Ienumerable changes

Libraries/SPTarkov.Server.Core/Controllers/RagfairController.cs

@@ -379,7 +379,7 @@ public class RagfairController(
         var offers = ragfairOfferService.GetOffersOfType(getPriceRequest.TemplateId);
 
         // Offers exist for item, get averages of what's listed
-        if (offers?.Count > 0)
+        if (offers.Any())
         {
             // These get calculated while iterating through the list below
             var minMax = new MinMax<double>(int.MaxValue, 0);
@@ -412,7 +412,7 @@ public class RagfairController(
     }
 
     protected double GetAveragePriceFromOffers(
-        List<RagfairOffer> offers,
+        IEnumerable<RagfairOffer> offers,
         MinMax<double> minMax,
         bool ignoreTraderOffers
     )

Libraries/SPTarkov.Server.Core/Generators/BotEquipmentModGenerator.cs

@@ -197,7 +197,8 @@ public class BotEquipmentModGenerator(
                 );
                 switch (plateSlotFilteringOutcome.Result)
                 {
-                    case Result.UNKNOWN_FAILURE or Result.NO_DEFAULT_FILTER:
+                    case Result.UNKNOWN_FAILURE
+                    or Result.NO_DEFAULT_FILTER:
                         if (logger.IsLogEnabled(LogLevel.Debug))
                         {
                             logger.Debug(
@@ -692,6 +693,7 @@ public class BotEquipmentModGenerator(
             // Force spawn chance to be 100% to ensure it gets added
             if (
                 modSlot == "mod_handguard"
+                && modToAddTemplate.Properties?.Slots is not null
                 && modToAddTemplate.Properties.Slots.Any(slot => slot.Name == "mod_handguard")
                 && !request.Weapon.Any(item => item.SlotId == "mod_launcher")
             )
@@ -772,6 +774,7 @@ public class BotEquipmentModGenerator(
                 if (
                     isRandomisableSlot
                     && !containsModInPool
+                    && modToAddTemplate.Properties?.Slots is not null
                     && modToAddTemplate.Properties.Slots.Any()
                 )
                 {
@@ -835,9 +838,15 @@ public class BotEquipmentModGenerator(
     /// <returns>True it lacks cartridges/chamber slots</returns>
     protected bool ItemLacksSlotsCartridgesAndChambers(TemplateItem item)
     {
-        return item.Properties.Slots?.Count == 0
+        if (item.Properties is null)
-            && item.Properties.Cartridges?.Count == 0
+        {
-            && item.Properties.Chambers?.Count == 0;
+            return true;
+        }
+
+        return item.Properties.Slots is null
+            || !item.Properties.Slots.Any()
+                && item.Properties.Cartridges?.Count == 0
+                && item.Properties.Chambers?.Count == 0;
     }
 
     /// <summary>
@@ -854,7 +863,9 @@ public class BotEquipmentModGenerator(
     )
     {
         // Can the stock hold child items
-        var hasSubSlots = modToAddTemplate.Properties.Slots?.Count > 0;
+        var hasSubSlots =
+            modToAddTemplate.Properties?.Slots is not null
+            && modToAddTemplate.Properties.Slots.Any();
 
         return (_stockSlots.Contains(modSlot) && hasSubSlots)
             || botEquipConfig.ForceStock.GetValueOrDefault(false);
@@ -1280,8 +1291,8 @@ public class BotEquipmentModGenerator(
         var desiredMagazineTpls = modPool.Where(magTpl =>
         {
             var magazineDb = itemHelper.GetItem(magTpl).Value;
-            return magazineDb.Properties is not null
+            return magazineDb.Properties?.Cartridges is not null
-                && magazineDb.Properties.Cartridges.FirstOrDefault().MaxCount
+                && magazineDb.Properties.Cartridges.FirstOrDefault()?.MaxCount
                     >= minMagSizeFromSettings;
         });
 
@@ -1546,7 +1557,7 @@ public class BotEquipmentModGenerator(
         // Mod isn't in existing pool, only add if it has no children and exists inside parent filter
         if (
             (parentSlotCompatibleItems?.Contains(matchingModFromPreset.Template) ?? false)
-            && itemHelper.GetItem(matchingModFromPreset.Template).Value.Properties.Slots?.Count == 0
+            && !itemHelper.GetItem(matchingModFromPreset.Template).Value.Properties.Slots.Any()
         )
         {
             // Chosen mod has no conflicts + no children + is in parent compat list
@@ -2070,22 +2081,23 @@ public class BotEquipmentModGenerator(
 
         // Filter items that are not directly scopes OR mounts that do not hold the type of scope we allow for this weapon type
         HashSet<MongoId> filteredScopesAndMods = [];
-        foreach (var item in scopes)
+        foreach (var scopeTpl in scopes)
         {
             // Mods is a scope, check base class is allowed
-            if (itemHelper.IsOfBaseclasses(item, whitelistedSightTypes))
+            if (itemHelper.IsOfBaseclasses(scopeTpl, whitelistedSightTypes))
             {
                 // Add mod to allowed list
-                filteredScopesAndMods.Add(item);
+                filteredScopesAndMods.Add(scopeTpl);
                 continue;
             }
 
             // Edge case, what if item is a mount for a scope and not directly a scope?
             // Check item is mount + has child items
-            var itemDetails = itemHelper.GetItem(item).Value;
+            var itemDetails = itemHelper.GetItem(scopeTpl).Value;
             if (
-                itemHelper.IsOfBaseclass(item, BaseClasses.MOUNT)
+                itemDetails?.Properties?.Slots is not null
                 && itemDetails.Properties.Slots.Any()
+                && itemHelper.IsOfBaseclass(scopeTpl, BaseClasses.MOUNT)
             )
             {
                 // Check to see if mount has a scope slot (only include primary slot, ignore the rest like the backup sight slots)
@@ -2107,7 +2119,7 @@ public class BotEquipmentModGenerator(
                 )
                 // Add mod to allowed list
                 {
-                    filteredScopesAndMods.Add(item);
+                    filteredScopesAndMods.Add(scopeTpl);
                 }
             }
         }

