError(nameof(callback));
-
-				return;
+				throw new ArgumentNullException(nameof(callback));
 			}
 
 			HeartBeatFailures = 0;
@@ -2028,14 +2027,18 @@ namespace ArchiSteamFarm {
 				return;
 			}
 
+			if (string.IsNullOrEmpty(BotConfig.SteamLogin)) {
+				throw new ArgumentNullException(nameof(BotConfig.SteamLogin));
+			}
+
 			// Steam login and password fields can contain ASCII characters only, including spaces
 			const string nonAsciiPattern = @"[^\u0000-\u007F]+";
 
-			string username = Regex.Replace(BotConfig.SteamLogin, nonAsciiPattern, "", RegexOptions.CultureInvariant | RegexOptions.IgnoreCase);
+			string username = Regex.Replace(BotConfig.SteamLogin!, nonAsciiPattern, "", RegexOptions.CultureInvariant | RegexOptions.IgnoreCase);
 			string? password = BotConfig.DecryptedSteamPassword;
 
 			if (!string.IsNullOrEmpty(password)) {
-				password = Regex.Replace(password, nonAsciiPattern, "", RegexOptions.CultureInvariant | RegexOptions.IgnoreCase);
+				password = Regex.Replace(password!, nonAsciiPattern, "", RegexOptions.CultureInvariant | RegexOptions.IgnoreCase);
 			}
 
 			ArchiLogger.LogGenericInfo(Strings.BotLoggingIn);
@@ -2067,16 +2070,8 @@ namespace ArchiSteamFarm {
 		}
 
 		private async void OnDisconnected(SteamClient.DisconnectedCallback callback) {
-			if (ASF.LoginRateLimitingSemaphore == null) {
-				ASF.ArchiLogger.LogNullError(nameof(ASF.LoginRateLimitingSemaphore));
-
-				return;
-			}
-
-			if (callback == null) {
-				ArchiLogger.LogNullError(nameof(callback));
-
-				return;
+			if ((callback == null) || (ASF.LoginRateLimitingSemaphore == null)) {
+				throw new ArgumentNullException(nameof(callback) + " || " + nameof(ASF.LoginRateLimitingSemaphore));
 			}
 
 			EResult lastLogOnResult = LastLogOnResult;
@@ -2147,10 +2142,12 @@ namespace ArchiSteamFarm {
 		}
 
 		private async void OnFriendsList(SteamFriends.FriendsListCallback callback) {
-			if (callback?.FriendList == null) {
-				ArchiLogger.LogNullError(nameof(callback) + " || " + nameof(callback.FriendList));
+			if (callback == null) {
+				throw new ArgumentNullException(nameof(callback));
+			}
 
-				return;
+			if (callback.FriendList == null) {
+				throw new ArgumentNullException(nameof(callback.FriendList));
 			}
 
 			foreach (SteamFriends.FriendsListCallback.Friend friend in callback.FriendList.Where(friend => friend.Relationship == EFriendRelationship.RequestRecipient)) {
@@ -2206,10 +2203,12 @@ namespace ArchiSteamFarm {
 		}
 
 		private async void OnGuestPassList(SteamApps.GuestPassListCallback callback) {
-			if (callback?.GuestPasses == null) {
-				ArchiLogger.LogNullError(nameof(callback) + " || " + nameof(callback.GuestPasses));
+			if (callback == null) {
+				throw new ArgumentNullException(nameof(callback));
+			}
 
-				return;
+			if (callback.GuestPasses == null) {
+				throw new ArgumentNullException(nameof(callback.GuestPasses));
 			}
 
 			if ((callback.CountGuestPassesToRedeem == 0) || (callback.GuestPasses.Count == 0) || !BotConfig.AcceptGifts) {
@@ -2227,9 +2226,7 @@ namespace ArchiSteamFarm {
 
 		private async Task OnIncomingChatMessage(CChatRoom_IncomingChatMessage_Notification notification) {
 			if (notification == null) {
-				ArchiLogger.LogNullError(nameof(notification));
-
-				return;
+				throw new ArgumentNullException(nameof(notification));
 			}
 
 			// Under normal circumstances, timestamp must always be greater than 0, but Steam already proved that it's capable of going against the logic
@@ -2265,9 +2262,7 @@ namespace ArchiSteamFarm {
 
 		private async Task OnIncomingMessage(CFriendMessages_IncomingMessage_Notification notification) {
 			if (notification == null) {
-				ArchiLogger.LogNullError(nameof(notification));
-
-				return;
+				throw new ArgumentNullException(nameof(notification));
 			}
 
 			if ((EChatEntryType) notification.chat_entry_type != EChatEntryType.ChatMsg) {
@@ -2306,14 +2301,16 @@ namespace ArchiSteamFarm {
 		}
 
 		private async void OnLicenseList(SteamApps.LicenseListCallback callback) {
-			if (ASF.GlobalDatabase == null) {
-				throw new ArgumentNullException(nameof(ASF.GlobalDatabase));
+			if (callback == null) {
+				throw new ArgumentNullException(nameof(callback));
 			}
 
-			if (callback?.LicenseList == null) {
-				ArchiLogger.LogNullError(nameof(callback) + " || " + nameof(callback.LicenseList));
+			if (callback.LicenseList == null) {
+				throw new ArgumentNullException(nameof(callback.LicenseList));
+			}
 
-				return;
+			if (ASF.GlobalDatabase == null) {
+				throw new ArgumentNullException(nameof(ASF.GlobalDatabase));
 			}
 
 			if (callback.LicenseList.Count == 0) {
@@ -2359,9 +2356,7 @@ namespace ArchiSteamFarm {
 
 		private void OnLoggedOff(SteamUser.LoggedOffCallback callback) {
 			if (callback == null) {
-				ArchiLogger.LogNullError(nameof(callback));
-
-				return;
+				throw new ArgumentNullException(nameof(callback));
 			}
 
 			LastLogOnResult = callback.Result;
@@ -2395,9 +2390,7 @@ namespace ArchiSteamFarm {
 
 		private async void OnLoggedOn(SteamUser.LoggedOnCallback callback) {
 			if (callback == null) {
-				ArchiLogger.LogNullError(nameof(callback));
-
-				return;
+				throw new ArgumentNullException(nameof(callback));
 			}
 