Libraries/SPTarkov.Server.Core/Generators/BotInventoryGenerator.cs

@@ -615,7 +615,11 @@ public class BotInventoryGenerator(
                 settings.GenerateModsBlacklist != null
                 && settings.GenerateModsBlacklist.Contains(pickedItemDb.Id);
             // Does item have slots for sub-mods to be inserted into
-            if (pickedItemDb.Properties?.Slots?.Count > 0 && !itemIsOnGenerateModBlacklist)
+            if (
+                pickedItemDb.Properties?.Slots is not null
+                && pickedItemDb.Properties.Slots.Any()
+                && !itemIsOnGenerateModBlacklist
+            )
             {
                 var childItemsToAdd = botEquipmentModGenerator.GenerateModsForEquipment(
                     [item],

Libraries/SPTarkov.Server.Core/Generators/BotLootGenerator.cs

@@ -285,7 +285,7 @@ public class BotLootGenerator(
         var itemPriceLimits = GetSingleItemLootPriceLimits(botLevel, isPmc);
 
         // Backpack - generate loot if they have one
-        if (containersBotHasAvailable.Contains(EquipmentSlots.Backpack))
+        if (containersBotHasAvailable.Contains(EquipmentSlots.Backpack) && backpackLootCount > 0)
         {
             // Add randomly generated weapon to PMC backpacks
             if (isPmc && randomUtil.GetChance100(_pmcConfig.LooseWeaponInBackpackChancePercent))
@@ -506,9 +506,7 @@ public class BotLootGenerator(
     )
     {
         // Loot pool has items
-        var poolSize = pool.Count;
+        if (pool.Count <= 0)
-
-        if (poolSize <= 0)
         {
             return;
         }

Libraries/SPTarkov.Server.Core/Generators/BotWeaponGenerator.cs

@@ -905,9 +905,9 @@ public class BotWeaponGenerator(
     /// <param name="weaponMods">Weapon with children.</param>
     /// <param name="ubglMod">Underbarrrel grenade launcher item.</param>
     /// <param name="ubglAmmoTpl">Grenade ammo template.</param>
-    protected void FillUbgl(IEnumerable<Item> weaponMods, Item ubglMod, MongoId ubglAmmoTpl)
+    protected void FillUbgl(List<Item> weaponMods, Item ubglMod, MongoId ubglAmmoTpl)
     {
-        weaponMods.Append(
+        weaponMods.Add(
             new Item
             {
                 Id = new MongoId(),

Libraries/SPTarkov.Server.Core/Generators/FenceBaseAssortGenerator.cs

@@ -77,7 +77,7 @@ public class FenceBaseAssortGenerator(
             // Only allow rigs with no slots (carrier rigs)
             if (
                 itemHelper.IsOfBaseclass(itemId, BaseClasses.VEST)
-                && (rootItemDb.Properties?.Slots?.Count ?? 0) > 0
+                && (rootItemDb.Properties?.Slots is not null && rootItemDb.Properties.Slots.Any())
             )
             {
                 continue;
@@ -271,7 +271,8 @@ public class FenceBaseAssortGenerator(
     protected void AddChildrenToArmorModSlots(List<Item> armor, TemplateItem itemDbDetails)
     {
         // Armor has no mods, make no additions
-        var hasMods = itemDbDetails.Properties.Slots.Count > 0;
+        var hasMods =
+            itemDbDetails.Properties?.Slots is not null && itemDbDetails.Properties.Slots.Any();
         if (!hasMods)
         {
             return;

Libraries/SPTarkov.Server.Core/Generators/LocationLootGenerator.cs

@@ -171,7 +171,7 @@ public class LocationLootGenerator(
         // Find all 100% spawn containers
         var staticLootDist = mapData.StaticLoot;
         var guaranteedContainers = GetGuaranteedContainers(allStaticContainersOnMapClone);
-        staticContainerCount += guaranteedContainers.Count;
+        staticContainerCount += guaranteedContainers.Count();
 
         // Add loot to guaranteed containers and add to result
         foreach (
@@ -188,12 +188,12 @@ public class LocationLootGenerator(
         {
             result.Add(containerWithLoot.Template);
 
-            staticLootItemCount += containerWithLoot.Template.Items.Count;
+            staticLootItemCount += containerWithLoot.Template.Items.Count();
         }
 
         if (_logger.IsLogEnabled(LogLevel.Debug))
         {
-            _logger.Debug($"Added {guaranteedContainers.Count} guaranteed containers");
+            _logger.Debug($"Added {guaranteedContainers.Count()} guaranteed containers");
         }
 
         // Randomisation is turned off for location / globally
@@ -202,7 +202,7 @@ public class LocationLootGenerator(
             if (_logger.IsLogEnabled(LogLevel.Debug))
             {
                 _logger.Debug(
-                    $"Container randomisation disabled, Adding: {staticRandomisableContainersOnMap.Count} containers to: {locationId}"
+                    $"Container randomisation disabled, Adding: {staticRandomisableContainersOnMap.Count()} containers to: {locationId}"
                 );
             }
 
@@ -217,7 +217,7 @@ public class LocationLootGenerator(
                 );
                 result.Add(containerWithLoot.Template);
 
-                staticLootItemCount += containerWithLoot.Template.Items.Count;
+                staticLootItemCount += containerWithLoot.Template.Items.Count();
             }
 
             _logger.Success($"A total of {staticLootItemCount} static items spawned");
@@ -320,7 +320,7 @@ public class LocationLootGenerator(
                 result.Add(containerWithLoot.Template);
                 staticContainerCount++;
 