 			// Always reset one-time-only access tokens when we get OnLoggedOn() response
@@ -2613,17 +2606,19 @@ namespace ArchiSteamFarm {
 		}
 
 		private void OnLoginKey(SteamUser.LoginKeyCallback callback) {
-			if (string.IsNullOrEmpty(callback?.LoginKey)) {
-				ArchiLogger.LogNullError(nameof(callback) + " || " + nameof(callback.LoginKey));
+			if (callback == null) {
+				throw new ArgumentNullException(nameof(callback));
+			}
 
-				return;
+			if (string.IsNullOrEmpty(callback.LoginKey)) {
+				throw new ArgumentNullException(nameof(callback.LoginKey));
 			}
 
 			if (!BotConfig.UseLoginKeys) {
 				return;
 			}
 
-			string? loginKey = callback!.LoginKey;
+			string? loginKey = callback.LoginKey;
 
 			if (BotConfig.PasswordFormat != ArchiCryptoHelper.ECryptoMethod.PlainText) {
 				loginKey = ArchiCryptoHelper.Encrypt(BotConfig.PasswordFormat, loginKey);
@@ -2635,9 +2630,7 @@ namespace ArchiSteamFarm {
 
 		private async void OnMachineAuth(SteamUser.UpdateMachineAuthCallback callback) {
 			if (callback == null) {
-				ArchiLogger.LogNullError(nameof(callback));
-
-				return;
+				throw new ArgumentNullException(nameof(callback));
 			}
 
 			string sentryFilePath = GetFilePath(EFileType.SentryFile);
@@ -2698,9 +2691,7 @@ namespace ArchiSteamFarm {
 
 		private void OnPersonaState(SteamFriends.PersonaStateCallback callback) {
 			if (callback == null) {
-				ArchiLogger.LogNullError(nameof(callback));
-
-				return;
+				throw new ArgumentNullException(nameof(callback));
 			}
 
 			if (callback.FriendID != SteamID) {
@@ -2727,9 +2718,7 @@ namespace ArchiSteamFarm {
 
 		private async void OnPlayingSessionState(ArchiHandler.PlayingSessionStateCallback callback) {
 			if (callback == null) {
-				ArchiLogger.LogNullError(nameof(callback));
-
-				return;
+				throw new ArgumentNullException(nameof(callback));
 			}
 
 			if (callback.PlayingBlocked == PlayingBlocked) {
@@ -2742,9 +2731,7 @@ namespace ArchiSteamFarm {
 
 		private async void OnServiceMethod(SteamUnifiedMessages.ServiceMethodNotification notification) {
 			if (notification == null) {
-				ArchiLogger.LogNullError(nameof(notification));
-
-				return;
+				throw new ArgumentNullException(nameof(notification));
 			}
 
 			switch (notification.MethodName) {
@@ -2761,9 +2748,7 @@ namespace ArchiSteamFarm {
 
 		private async void OnSharedLibraryLockStatus(ArchiHandler.SharedLibraryLockStatusCallback callback) {
 			if (callback == null) {
-				ArchiLogger.LogNullError(nameof(callback));
-
-				return;
+				throw new ArgumentNullException(nameof(callback));
 			}
 
 			// Ignore no status updates
@@ -2786,12 +2771,14 @@ namespace ArchiSteamFarm {
 
 		private void OnUserNotifications(ArchiHandler.UserNotificationsCallback callback) {
 			if (callback == null) {
-				ArchiLogger.LogNullError(nameof(callback));
-
-				return;
+				throw new ArgumentNullException(nameof(callback));
 			}
 
-			if ((callback.Notifications == null) || (callback.Notifications.Count == 0)) {
+			if (callback.Notifications == null) {
+				throw new ArgumentNullException(nameof(callback));
+			}
+
+			if (callback.Notifications.Count == 0) {
 				return;
 			}
 
@@ -2841,9 +2828,7 @@ namespace ArchiSteamFarm {
 
 		private void OnVanityURLChangedCallback(ArchiHandler.VanityURLChangedCallback callback) {
 			if (callback == null) {
-				ArchiLogger.LogNullError(nameof(callback));
-
-				return;
+				throw new ArgumentNullException(nameof(callback));
 			}
 
 			ArchiWebHandler.OnVanityURLChanged(callback.VanityURL);
@@ -2851,9 +2836,7 @@ namespace ArchiSteamFarm {
 
 		private void OnWalletUpdate(SteamUser.WalletInfoCallback callback) {
 			if (callback == null) {
-				ArchiLogger.LogNullError(nameof(callback));
-
-				return;
+				throw new ArgumentNullException(nameof(callback));
 			}
 
 			WalletBalance = callback.LongBalance;

ArchiSteamFarm/BotConfig.cs

@@ -333,6 +333,7 @@ namespace ArchiSteamFarm {
 				return null;
 			}
 
+			// ReSharper disable once ConditionIsAlwaysTrueOrFalse - wrong, "null" json serializes into null object
 			if (botConfig == null) {
 				ASF.ArchiLogger.LogNullError(nameof(botConfig));
 

ArchiSteamFarm/BotDatabase.cs

@@ -182,6 +182,7 @@ namespace ArchiSteamFarm {
 				return null;
 			}
 
+			// ReSharper disable once ConditionIsAlwaysTrueOrFalse - wrong, "null" json serializes into null object
 			if (botDatabase == null) {
 				ASF.ArchiLogger.LogNullError(nameof(botDatabase));
 
@@ -195,15 +196,17 @@ namespace ArchiSteamFarm {
 
 		internal IReadOnlyCollection<ulong> GetBlacklistedFromTradesSteamIDs() => BlacklistedFromTradesSteamIDs;
 
+#pragma warning disable CS8605
 		internal (string? Key, string? Name) GetGameToRedeemInBackground() {
 			lock (GamesToRedeemInBackground) {
-				foreach (DictionaryEntry? game in GamesToRedeemInBackground) {
-					return (game?.Key as string, game?.Value as string);
+				foreach (DictionaryEntry game in GamesToRedeemInBackground) {
+					return (game.Key as string, game.Value as string);
 				}
 			}
 
 			return (null, null);
 		}
+#pragma warning restore CS8605
 
 		internal IReadOnlyCollection<uint> GetIdlingBlacklistedAppIDs() => IdlingBlacklistedAppIDs;
 		internal IReadOnlyCollection<uint> GetIdlingPriorityAppIDs() => IdlingPriorityAppIDs;

ArchiSteamFarm/CMsgs/CMsgClientAcknowledgeClanInvite.cs

@@ -19,6 +19,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+using System;
 using System.IO;
 using System.Text;
 using SteamKit2;
@@ -31,9 +32,7 @@ namespace ArchiSteamFarm.CMsgs {
 
 		void ISteamSerializable.Deserialize(Stream stream) {
 			if (stream == null) {
-				ASF.ArchiLogger.LogNullError(nameof(stream));
-
-				return;
+				throw new ArgumentNullException(nameof(stream));
 			}
 
 			using BinaryReader binaryReader = new BinaryReader(stream, Encoding.UTF8, true);
@@ -46,9 +45,7 @@ namespace ArchiSteamFarm.CMsgs {
 
 		void ISteamSerializable.Serialize(Stream stream) {
 			if (stream == null) {
-				ASF.ArchiLogger.LogNullError(nameof(stream));
-
-				return;
+				throw new ArgumentNullException(nameof(stream));
 			}
 
 			using BinaryWriter binaryWriter = new BinaryWriter(stream, Encoding.UTF8, true);

ArchiSteamFarm/Commands.cs

@@ -289,10 +289,10 @@ namespace ArchiSteamFarm {
 				throw new ArgumentNullException(nameof(steamID) + " || " + nameof(message));
 			}
 
-			string commandPrefix = ASF.GlobalConfig?.CommandPrefix ?? GlobalConfig.DefaultCommandPrefix;
+			string? commandPrefix = ASF.GlobalConfig != null ? ASF.GlobalConfig.CommandPrefix : GlobalConfig.DefaultCommandPrefix;
 
 			if (!string.IsNullOrEmpty(commandPrefix)) {
-				if (!message.StartsWith(commandPrefix, StringComparison.OrdinalIgnoreCase)) {
+				if (!message.StartsWith(commandPrefix!, StringComparison.OrdinalIgnoreCase)) {
 					string? pluginsResponse = await PluginsCore.OnBotMessage(Bot, steamID, message).ConfigureAwait(false);
 
 					if (!string.IsNullOrEmpty(pluginsResponse)) {
@@ -305,7 +305,7 @@ namespace ArchiSteamFarm {
 					return;
 				}
 
-				message = message.Substring(commandPrefix.Length);
+				message = message.Substring(commandPrefix!.Length);
 			}
 
 			Task<string?> responseTask = Response(steamID, message);
@@ -346,10 +346,10 @@ namespace ArchiSteamFarm {
 				throw new ArgumentNullException(nameof(chatGroupID) + " || " + nameof(chatID) + " || " + nameof(steamID) + " || " + nameof(message));
 			}
 
-			string commandPrefix = ASF.GlobalConfig?.CommandPrefix ?? GlobalConfig.DefaultCommandPrefix;
+			string? commandPrefix = ASF.GlobalConfig != null ? ASF.GlobalConfig.CommandPrefix : GlobalConfig.DefaultCommandPrefix;
 
 			if (!string.IsNullOrEmpty(commandPrefix)) {
-				if (!message.StartsWith(commandPrefix, StringComparison.OrdinalIgnoreCase)) {
+				if (!message.StartsWith(commandPrefix!, StringComparison.OrdinalIgnoreCase)) {
 					string? pluginsResponse = await PluginsCore.OnBotMessage(Bot, steamID, message).ConfigureAwait(false);
 
 					if (!string.IsNullOrEmpty(pluginsResponse)) {
@@ -362,7 +362,7 @@ namespace ArchiSteamFarm {
 					return;
 				}
 
-				message = message.Substring(commandPrefix.Length);
+				message = message.Substring(commandPrefix!.Length);
 			}
 
 			Task<string?> responseTask = Response(steamID, message);
@@ -1680,7 +1680,7 @@ namespace ArchiSteamFarm {
 
 			Dictionary<string, (ushort Count, string GameName)> ownedGamesStats = new Dictionary<string, (ushort Count, string GameName)>();
 
-			foreach ((string gameID, string gameName) in validResults.Where(validResult => (validResult.OwnedGames != null) && (validResult.OwnedGames.Count > 0)).SelectMany(validResult => validResult.OwnedGames)) {
+			foreach ((string gameID, string gameName) in validResults.Where(validResult => validResult.OwnedGames.Count > 0).SelectMany(validResult => validResult.OwnedGames)) {
 				if (ownedGamesStats.TryGetValue(gameID, out (ushort Count, string GameName) ownedGameStats)) {
 					ownedGameStats.Count++;
 				} else {
@@ -2003,8 +2003,8 @@ namespace ArchiSteamFarm {
 		}
 
 		private async Task<string?> ResponseRedeem(ulong steamID, string keysText, ERedeemFlags redeemFlags = ERedeemFlags.None) {
-			if ((steamID == 0) || !new SteamID(steamID).IsIndividualAccount || string.IsNullOrEmpty(keysText)) {
-				throw new ArgumentNullException(nameof(steamID) + " || " + nameof(keysText));
+			if ((steamID == 0) || !new SteamID(steamID).IsIndividualAccount || string.IsNullOrEmpty(keysText) || (Bot.Bots == null)) {
+				throw new ArgumentNullException(nameof(steamID) + " || " + nameof(keysText) + " || " + nameof(Bot.Bots));
 			}
 
 			if (!Bot.HasPermission(steamID, BotConfig.EPermission.Operator)) {

ArchiSteamFarm/GitHub.cs

@@ -53,7 +53,7 @@ namespace ArchiSteamFarm {
 			return await GetReleaseFromURL(SharedInfo.GithubReleaseURL + "/tags/" + version).ConfigureAwait(false);
 		}
 
-		private static MarkdownDocument? ExtractChangelogFromBody(string markdownText) {
+		private static MarkdownDocument ExtractChangelogFromBody(string markdownText) {
 			if (string.IsNullOrEmpty(markdownText)) {
 				throw new ArgumentNullException(nameof(markdownText));
 			}

ArchiSteamFarm/GlobalConfig.cs

@@ -158,7 +158,7 @@ namespace ArchiSteamFarm {
 				Uri uri;
 
 				try {
-					uri = new Uri(WebProxyText);
+					uri = new Uri(WebProxyText!);
 				} catch (UriFormatException e) {
 					ASF.ArchiLogger.LogGenericException(e);
 