-                staticLootItemCount += containerWithLoot.Template.Items.Count;
+                staticLootItemCount += containerWithLoot.Template.Items.Count();
             }
         }
 
@@ -346,19 +346,17 @@ public class LocationLootGenerator(
     /// </summary>
     /// <param name="staticContainers"></param>
     /// <returns>StaticContainerData array</returns>
-    protected List<StaticContainerData> GetRandomisableContainersOnMap(
+    protected IEnumerable<StaticContainerData> GetRandomisableContainersOnMap(
-        List<StaticContainerData> staticContainers
+        IEnumerable<StaticContainerData> staticContainers
     )
     {
-        return staticContainers
+        return staticContainers.Where(staticContainer =>
-            .Where(staticContainer =>
+            staticContainer.Probability != 1
-                staticContainer.Probability != 1
+            && !staticContainer.Template.IsAlwaysSpawn.GetValueOrDefault(false)
-                && !staticContainer.Template.IsAlwaysSpawn.GetValueOrDefault(false)
+            && !_locationConfig.ContainerRandomisationSettings.ContainerTypesToNotRandomise.Contains(
-                && !_locationConfig.ContainerRandomisationSettings.ContainerTypesToNotRandomise.Contains(
+                staticContainer.Template.Items.FirstOrDefault().Template
-                    staticContainer.Template.Items.FirstOrDefault().Template
-                )
             )
-            .ToList();
+        );
     }
 
     /// <summary>
@@ -366,19 +364,17 @@ public class LocationLootGenerator(
     /// </summary>
     /// <param name="staticContainersOnMap"></param>
     /// <returns>IStaticContainerData array</returns>
-    protected List<StaticContainerData> GetGuaranteedContainers(
+    protected IEnumerable<StaticContainerData> GetGuaranteedContainers(
-        List<StaticContainerData> staticContainersOnMap
+        IEnumerable<StaticContainerData> staticContainersOnMap
     )
     {
-        return staticContainersOnMap
+        return staticContainersOnMap.Where(staticContainer =>
-            .Where(staticContainer =>
+            staticContainer.Probability == 1
-                staticContainer.Probability == 1
+            || staticContainer.Template.IsAlwaysSpawn.GetValueOrDefault(false)
-                || staticContainer.Template.IsAlwaysSpawn.GetValueOrDefault(false)
+            || _locationConfig.ContainerRandomisationSettings.ContainerTypesToNotRandomise.Contains(
-                || _locationConfig.ContainerRandomisationSettings.ContainerTypesToNotRandomise.Contains(
+                staticContainer.Template.Items.FirstOrDefault().Template
-                    staticContainer.Template.Items.FirstOrDefault().Template
-                )
             )
-            .ToList();
+        );
     }
 
     /// <summary>
@@ -395,7 +391,7 @@ public class LocationLootGenerator(
     {
         var chosenContainerIds = new List<string>();
 
-        var containerIds = containerData.ContainerIdsWithProbability.Keys.ToList();
+        var containerIds = containerData.ContainerIdsWithProbability.Keys;
         if (containerData.ChosenCount > containerIds.Count)
         {
             if (_logger.IsLogEnabled(LogLevel.Debug))
@@ -405,7 +401,7 @@ public class LocationLootGenerator(
                 );
             }
 
-            return containerIds;
+            return containerIds.ToList();
         }
 
         // Create probability array with all possible container ids in this group and their relative probability of spawning
@@ -429,7 +425,7 @@ public class LocationLootGenerator(
     /// <returns>dictionary keyed by groupId</returns>
     protected Dictionary<string, ContainerGroupCount> GetGroupIdToContainerMappings(
         StaticContainer staticContainerGroupData,
-        List<StaticContainerData> staticContainersOnMap
+        IEnumerable<StaticContainerData> staticContainersOnMap
     )
     {
         // Create dictionary of all group ids and choose a count of containers the map will spawn of that group
@@ -532,7 +528,7 @@ public class LocationLootGenerator(
     /// <returns>StaticContainerData</returns>
     protected StaticContainerData AddLootToContainer(
         StaticContainerData staticContainer,
-        List<StaticForced>? staticForced,
+        IEnumerable<StaticForced>? staticForced,
         Dictionary<string, StaticLootDetails> staticLootDist,
         Dictionary<string, List<StaticAmmoDetails>> staticAmmoDist,
         string locationName
@@ -639,9 +635,8 @@ public class LocationLootGenerator(
             };
 
             // Add loot to container before returning
-            containerClone.Template.Items.AddRange(
+            var itemsToAdd = items.Select(item => item.ToLootItem()); // Convert into correct output type first
-                items.Select(item => item.ToLootItem()).ToList() // Convert into correct output type first
+            containerClone.Template.Items = containerClone.Template.Items.Union(itemsToAdd);
-            );
         }
 
         return containerClone;
@@ -776,16 +771,12 @@ public class LocationLootGenerator(
         // Remove christmas items from loot data
         if (!_seasonalEventService.ChristmasEventEnabled())
         {
-            dynamicLootDist.Spawnpoints = dynamicLootDist
+            dynamicLootDist.Spawnpoints = dynamicLootDist.Spawnpoints.Where(point =>
-                .Spawnpoints.Where(point =>
+                !point.Template.Id.StartsWith("christmas", StringComparison.OrdinalIgnoreCase)
-                    !point.Template.Id.StartsWith("christmas", StringComparison.OrdinalIgnoreCase)
+            );
-                )
+            dynamicLootDist.SpawnpointsForced = dynamicLootDist.SpawnpointsForced.Where(point =>
-                .ToList();
+                !point.Template.Id.StartsWith("christmas", StringComparison.OrdinalIgnoreCase)
-            dynamicLootDist.SpawnpointsForced = dynamicLootDist
+            );
-                .SpawnpointsForced.Where(point =>
-                    !point.Template.Id.StartsWith("christmas", StringComparison.OrdinalIgnoreCase)
-                )
-                .ToList();
         }
 
         // Build the list of forced loot from both `SpawnpointsForced` and any point marked `IsAlwaysSpawn`
@@ -929,7 +920,7 @@ public class LocationLootGenerator(
             }
 
             // Spawn point has no items after filtering, skip
-            if (spawnPoint.Template.Items is null || spawnPoint.Template.Items.Count == 0)
+            if (spawnPoint.Template.Items is null || !spawnPoint.Template.Items.Any())
             {
                 if (_logger.IsLogEnabled(LogLevel.Debug))
                 {
@@ -1031,7 +1022,7 @@ public class LocationLootGenerator(
     /// <param name="staticAmmoDist"></param>
     /// <returns>Collection of spawn points with forced loot in them</returns>
     protected List<SpawnpointTemplate> GetForcedDynamicLoot(
-        List<Spawnpoint> forcedSpawnPoints,
+        IEnumerable<Spawnpoint> forcedSpawnPoints,
         string locationName,
         Dictionary<string, List<StaticAmmoDetails>> staticAmmoDist
     )
@@ -1105,7 +1096,7 @@ public class LocationLootGenerator(
     /// <returns> ContainerItem object </returns>
     protected ContainerItem CreateDynamicLootItem(
         SptLootItem chosenItem,
-        List<SptLootItem> lootItems,
+        IEnumerable<SptLootItem> lootItems,
         Dictionary<string, List<StaticAmmoDetails>> staticAmmoDist
     )
     {
@@ -1282,17 +1273,20 @@ public class LocationLootGenerator(
         var defaultPreset = _presetHelper.GetDefaultPreset(chosenTpl);
         if (defaultPreset is not null)
         {
-            var presetAndModsClone = _cloner.Clone(defaultPreset.Items).ReplaceIDs().ToList();
+            var presetAndModsClone = _cloner.Clone(defaultPreset.Items).ReplaceIDs();
             presetAndModsClone.RemapRootItemId();
 
             // Use original items parentId otherwise item doesn't get added to container correctly
             presetAndModsClone.FirstOrDefault().ParentId = rootItem.ParentId;
-            items = presetAndModsClone;
+            items = presetAndModsClone.ToList();
         }
         else
         {
             // We make base item in calling method, no need to do it here
-            if ((armorDbTemplate.Properties.Slots?.Count ?? 0) > 0)
+            if (
+                armorDbTemplate.Properties?.Slots is not null
+                && armorDbTemplate.Properties.Slots.Any()
+            )
             {
                 items = _itemHelper.AddChildSlotItems(
                     items,

Libraries/SPTarkov.Server.Core/Generators/RagfairOfferGenerator.cs

@@ -343,9 +343,9 @@ public class RagfairOfferGenerator(
     ///     Create multiple offers for items by using a unique list of items we've generated previously
     /// </summary>
     /// <param name="expiredOffers"> Optional, expired offers to regenerate </param>
-    public void GenerateDynamicOffers(List<List<Item>>? expiredOffers = null)
+    public void GenerateDynamicOffers(IEnumerable<List<Item>>? expiredOffers = null)
     {
-        var replacingExpiredOffers = (expiredOffers?.Count ?? 0) > 0;
+        var replacingExpiredOffers = expiredOffers is not null && expiredOffers.Any();
 
         var stopwatch = Stopwatch.StartNew();
         // get assort items from param if they exist, otherwise grab freshly generated assorts
@@ -356,7 +356,7 @@ public class RagfairOfferGenerator(
         if (logger.IsLogEnabled(LogLevel.Debug) && stopwatch.ElapsedMilliseconds > 0)
         {
             logger.Debug(
-                $"Took {stopwatch.ElapsedMilliseconds}ms to GetRagfairAssorts - {assortItemsToProcess.Count} items"
+                $"Took {stopwatch.ElapsedMilliseconds}ms to GetRagfairAssorts - {assortItemsToProcess.Count()} items"
             );
         }
 

Libraries/SPTarkov.Server.Core/Generators/RepeatableQuestGeneration/ExplorationQuestGenerator.cs

@@ -209,11 +209,14 @@ public class ExplorationQuestGenerator(
     /// <param name="locationKey">Map id (e.g. factory4_day)</param>
     /// <param name="playerGroup">Pmc/Scav</param>
     /// <returns>List of Exit objects</returns>
-    protected List<Exit>? GetLocationExitsForSide(string locationKey, PlayerGroup playerGroup)
+    protected IEnumerable<Exit>? GetLocationExitsForSide(
+        string locationKey,
+        PlayerGroup playerGroup
+    )
     {
         var mapExtracts = databaseService.GetLocation(locationKey.ToLowerInvariant())?.AllExtracts;
 
-        return mapExtracts?.Where(exit => exit.Side == Enum.GetName(playerGroup)).ToList();
+        return mapExtracts?.Where(exit => exit.Side == Enum.GetName(playerGroup));
     }
 
     /// <summary>
@@ -308,18 +311,16 @@ public class ExplorationQuestGenerator(
         }
 
         // Only get exits that have a greater than 0% chance to spawn
-        var exitPool = mapExits.Where(exit => exit.Chance > 0).ToList();
+        var exitPool = mapExits.Where(exit => exit.Chance > 0);
 
         // Exclude exits with a requirement to leave (e.g. car extracts)
-        var possibleExits = exitPool
+        var possibleExits = exitPool.Where(exit =>
-            .Where(exit =>
+            repeatableConfig.QuestConfig.Exploration.SpecificExits.PassageRequirementWhitelist.Contains(
-                repeatableConfig.QuestConfig.Exploration.SpecificExits.PassageRequirementWhitelist.Contains(
+                "PassageRequirement"
-                    "PassageRequirement"
-                )
             )
-            .ToList();
+        );
 