@@ -299,6 +299,7 @@ namespace ArchiSteamFarm {
 				return null;
 			}
 
+			// ReSharper disable once ConditionIsAlwaysTrueOrFalse - wrong, "null" json serializes into null object
 			if (globalConfig == null) {
 				ASF.ArchiLogger.LogNullError(nameof(globalConfig));
 

ArchiSteamFarm/GlobalDatabase.cs

@@ -122,6 +122,7 @@ namespace ArchiSteamFarm {
 				return null;
 			}
 
+			// ReSharper disable once ConditionIsAlwaysTrueOrFalse - wrong, "null" json serializes into null object
 			if (globalDatabase == null) {
 				ASF.ArchiLogger.LogNullError(nameof(globalDatabase));
 

ArchiSteamFarm/Helpers/CrossProcessFileBasedSemaphore.cs

@@ -159,15 +159,15 @@ namespace ArchiSteamFarm.Helpers {
 			}
 
 			if (!Directory.Exists(directoryPath)) {
-				Directory.CreateDirectory(directoryPath);
+				Directory.CreateDirectory(directoryPath!);
 
 				if (OS.IsUnix) {
-					OS.UnixSetFileAccess(directoryPath, OS.EUnixPermission.Combined777);
+					OS.UnixSetFileAccess(directoryPath!, OS.EUnixPermission.Combined777);
 				} else {
-					DirectoryInfo directoryInfo = new DirectoryInfo(directoryPath);
+					DirectoryInfo directoryInfo = new DirectoryInfo(directoryPath!);
 
 					try {
-						DirectorySecurity directorySecurity = new DirectorySecurity(directoryPath, AccessControlSections.All);
+						DirectorySecurity directorySecurity = new DirectorySecurity(directoryPath!, AccessControlSections.All);
 
 						directoryInfo.SetAccessControl(directorySecurity);
 					} catch (PrivilegeNotHeldException e) {

ArchiSteamFarm/Helpers/SerializableFile.cs

@@ -78,9 +78,9 @@ namespace ArchiSteamFarm.Helpers {
 				await RuntimeCompatibility.File.WriteAllTextAsync(newFilePath, json).ConfigureAwait(false);
 
 				if (File.Exists(FilePath)) {
-					File.Replace(newFilePath, FilePath, null);
+					File.Replace(newFilePath, FilePath!, null);
 				} else {
-					File.Move(newFilePath, FilePath);
+					File.Move(newFilePath, FilePath!);
 				}
 			} catch (Exception e) {
 				ASF.ArchiLogger.LogGenericException(e);

ArchiSteamFarm/IPC/ArchiKestrel.cs

@@ -31,9 +31,9 @@ using Microsoft.Extensions.Logging;
 using Newtonsoft.Json;
 using Newtonsoft.Json.Linq;
 using NLog.Web;
+
 #if !NETFRAMEWORK
 using Microsoft.Extensions.Hosting;
-
 #endif
 
 namespace ArchiSteamFarm.IPC {

ArchiSteamFarm/IPC/Controllers/Api/BotController.cs

@@ -220,7 +220,7 @@ namespace ArchiSteamFarm.IPC.Controllers.Api {
 
 			IOrderedDictionary validGamesToRedeemInBackground = Bot.ValidateGamesToRedeemInBackground(request.GamesToRedeemInBackground);
 
-			if ((validGamesToRedeemInBackground == null) || (validGamesToRedeemInBackground.Count == 0)) {
+			if (validGamesToRedeemInBackground.Count == 0) {
 				return BadRequest(new GenericResponse(false, string.Format(Strings.ErrorIsEmpty, nameof(validGamesToRedeemInBackground))));
 			}
 

ArchiSteamFarm/IPC/Controllers/Api/CommandController.cs

@@ -57,16 +57,16 @@ namespace ArchiSteamFarm.IPC.Controllers.Api {
 				return BadRequest(new GenericResponse(false, string.Format(Strings.ErrorIsInvalid, nameof(ASF.GlobalConfig.SteamOwnerID))));
 			}
 
-			Bot? targetBot = Bot.Bots.OrderBy(bot => bot.Key, Bot.BotsComparer).Select(bot => bot.Value).FirstOrDefault();
+			Bot? targetBot = Bot.Bots?.OrderBy(bot => bot.Key, Bot.BotsComparer).Select(bot => bot.Value).FirstOrDefault();
 
 			if (targetBot == null) {
 				return BadRequest(new GenericResponse(false, Strings.ErrorNoBotsDefined));
 			}
 
 			string command = request.Command!;
-			string? commandPrefix = ASF.GlobalConfig?.CommandPrefix ?? GlobalConfig.DefaultCommandPrefix;
+			string? commandPrefix = ASF.GlobalConfig != null ? ASF.GlobalConfig.CommandPrefix : GlobalConfig.DefaultCommandPrefix;
 
-			if (!string.IsNullOrEmpty(commandPrefix) && command.StartsWith(commandPrefix, StringComparison.Ordinal)) {
+			if (!string.IsNullOrEmpty(commandPrefix) && command.StartsWith(commandPrefix!, StringComparison.Ordinal)) {
 				command = command.Substring(commandPrefix!.Length);
 
 				if (string.IsNullOrEmpty(command)) {

ArchiSteamFarm/IPC/Controllers/Api/TypeController.cs

@@ -87,11 +87,7 @@ namespace ArchiSteamFarm.IPC.Controllers.Api {
 				underlyingType = enumType.GetUnifiedName();
 
 				foreach (object? value in Enum.GetValues(targetType)) {
-					if (value == null) {
-						continue;
-					}
-
-					string? valueText = value.ToString();
+					string? valueText = value?.ToString();
 
 					if (string.IsNullOrEmpty(valueText)) {
 						ASF.ArchiLogger.LogNullError(nameof(valueText));
@@ -105,7 +101,7 @@ namespace ArchiSteamFarm.IPC.Controllers.Api {
 						continue;
 					}
 
-					body[valueText] = valueObjText!;
+					body[valueText!] = valueObjText!;
 				}
 			}
 

ArchiSteamFarm/IPC/Integration/ApiAuthenticationMiddleware.cs

@@ -80,7 +80,7 @@ namespace ArchiSteamFarm.IPC.Integration {
 				throw new ArgumentNullException(nameof(context) + " || " + nameof(ClearFailedAuthorizationsTimer));
 			}
 
-			string? ipcPassword = ASF.GlobalConfig?.IPCPassword ?? GlobalConfig.DefaultIPCPassword;
+			string? ipcPassword = ASF.GlobalConfig != null ? ASF.GlobalConfig.IPCPassword : GlobalConfig.DefaultIPCPassword;
 
 			if (string.IsNullOrEmpty(ipcPassword)) {
 				return HttpStatusCode.OK;

ArchiSteamFarm/IPC/Integration/EnumSchemaFilter.cs

@@ -31,9 +31,7 @@ namespace ArchiSteamFarm.IPC.Integration {
 	internal sealed class EnumSchemaFilter : ISchemaFilter {
 		public void Apply(OpenApiSchema schema, SchemaFilterContext context) {
 			if ((schema == null) || (context == null)) {
-				ASF.ArchiLogger.LogNullError(nameof(schema) + " || " + nameof(context));
-
-				return;
+				throw new ArgumentNullException(nameof(schema) + " || " + nameof(context));
 			}
 
 			if (!context.Type.IsEnum) {
@@ -74,7 +72,7 @@ namespace ArchiSteamFarm.IPC.Integration {
 					throw new ArgumentOutOfRangeException(nameof(enumValue));
 				}
 
-				definition.Add(enumName, enumObject);
+				definition.Add(enumName!, enumObject);
 			}
 
 			schema.AddExtension("x-definition", definition);

ArchiSteamFarm/IPC/Requests/TwoFactorAuthenticationConfirmationsRequest.cs

@@ -19,6 +19,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+using System;
 using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.Diagnostics.CodeAnalysis;
@@ -59,9 +60,7 @@ namespace ArchiSteamFarm.IPC.Requests {
 		public ImmutableHashSet<string> SAcceptedCreatorIDs {
 			set {
 				if (value == null) {
-					ASF.ArchiLogger.LogNullError(nameof(value));
-
-					return;
+					throw new ArgumentNullException(nameof(value));
 				}
 
 				HashSet<ulong> acceptedCreatorIDs = new HashSet<ulong>(value.Count);

ArchiSteamFarm/IPC/Startup.cs

@@ -39,7 +39,6 @@ using Newtonsoft.Json.Serialization;
 
 #if NETFRAMEWORK
 using Newtonsoft.Json.Converters;
-
 #endif
 
 namespace ArchiSteamFarm.IPC {
@@ -92,7 +91,7 @@ namespace ArchiSteamFarm.IPC {
 			app.UseRouting();
 #endif
 
-			string? ipcPassword = ASF.GlobalConfig?.IPCPassword ?? GlobalConfig.DefaultIPCPassword;
+			string? ipcPassword = ASF.GlobalConfig != null ? ASF.GlobalConfig.IPCPassword : GlobalConfig.DefaultIPCPassword;
 
 			if (!string.IsNullOrEmpty(ipcPassword)) {
 				// We need ApiAuthenticationMiddleware for IPCPassword
@@ -137,7 +136,7 @@ namespace ArchiSteamFarm.IPC {
 			// Add support for response compression
 			services.AddResponseCompression();
 
-			string? ipcPassword = ASF.GlobalConfig?.IPCPassword ?? GlobalConfig.DefaultIPCPassword;
+			string? ipcPassword = ASF.GlobalConfig != null ? ASF.GlobalConfig.IPCPassword : GlobalConfig.DefaultIPCPassword;
 
 			// Add CORS to allow userscripts and third-party apps
 			if (!string.IsNullOrEmpty(ipcPassword)) {

ArchiSteamFarm/Json/Steam.cs

@@ -335,9 +335,7 @@ namespace ArchiSteamFarm.Json {
 			[PublicAPI]
 			public bool IsValidSteamItemsRequest(IReadOnlyCollection<Asset.EType> acceptedTypes) {
 				if ((acceptedTypes == null) || (acceptedTypes.Count == 0)) {
-					ASF.ArchiLogger.LogNullError(nameof(acceptedTypes));
-
-					return false;
+					throw new ArgumentNullException(nameof(acceptedTypes));
 				}
 
 				return ItemsToGive.All(item => (item.AppID == Asset.SteamAppID) && (item.ContextID == Asset.SteamCommunityContextID) && acceptedTypes.Contains(item.Type));

ArchiSteamFarm/MobileAuthenticator.cs

@@ -257,7 +257,7 @@ namespace ArchiSteamFarm {
 			byte[] identitySecret;
 
 			try {
-				identitySecret = Convert.FromBase64String(IdentitySecret);
+				identitySecret = Convert.FromBase64String(IdentitySecret!);
 			} catch (FormatException e) {
 				Bot.ArchiLogger.LogGenericException(e);
 				Bot.ArchiLogger.LogGenericError(string.Format(Strings.ErrorIsInvalid, nameof(IdentitySecret)));
@@ -282,7 +282,7 @@ namespace ArchiSteamFarm {
 			Array.Copy(timeArray, buffer, 8);
 
 			if (!string.IsNullOrEmpty(tag)) {
-				Array.Copy(Encoding.UTF8.GetBytes(tag), 0, buffer, 8, bufferSize - 8);
+				Array.Copy(Encoding.UTF8.GetBytes(tag!), 0, buffer, 8, bufferSize - 8);
 			}
 
 			using HMACSHA1 hmac = new HMACSHA1(identitySecret);
@@ -300,7 +300,7 @@ namespace ArchiSteamFarm {
 			byte[] sharedSecret;
 
 			try {
-				sharedSecret = Convert.FromBase64String(SharedSecret);
+				sharedSecret = Convert.FromBase64String(SharedSecret!);
 			} catch (FormatException e) {
 				Bot.ArchiLogger.LogGenericException(e);
 				Bot.ArchiLogger.LogGenericError(string.Format(Strings.ErrorIsInvalid, nameof(SharedSecret)));

ArchiSteamFarm/NLog/HistoryTarget.cs

@@ -62,9 +62,7 @@ namespace ArchiSteamFarm.NLog {
 
 		protected override void Write(LogEventInfo logEvent) {
 			if (logEvent == null) {
-				ASF.ArchiLogger.LogNullError(nameof(logEvent));
-
-				return;
+				throw new ArgumentNullException(nameof(logEvent));
 			}
 
 			base.Write(logEvent);

ArchiSteamFarm/NLog/Logging.cs

@@ -76,7 +76,7 @@ namespace ArchiSteamFarm.NLog {
 
 			await ConsoleSemaphore.WaitAsync().ConfigureAwait(false);
 