-        if (possibleExits.Count == 0)
+        if (!possibleExits.Any())
         {
             logger.Error(
                 localisationService.GetText(
@@ -332,7 +333,7 @@ public class ExplorationQuestGenerator(
         }
 
         // Choose one of the exits we filtered above
-        var chosenExit = randomUtil.DrawRandomFromList(possibleExits)[0];
+        var chosenExit = randomUtil.DrawRandomFromList(possibleExits.ToList())[0];
 
         // Create a quest condition to leave raid via chosen exit
         var exitCondition = GenerateQuestConditionCounter(chosenExit);

Libraries/SPTarkov.Server.Core/Helpers/BotGeneratorHelper.cs

@@ -596,7 +596,7 @@ public class BotGeneratorHelper(
                 continue;
             }
 
-            if (itemDbDetails?.Properties?.Grids?.Count == 0)
+            if (itemDbDetails?.Properties?.Grids is null || !itemDbDetails.Properties.Grids.Any())
             // Container has no slots to hold items
             {
                 continue;
@@ -611,15 +611,11 @@ public class BotGeneratorHelper(
 
             // Iterate over each grid in the container and look for a big enough space for the item to be placed in
             var currentGridCount = 1;
-            var totalSlotGridCount = itemDbDetails?.Properties?.Grids?.Count;
+            var totalSlotGridCount = itemDbDetails?.Properties?.Grids?.Count();
             foreach (var slotGrid in itemDbDetails?.Properties?.Grids ?? [])
             {
                 // Grid is empty, skip or item size is bigger than grid
-                if (
+                if (IsGridSmallerThanItem(slotGrid, itemWidth, itemHeight))
-                    slotGrid.Props?.CellsH == 0
-                    || slotGrid.Props?.CellsV == 0
-                    || itemWidth * itemHeight > slotGrid.Props?.CellsV * slotGrid.Props?.CellsH
-                )
                 {
                     continue;
                 }
@@ -711,6 +707,13 @@ public class BotGeneratorHelper(
         return ItemAddedResult.NO_SPACE;
     }
 
+    protected static bool IsGridSmallerThanItem(Grid slotGrid, int itemWidth, int itemHeight)
+    {
+        return slotGrid.Props?.CellsH == 0
+            || slotGrid.Props?.CellsV == 0
+            || itemWidth * itemHeight > slotGrid.Props?.CellsV * slotGrid.Props?.CellsH;
+    }
+
     /// <summary>
     ///     Take a list of items and check if they need children + add them
     /// </summary>

Libraries/SPTarkov.Server.Core/Helpers/BotWeaponGeneratorHelper.cs

@@ -44,7 +44,7 @@ public class BotWeaponGeneratorHelper(
             chamberBulletCount =
                 ammoMaxStackSize == 1
                     ? 1 // Rotating grenade launcher
-                    : magTemplate.Properties.Slots.Count; // Shotguns/revolvers. We count the number of camoras as the _max_count of the magazine is 0
+                    : magTemplate.Properties.Slots.Count(); // Shotguns/revolvers. We count the number of camoras as the _max_count of the magazine is 0
         }
         else if (parentItem.Id == BaseClasses.UBGL)
         {

Libraries/SPTarkov.Server.Core/Helpers/ItemHelper.cs

@@ -369,9 +369,10 @@ public class ItemHelper(
     {
         var itemTemplate = GetItem(itemTpl);
 
-        return itemTemplate.Value.Properties.Slots.Any(slot =>
+        return itemTemplate.Value?.Properties?.Slots is not null
-            _removablePlateSlotIds.Contains(slot.Name.ToLowerInvariant())
+            && itemTemplate.Value.Properties.Slots.Any(slot =>
-        );
+                _removablePlateSlotIds.Contains(slot.Name.ToLowerInvariant())
+            );
     }
 
     /// <summary>
@@ -543,7 +544,7 @@ public class ItemHelper(
     {
         if (databaseService.GetItems().TryGetValue(itemTpl, out var item))
         {
-            return item?.Properties?.Slots?.Count > 0;
+            return item.Properties?.Slots is not null && item.Properties.Slots.Any();
         }
 
         return false;
@@ -1534,7 +1535,7 @@ public class ItemHelper(
             magTemplate.Id,
             BaseClasses.SPRING_DRIVEN_CYLINDER
         )
-            ? magProps?.Slots?.Count // Edge case for rotating grenade launcher magazine
+            ? magProps?.Slots?.Count() // Edge case for rotating grenade launcher magazine
             : magProps?.Cartridges?.FirstOrDefault()?.MaxCount;
 
         if (magazineCartridgeMaxCount is null)
@@ -2001,8 +2002,8 @@ public class ItemHelper(
         var containerTemplate = GetItem(containerTpl).Value;
 
         // Get height/width
-        var height = containerTemplate.Properties.Grids[0].Props.CellsV;
+        var height = containerTemplate.Properties.Grids.First().Props.CellsV;
-        var width = containerTemplate.Properties.Grids[0].Props.CellsH;
+        var width = containerTemplate.Properties.Grids.First().Props.CellsH;
 
         return GetBlankContainerMap(width.Value, height.Value);
     }

Libraries/SPTarkov.Server.Core/Helpers/RagfairOfferHelper.cs

@@ -225,7 +225,7 @@ public class RagfairOfferHelper(
         PmcData pmcData
     )
     {
-        var offersMap = new Dictionary<string, List<RagfairOffer>>();
+        var offersMap = new Dictionary<MongoId, List<RagfairOffer>>();
         var offersToReturn = new List<RagfairOffer>();
         var playerIsFleaBanned = pmcData.PlayerIsFleaBanned(timeUtil.GetTimeStamp());
         var tieredFlea = _ragfairConfig.TieredFlea;