-			string result;
+			string? result;
 
 			try {
 				OnUserInputStart();
@@ -131,7 +131,7 @@ namespace ArchiSteamFarm.NLog {
 				ConsoleSemaphore.Release();
 			}
 
-			return !string.IsNullOrEmpty(result) ? result.Trim() : null;
+			return !string.IsNullOrEmpty(result) ? result!.Trim() : null;
 		}
 
 		internal static void InitCoreLoggers(bool uniqueInstance) {
@@ -221,7 +221,7 @@ namespace ArchiSteamFarm.NLog {
 			ASF.ArchiLogger.LogGenericInfo(Strings.InteractiveConsoleEnabled);
 		}
 
-		private static string ConsoleReadLine() {
+		private static string? ConsoleReadLine() {
 			Console.Beep();
 
 			return Console.ReadLine();
@@ -277,23 +277,23 @@ namespace ArchiSteamFarm.NLog {
 
 						try {
 							Console.Write(@">> " + Strings.EnterCommand);
-							string command = ConsoleReadLine();
+							string? command = ConsoleReadLine();
 
 							if (string.IsNullOrEmpty(command)) {
 								continue;
 							}
 
-							string commandPrefix = ASF.GlobalConfig?.CommandPrefix ?? GlobalConfig.DefaultCommandPrefix;
+							string? commandPrefix = ASF.GlobalConfig != null ? ASF.GlobalConfig.CommandPrefix : GlobalConfig.DefaultCommandPrefix;
 
-							if (!string.IsNullOrEmpty(commandPrefix) && command.StartsWith(commandPrefix, StringComparison.Ordinal)) {
-								command = command.Substring(commandPrefix.Length);
+							if (!string.IsNullOrEmpty(commandPrefix) && command!.StartsWith(commandPrefix!, StringComparison.Ordinal)) {
+								command = command.Substring(commandPrefix!.Length);
 
 								if (string.IsNullOrEmpty(command)) {
 									continue;
 								}
 							}
 
-							Bot? targetBot = Bot.Bots.OrderBy(bot => bot.Key, Bot.BotsComparer).Select(bot => bot.Value).FirstOrDefault();
+							Bot? targetBot = Bot.Bots?.OrderBy(bot => bot.Key, Bot.BotsComparer).Select(bot => bot.Value).FirstOrDefault();
 
 							if (targetBot == null) {
 								Console.WriteLine(@"<< " + Strings.ErrorNoBotsDefined);
@@ -305,7 +305,7 @@ namespace ArchiSteamFarm.NLog {
 
 							ulong steamOwnerID = ASF.GlobalConfig?.SteamOwnerID ?? GlobalConfig.DefaultSteamOwnerID;
 
-							string? response = await targetBot.Commands.Response(steamOwnerID, command).ConfigureAwait(false);
+							string? response = await targetBot.Commands.Response(steamOwnerID, command!).ConfigureAwait(false);
 
 							if (string.IsNullOrEmpty(response)) {
 								ASF.ArchiLogger.LogNullError(nameof(response));
@@ -341,9 +341,7 @@ namespace ArchiSteamFarm.NLog {
 
 		private static void OnConfigurationChanged(object? sender, LoggingConfigurationChangedEventArgs e) {
 			if (e == null) {
-				ASF.ArchiLogger.LogNullError(nameof(e));
-
-				return;
+				throw new ArgumentNullException(nameof(e));
 			}
 
 			InitConsoleLoggers();

ArchiSteamFarm/NLog/SteamTarget.cs

@@ -55,9 +55,7 @@ namespace ArchiSteamFarm.NLog {
 
 		protected override async void Write(LogEventInfo logEvent) {
 			if (logEvent == null) {
-				ASF.ArchiLogger.LogNullError(nameof(logEvent));
-
-				return;
+				throw new ArgumentNullException(nameof(logEvent));
 			}
 
 			base.Write(logEvent);

ArchiSteamFarm/Plugins/PluginsCore.cs

@@ -36,15 +36,13 @@ using SteamKit2;
 
 namespace ArchiSteamFarm.Plugins {
 	internal static class PluginsCore {
-		internal static bool HasCustomPluginsLoaded => HasActivePluginsLoaded && ActivePlugins.Any(plugin => !(plugin is OfficialPlugin officialPlugin) || !officialPlugin.HasSameVersion());
+		internal static bool HasCustomPluginsLoaded => ActivePlugins?.Any(plugin => !(plugin is OfficialPlugin officialPlugin) || !officialPlugin.HasSameVersion()) == true;
 
 		[ImportMany]
 		internal static ImmutableHashSet<IPlugin>? ActivePlugins { get; private set; }
 
-		private static bool HasActivePluginsLoaded => ActivePlugins?.Count > 0;
-
 		internal static async Task<StringComparer> GetBotsComparer() {
-			if (!HasActivePluginsLoaded) {
+			if (ActivePlugins == null) {
 				return StringComparer.Ordinal;
 			}
 
@@ -64,7 +62,7 @@ namespace ArchiSteamFarm.Plugins {
 		}
 
 		internal static async Task<uint> GetChangeNumberToStartFrom() {
-			if (!HasActivePluginsLoaded) {
+			if (ActivePlugins == null) {
 				return 0;
 			}
 
@@ -88,7 +86,7 @@ namespace ArchiSteamFarm.Plugins {
 		}
 
 		internal static bool InitPlugins() {
-			if (HasActivePluginsLoaded) {
+			if (ActivePlugins != null) {
 				return false;
 			}
 
@@ -189,7 +187,7 @@ namespace ArchiSteamFarm.Plugins {
 		}
 
 		internal static async Task OnASFInitModules(IReadOnlyDictionary<string, JToken>? additionalConfigProperties = null) {
-			if (!HasActivePluginsLoaded) {
+			if ((ActivePlugins == null) || (ActivePlugins.Count == 0)) {
 				return;
 			}
 
@@ -205,7 +203,7 @@ namespace ArchiSteamFarm.Plugins {
 				throw new ArgumentNullException(nameof(bot) + " || " + nameof(steamID) + " || " + nameof(message) + " || " + nameof(args));
 			}
 
-			if (!HasActivePluginsLoaded) {
+			if ((ActivePlugins == null) || (ActivePlugins.Count == 0)) {
 				return null;
 			}
 
@@ -227,7 +225,7 @@ namespace ArchiSteamFarm.Plugins {
 				throw new ArgumentNullException(nameof(bot));
 			}
 
-			if (!HasActivePluginsLoaded) {
+			if ((ActivePlugins == null) || (ActivePlugins.Count == 0)) {
 				return;
 			}
 
@@ -243,7 +241,7 @@ namespace ArchiSteamFarm.Plugins {
 				throw new ArgumentNullException(nameof(bot));
 			}
 
-			if (!HasActivePluginsLoaded) {
+			if ((ActivePlugins == null) || (ActivePlugins.Count == 0)) {
 				return;
 			}
 
@@ -259,7 +257,7 @@ namespace ArchiSteamFarm.Plugins {
 				throw new ArgumentNullException(nameof(bot));
 			}
 
-			if (!HasActivePluginsLoaded) {
+			if ((ActivePlugins == null) || (ActivePlugins.Count == 0)) {
 				return;
 			}
 
@@ -275,7 +273,7 @@ namespace ArchiSteamFarm.Plugins {
 				throw new ArgumentNullException(nameof(bot));
 			}
 
-			if (!HasActivePluginsLoaded) {
+			if ((ActivePlugins == null) || (ActivePlugins.Count == 0)) {
 				return;
 			}
 
@@ -291,7 +289,7 @@ namespace ArchiSteamFarm.Plugins {
 				throw new ArgumentNullException(nameof(bot));
 			}
 
-			if (!HasActivePluginsLoaded) {
+			if ((ActivePlugins == null) || (ActivePlugins.Count == 0)) {
 				return;
 			}
 
@@ -307,7 +305,7 @@ namespace ArchiSteamFarm.Plugins {
 				throw new ArgumentNullException(nameof(bot) + " || " + nameof(steamID));
 			}
 
-			if (!HasActivePluginsLoaded) {
+			if ((ActivePlugins == null) || (ActivePlugins.Count == 0)) {
 				return false;
 			}
 
@@ -329,7 +327,7 @@ namespace ArchiSteamFarm.Plugins {
 				throw new ArgumentNullException(nameof(bot));
 			}
 
-			if (!HasActivePluginsLoaded) {
+			if ((ActivePlugins == null) || (ActivePlugins.Count == 0)) {
 				return;
 			}
 
@@ -345,7 +343,7 @@ namespace ArchiSteamFarm.Plugins {
 				throw new ArgumentNullException(nameof(bot));
 			}
 
-			if (!HasActivePluginsLoaded) {
+			if ((ActivePlugins == null) || (ActivePlugins.Count == 0)) {
 				return;
 			}
 
@@ -361,7 +359,7 @@ namespace ArchiSteamFarm.Plugins {
 				throw new ArgumentNullException(nameof(bot));
 			}
 
-			if (!HasActivePluginsLoaded) {
+			if ((ActivePlugins == null) || (ActivePlugins.Count == 0)) {
 				return;
 			}
 
@@ -377,7 +375,7 @@ namespace ArchiSteamFarm.Plugins {
 				throw new ArgumentNullException(nameof(bot) + " || " + nameof(steamID) + " || " + nameof(message));
 			}
 
-			if (!HasActivePluginsLoaded) {
+			if ((ActivePlugins == null) || (ActivePlugins.Count == 0)) {
 				return null;
 			}
 
@@ -399,7 +397,7 @@ namespace ArchiSteamFarm.Plugins {
 				throw new ArgumentNullException(nameof(bot) + " || " + nameof(callbackManager));
 			}
 
-			if (!HasActivePluginsLoaded) {
+			if ((ActivePlugins == null) || (ActivePlugins.Count == 0)) {
 				return;
 			}
 
@@ -415,7 +413,7 @@ namespace ArchiSteamFarm.Plugins {
 				throw new ArgumentNullException(nameof(bot));
 			}
 
-			if (!HasActivePluginsLoaded) {
+			if ((ActivePlugins == null) || (ActivePlugins.Count == 0)) {
 				return null;
 			}
 
@@ -437,7 +435,7 @@ namespace ArchiSteamFarm.Plugins {
 				throw new ArgumentNullException(nameof(bot) + " || " + nameof(tradeOffer));
 			}
 
-			if (!HasActivePluginsLoaded) {
+			if ((ActivePlugins == null) || (ActivePlugins.Count == 0)) {
 				return false;
 			}
 
@@ -459,7 +457,7 @@ namespace ArchiSteamFarm.Plugins {
 				throw new ArgumentNullException(nameof(bot) + " || " + nameof(tradeResults));
 			}
 
-			if (!HasActivePluginsLoaded) {
+			if ((ActivePlugins == null) || (ActivePlugins.Count == 0)) {
 				return;
 			}
 
@@ -475,7 +473,7 @@ namespace ArchiSteamFarm.Plugins {
 				throw new ArgumentNullException(nameof(bot) + " || " + nameof(newNotifications));
 			}
 
-			if (!HasActivePluginsLoaded) {
+			if ((ActivePlugins == null) || (ActivePlugins.Count == 0)) {
 				return;
 			}
 
@@ -491,7 +489,7 @@ namespace ArchiSteamFarm.Plugins {
 				throw new ArgumentNullException(nameof(currentChangeNumber) + " || " + nameof(appChanges) + " || " + nameof(packageChanges));
 			}
 
-			if (!HasActivePluginsLoaded) {
+			if ((ActivePlugins == null) || (ActivePlugins.Count == 0)) {
 				return;
 			}
 
@@ -507,7 +505,7 @@ namespace ArchiSteamFarm.Plugins {
 				throw new ArgumentNullException(nameof(currentChangeNumber));
 			}
 
-			if (!HasActivePluginsLoaded) {
+			if ((ActivePlugins == null) || (ActivePlugins.Count == 0)) {
 				return;
 			}
 