Libraries/SPTarkov.Server.Core/Models/Eft/Common/Globals.cs

@@ -720,7 +720,7 @@ public record PveSettings
     [JsonExtensionData]
     public Dictionary<string, object>? ExtensionData { get; set; }
 
-    public List<string> AvailableVersions { get; set; }
+    public IEnumerable<string> AvailableVersions { get; set; }
 
     public bool ModeEnabled { get; set; }
 }
@@ -730,7 +730,7 @@ public record CoopSettings
     [JsonExtensionData]
     public Dictionary<string, object>? ExtensionData { get; set; }
 
-    public List<string> AvailableVersions { get; set; }
+    public IEnumerable<string> AvailableVersions { get; set; }
 }
 
 public record RunddansSettings
@@ -739,7 +739,7 @@ public record RunddansSettings
     public Dictionary<string, object>? ExtensionData { get; set; }
 
     [JsonPropertyName("accessKeys")]
-    public List<string> AccessKeys { get; set; }
+    public IEnumerable<string> AccessKeys { get; set; }
 
     [JsonPropertyName("active")]
     public bool Active { get; set; }
@@ -751,7 +751,7 @@ public record RunddansSettings
     public double ApplyFrozenEverySec { get; set; }
 
     [JsonPropertyName("consumables")]
-    public List<string> Consumables { get; set; }
+    public IEnumerable<string> Consumables { get; set; }
 
     [JsonPropertyName("drunkImmunitySec")]
     public double DrunkImmunitySec { get; set; }
@@ -772,13 +772,13 @@ public record RunddansSettings
     public double KnifeCritChanceToBreak { get; set; }
 
     [JsonPropertyName("locations")]
-    public List<string> Locations { get; set; }
+    public IEnumerable<string> Locations { get; set; }
 
     [JsonPropertyName("multitoolRepairSec")]
     public double MultitoolRepairSec { get; set; }
 
     [JsonPropertyName("nonExitsLocations")]
-    public List<string> NonExitsLocations { get; set; }
+    public IEnumerable<string> NonExitsLocations { get; set; }
 
     [JsonPropertyName("rainForFrozen")]
     public double RainForFrozen { get; set; }
@@ -790,7 +790,7 @@ public record RunddansSettings
     public XY SecToBreak { get; set; }
 
     [JsonPropertyName("sleighLocations")]
-    public List<string> SleighLocations { get; set; }
+    public IEnumerable<string> SleighLocations { get; set; }
 }
 
 public record SeasonActivity
@@ -1627,7 +1627,7 @@ public record CustomizationVoice
     public string Voice { get; set; }
 
     [JsonPropertyName("side")]
-    public List<string> Side { get; set; }
+    public IEnumerable<string> Side { get; set; }
 
     [JsonPropertyName("isNotRandom")]
     public bool IsNotRandom { get; set; }
@@ -2310,7 +2310,7 @@ public record Buff
     [JsonPropertyName("SkillName")]
     public string SkillName { get; set; }
 
-    public List<string> AppliesTo { get; set; }
+    public IEnumerable<string> AppliesTo { get; set; }
 }
 
 public record Tremor
@@ -3287,7 +3287,7 @@ public record BTRSettings
     public Dictionary<string, object>? ExtensionData { get; set; }
 
     [JsonPropertyName("LocationsWithBTR")]
-    public List<string> LocationsWithBTR { get; set; }
+    public IEnumerable<string> LocationsWithBTR { get; set; }
 
     [JsonPropertyName("BasePriceTaxi")]
     public double BasePriceTaxi { get; set; }
@@ -3422,7 +3422,7 @@ public record PathConfig
     public string ExitPoint { get; set; }
 
     [JsonPropertyName("pathPoints")]
-    public List<string> PathPoints { get; set; }
+    public IEnumerable<string> PathPoints { get; set; }
 
     [JsonPropertyName("once")]
     public bool Once { get; set; }
@@ -3434,7 +3434,7 @@ public record PathConfig
     public double CircleCount { get; set; }
 
     [JsonPropertyName("skinType")]
-    public List<string> SkinType { get; set; }
+    public IEnumerable<string> SkinType { get; set; }
 }
 
 public record SquadSettings
@@ -4927,10 +4927,10 @@ public record RepairStrategy
     public Dictionary<string, object>? ExtensionData { get; set; }
 
     [JsonPropertyName("BuffTypes")]
-    public List<string> BuffTypes { get; set; }
+    public IEnumerable<string> BuffTypes { get; set; }
 
     [JsonPropertyName("Filter")]
-    public List<string> Filter { get; set; }
+    public IEnumerable<string> Filter { get; set; }
 }
 
 public record BotPreset

Libraries/SPTarkov.Server.Core/Models/Eft/Common/Location.cs

@@ -46,7 +46,7 @@ public record Location
     ///     All possible map extracts
     /// </summary>
     [JsonPropertyName("allExtracts")]
-    public Exit[] AllExtracts { get; set; }
+    public IEnumerable<Exit> AllExtracts { get; set; }
 }
 
 public record StaticContainer
@@ -133,10 +133,10 @@ public record StaticContainerDetails
     public List<SpawnpointTemplate> StaticWeapons { get; set; }
 
     [JsonPropertyName("staticContainers")]
-    public List<StaticContainerData> StaticContainers { get; set; }
+    public IEnumerable<StaticContainerData> StaticContainers { get; set; }
 
     [JsonPropertyName("staticForced")]
-    public List<StaticForced> StaticForced { get; set; }
+    public IEnumerable<StaticForced> StaticForced { get; set; }
 }
 
 public record StaticForced

Libraries/SPTarkov.Server.Core/Models/Eft/Common/LooseLoot.cs

@@ -12,10 +12,10 @@ public record LooseLoot
     public SpawnpointCount? SpawnpointCount { get; set; }
 
     [JsonPropertyName("spawnpointsForced")]
-    public List<Spawnpoint>? SpawnpointsForced { get; set; }
+    public IEnumerable<Spawnpoint>? SpawnpointsForced { get; set; }
 
     [JsonPropertyName("spawnpoints")]
-    public List<Spawnpoint>? Spawnpoints { get; set; }
+    public IEnumerable<Spawnpoint>? Spawnpoints { get; set; }
 }
 
 public record SpawnpointCount
@@ -65,7 +65,7 @@ public record SpawnpointTemplate
     public bool? IsGroupPosition { get; set; }
 
     [JsonPropertyName("GroupPositions")]
-    public List<GroupPosition>? GroupPositions { get; set; }
+    public IEnumerable<GroupPosition>? GroupPositions { get; set; }
 
     [JsonPropertyName("Root")]
     public string? Root
@@ -75,7 +75,7 @@ public record SpawnpointTemplate
     }
 
     [JsonPropertyName("Items")]
-    public List<SptLootItem>? Items { get; set; }
+    public IEnumerable<SptLootItem>? Items { get; set; }
 }
 
 public record SptLootItem : Item
@@ -123,7 +123,7 @@ public record Spawnpoint
     public SpawnpointTemplate? Template { get; set; }
 
     [JsonPropertyName("itemDistribution")]
-    public List<LooseLootItemDistribution>? ItemDistribution { get; set; }
+    public IEnumerable<LooseLootItemDistribution>? ItemDistribution { get; set; }
 }
 
 public record LooseLootItemDistribution

Libraries/SPTarkov.Server.Core/Models/Eft/Common/Tables/Item.cs

@@ -199,7 +199,7 @@ public record LockableComponent
     [JsonExtensionData]
     public Dictionary<string, object>? ExtensionData { get; set; }
 
-    public List<string>? KeyIds { get; set; }
+    public IEnumerable<string>? KeyIds { get; set; }
     public bool? Locked { get; set; }
     public LockableKeyComponent? KeyComponent { get; set; }
 }
@@ -327,10 +327,10 @@ public record UpdSight
     public Dictionary<string, object>? ExtensionData { get; set; }
 
     [JsonPropertyName("ScopesCurrentCalibPointIndexes")]
-    public List<int>? ScopesCurrentCalibPointIndexes { get; set; }
+    public IEnumerable<int>? ScopesCurrentCalibPointIndexes { get; set; }
 
     [JsonPropertyName("ScopesSelectedModes")]
-    public List<int>? ScopesSelectedModes { get; set; }
+    public IEnumerable<int>? ScopesSelectedModes { get; set; }
 
     [JsonPropertyName("SelectedScope")]
     public int? SelectedScope { get; set; }

Libraries/SPTarkov.Server.Core/Models/Eft/Common/Tables/TemplateItem.cs

@@ -353,10 +353,10 @@ public record Props
     public bool? DogTagQualities { get; set; }
 
     [JsonPropertyName("Grids")]
-    public List<Grid>? Grids { get; set; }
+    public IEnumerable<Grid>? Grids { get; set; }
 
     [JsonPropertyName("Slots")]
-    public List<Slot>? Slots { get; set; }
+    public IEnumerable<Slot>? Slots { get; set; }
 
     [JsonPropertyName("CanPutIntoDuringTheRaid")]
     public bool? CanPutIntoDuringTheRaid { get; set; }

Libraries/SPTarkov.Server.Core/Services/BotEquipmentModPoolService.cs

@@ -89,8 +89,8 @@ public class BotEquipmentModPoolService(
                 continue;
             }
 
-            // Skip item without slots
+            // No slots
-            if (item.Properties.Slots is null || item.Properties.Slots.Count == 0)
+            if (item.Properties?.Slots is null || !item.Properties.Slots.Any())
             {
                 continue;
             }
@@ -120,7 +120,9 @@ public class BotEquipmentModPoolService(
                     }
 
                     var subItemDetails = itemHelper.GetItem(itemToAddTpl).Value;
-                    var hasSubItemsToAdd = (subItemDetails?.Properties?.Slots?.Count ?? 0) > 0;
+                    var hasSubItemsToAdd =
+                        subItemDetails.Properties?.Slots is not null
+                        && subItemDetails.Properties.Slots.Any();
 
                     // Item has Slots + pool doesn't have value
                     if (hasSubItemsToAdd && !pool.ContainsKey(subItemDetails.Id))
@@ -221,7 +223,7 @@ public class BotEquipmentModPoolService(
 
         // Get item from db
         var itemDb = itemHelper.GetItem(itemTpl).Value;
-        if (itemDb.Properties.Slots is not null)
+        if (itemDb.Properties?.Slots is not null)
         // Loop over slots flagged as 'required'
         {
             foreach (

Libraries/SPTarkov.Server.Core/Services/BotWeaponModLimitService.cs

@@ -122,7 +122,7 @@ public class BotWeaponModLimitService(
         // Mount has one slot and it is for a mod_scope
         if (
             modLimits.Scope.Count >= modLimits.ScopeMax
-            && modTemplate.Properties.Slots?.Count == 1
+            && modTemplate.Properties?.Slots?.Count() == 1
             && itemHelper.IsOfBaseclass(modTemplate.Id, BaseClasses.MOUNT)
             && !itemHelper.IsOfBaseclass(modsParent.Id, BaseClasses.MOUNT)
             && modTemplate.Properties.Slots.Any(slot => slot.Name == "mod_scope")
@@ -149,7 +149,7 @@ public class BotWeaponModLimitService(
         // Mod is a mount that can hold only flashlights ad limit is reached (don't want to add empty mounts if limit is reached)
         if (
             modLimits.Scope.Count >= modLimits.ScopeMax
-            && modTemplate.Properties.Slots?.Count == 1
+            && modTemplate.Properties?.Slots?.Count() == 1
             && itemHelper.IsOfBaseclass(modTemplate.Id, BaseClasses.MOUNT)
             && modTemplate.Properties.Slots.Any(slot => slot.Name == "mod_flashlight")
         )