ArchiSteamFarm/Program.cs

@@ -61,7 +61,7 @@ namespace ArchiSteamFarm {
 				return;
 			}
 
-			string? executableName = Path.GetFileNameWithoutExtension(OS.ProcessFileName);
+			string executableName = Path.GetFileNameWithoutExtension(OS.ProcessFileName);
 
 			if (string.IsNullOrEmpty(executableName)) {
 				throw new ArgumentNullException(nameof(executableName));
@@ -223,7 +223,7 @@ namespace ArchiSteamFarm {
 			if (!string.IsNullOrEmpty(ASF.GlobalConfig?.CurrentCulture)) {
 				try {
 					// GetCultureInfo() would be better but we can't use it for specifying neutral cultures such as "en"
-					CultureInfo culture = CultureInfo.CreateSpecificCulture(ASF.GlobalConfig!.CurrentCulture);
+					CultureInfo culture = CultureInfo.CreateSpecificCulture(ASF.GlobalConfig!.CurrentCulture!);
 					CultureInfo.DefaultThreadCurrentCulture = CultureInfo.DefaultThreadCurrentUICulture = culture;
 				} catch (Exception e) {
 					ASF.ArchiLogger.LogGenericWarningException(e);
@@ -385,8 +385,12 @@ namespace ArchiSteamFarm {
 		private static async void OnProcessExit(object? sender, EventArgs e) => await Shutdown().ConfigureAwait(false);
 
 		private static async void OnUnhandledException(object? sender, UnhandledExceptionEventArgs e) {
-			if (e?.ExceptionObject == null) {
-				throw new ArgumentNullException(nameof(e) + " || " + nameof(e.ExceptionObject));
+			if (e == null) {
+				throw new ArgumentNullException(nameof(e));
+			}
+
+			if (e.ExceptionObject == null) {
+				throw new ArgumentNullException(nameof(e.ExceptionObject));
 			}
 
 			await ASF.ArchiLogger.LogFatalException((Exception) e.ExceptionObject).ConfigureAwait(false);
@@ -394,8 +398,12 @@ namespace ArchiSteamFarm {
 		}
 
 		private static async void OnUnobservedTaskException(object? sender, UnobservedTaskExceptionEventArgs e) {
-			if (e?.Exception == null) {
-				throw new ArgumentNullException(nameof(e) + " || " + nameof(e.Exception));
+			if (e == null) {
+				throw new ArgumentNullException(nameof(e));
+			}
+
+			if (e.Exception == null) {
+				throw new ArgumentNullException(nameof(e.Exception));
 			}
 
 			await ASF.ArchiLogger.LogFatalException(e.Exception).ConfigureAwait(false);
@@ -414,7 +422,7 @@ namespace ArchiSteamFarm {
 				string? envCryptKey = Environment.GetEnvironmentVariable(SharedInfo.EnvironmentVariableCryptKey);
 
 				if (!string.IsNullOrEmpty(envCryptKey)) {
-					HandleCryptKeyArgument(envCryptKey);
+					HandleCryptKeyArgument(envCryptKey!);
 				}
 			} catch (Exception e) {
 				ASF.ArchiLogger.LogGenericException(e);
@@ -462,13 +470,13 @@ namespace ArchiSteamFarm {
 				string? envNetworkGroup = Environment.GetEnvironmentVariable(SharedInfo.EnvironmentVariableNetworkGroup);
 
 				if (!string.IsNullOrEmpty(envNetworkGroup)) {
-					HandleNetworkGroupArgument(envNetworkGroup);
+					HandleNetworkGroupArgument(envNetworkGroup!);
 				}
 
 				string? envPath = Environment.GetEnvironmentVariable(SharedInfo.EnvironmentVariablePath);
 
 				if (!string.IsNullOrEmpty(envPath)) {
-					HandlePathArgument(envPath);
+					HandlePathArgument(envPath!);
 				}
 			} catch (Exception e) {
 				ASF.ArchiLogger.LogGenericException(e);

ArchiSteamFarm/RuntimeCompatibility.cs

@@ -29,7 +29,6 @@ using Microsoft.AspNetCore.Hosting;
 using System.Collections.Generic;
 using System.Net.WebSockets;
 using System.Threading;
-
 #endif
 
 namespace ArchiSteamFarm {

ArchiSteamFarm/Statistics.cs

@@ -355,9 +355,7 @@ namespace ArchiSteamFarm {
 
 		private async Task<(bool ShouldContinueMatching, bool TradedSomething)> MatchActivelyRound(IReadOnlyCollection<Steam.Asset.EType> acceptedMatchableTypes, IDictionary<ulong, (byte Tries, ISet<ulong>? GivenAssetIDs, ISet<ulong>? ReceivedAssetIDs)> triedSteamIDs) {
 			if ((acceptedMatchableTypes == null) || (acceptedMatchableTypes.Count == 0) || (triedSteamIDs == null)) {
-				Bot.ArchiLogger.LogNullError(nameof(acceptedMatchableTypes) + " || " + nameof(triedSteamIDs));
-
-				return (false, false);
+				throw new ArgumentNullException(nameof(acceptedMatchableTypes) + " || " + nameof(triedSteamIDs));
 			}
 
 			HashSet<Steam.Asset> ourInventory;

ArchiSteamFarm/SteamKit2/InMemoryServerListProvider.cs

@@ -36,9 +36,7 @@ namespace ArchiSteamFarm.SteamKit2 {
 
 		public Task UpdateServerListAsync(IEnumerable<ServerRecord> endpoints) {
 			if (endpoints == null) {
-				ASF.ArchiLogger.LogNullError(nameof(endpoints));
-
-				return Task.CompletedTask;
+				throw new ArgumentNullException(nameof(endpoints));
 			}
 
 			HashSet<ServerRecordEndPoint> newServerRecords = endpoints.Select(ep => new ServerRecordEndPoint(ep.GetHost(), (ushort) ep.GetPort(), ep.ProtocolTypes)).ToHashSet();

ArchiSteamFarm/Trading.cs

@@ -265,7 +265,7 @@ namespace ArchiSteamFarm {
 			}
 
 			foreach (((uint RealAppID, Steam.Asset.EType Type, Steam.Asset.ERarity Rarity) set, Dictionary<ulong, uint> state) in tradableState) {
-				if (!fullState.TryGetValue(set, out Dictionary<ulong, uint>? fullSet) || (fullSet == null) || (fullSet.Count == 0)) {
+				if (!fullState.TryGetValue(set, out Dictionary<ulong, uint>? fullSet) || (fullSet.Count == 0)) {
 					throw new ArgumentNullException(nameof(fullSet));
 				}
 

ArchiSteamFarm/WebBrowser.cs

@@ -671,7 +671,7 @@ namespace ArchiSteamFarm {
 				}
 
 				if (!string.IsNullOrEmpty(referer)) {
-					request.Headers.Referrer = new Uri(referer);
+					request.Headers.Referrer = new Uri(referer!);
 				}
 
 				if (Debugging.IsUserDebugging) {