Libraries/SPTarkov.Server.Core/Services/FenceService.cs

@@ -951,7 +951,8 @@ public class FenceService(
                 rootItemBeingAdded.Template,
                 [BaseClasses.ARMORED_EQUIPMENT, BaseClasses.SEARCHABLE_ITEM]
             )
-            && (itemDbDetails.Properties.Slots?.Count ?? 0) > 0;
+            && itemDbDetails?.Properties?.Slots is not null
+            && itemDbDetails.Properties.Slots.Any();
 
         // Only one match and it's not medical or armored gear
         if (matchingItems.Count == 1 && !(isMedical || isGearAndHasSlots))

Libraries/SPTarkov.Server.Core/Services/Mod/CustomItemService.cs

@@ -288,7 +288,7 @@ public class CustomItemService(
     protected void AddToWeaponShelf(string newItemId)
     {
         // Ids for wall stashes in db
-        List<string> wallStashIds =
+        List<MongoId> wallStashIds =
         [
             ItemTpl.HIDEOUTAREACONTAINER_WEAPONSTAND_STASH_1,
             ItemTpl.HIDEOUTAREACONTAINER_WEAPONSTAND_STASH_2,
@@ -299,7 +299,7 @@ public class CustomItemService(
             var wall = itemHelper.GetItem(wallId);
             if (wall.Key)
             {
-                wall.Value.Properties.Grids[0].Props.Filters[0].Filter.Add(newItemId);
+                wall.Value.Properties.Grids.First().Props.Filters[0].Filter.Add(newItemId);
             }
         }
     }

Libraries/SPTarkov.Server.Core/Services/PostDbLoadService.cs

@@ -391,18 +391,21 @@ public class PostDbLoadService(
 
                         if (existingLootPosition is not null)
                         {
-                            existingLootPosition.Template.Items.AddRange(
+                            existingLootPosition.Template.Items =
-                                positionToAdd.Template.Items
+                                existingLootPosition.Template.Items.Union(
-                            );
+                                    positionToAdd.Template.Items
-                            existingLootPosition.ItemDistribution.AddRange(
+                                );
-                                positionToAdd.ItemDistribution
+
-                            );
+                            existingLootPosition.ItemDistribution =
+                                existingLootPosition.ItemDistribution.Union(
+                                    positionToAdd.ItemDistribution
+                                );
 
                             continue;
                         }
 
                         // New position, add entire object
-                        looselootData.Spawnpoints.Add(positionToAdd);
+                        looselootData.Spawnpoints = looselootData.Spawnpoints.Append(positionToAdd);
                     }
 
                     return looselootData;

Libraries/SPTarkov.Server.Core/Services/RagfairLinkedItemService.cs

@@ -153,7 +153,7 @@ public class RagfairLinkedItemService(
         var result = new HashSet<MongoId>();
 
         var slots = item.Properties?.Slots;
-        if (slots is null || slots.Count == 0)
+        if (slots is null || !slots.Any())
         {
             // No slots, skip
             return result;

Libraries/SPTarkov.Server.Core/Services/RagfairOfferService.cs

@@ -49,7 +49,7 @@ public class RagfairOfferService(
         return ragfairOfferHolder.GetOfferById(offerId);
     }
 
-    public List<RagfairOffer>? GetOffersOfType(MongoId templateId)
+    public IEnumerable<RagfairOffer>? GetOffersOfType(MongoId templateId)
     {
         return ragfairOfferHolder.GetOffersByTemplate(templateId);
     }

Libraries/SPTarkov.Server.Core/Utils/RagfairOfferHolder.cs

@@ -68,7 +68,7 @@ public class RagfairOfferHolder(
     /// </summary>
     /// <param name="templateId">Tpl to get offers for</param>
     /// <returns>RagfairOffer list</returns>
-    public List<RagfairOffer>? GetOffersByTemplate(MongoId templateId)
+    public IEnumerable<RagfairOffer>? GetOffersByTemplate(MongoId templateId)
     {
         // Get the offerIds we want to return
         if (!_offersByTemplate.TryGetValue(templateId, out var offerIds))
@@ -76,7 +76,7 @@ public class RagfairOfferHolder(
             return null;
         }
 
-        var result = _offersById.Where(x => offerIds.Contains(x.Key)).Select(x => x.Value).ToList();
+        var result = _offersById.Where(x => offerIds.Contains(x.Key)).Select(x => x.Value);
 
         return result;
     }
@@ -86,7 +86,7 @@ public class RagfairOfferHolder(
     /// </summary>
     /// <param name="traderId">Id of trader to get offers for</param>
     /// <returns>RagfairOffer list</returns>
-    public List<RagfairOffer> GetOffersByTrader(MongoId traderId)
+    public IEnumerable<RagfairOffer> GetOffersByTrader(MongoId traderId)
     {
         if (!_offersByTrader.TryGetValue(traderId, out var offerIds))
         {
@@ -95,8 +95,7 @@ public class RagfairOfferHolder(
 
         return offerIds
             .Select(offerId => _offersById.GetValueOrDefault(offerId))
-            .Where(offer => offer != null)
+            .Where(offer => offer != null);
-            .ToList();
     }
 
     /// <summary>
@@ -117,7 +116,7 @@ public class RagfairOfferHolder(
     ///     Add a collection of offers to ragfair
     /// </summary>
     /// <param name="offers">Offers to add</param>
-    public void AddOffers(List<RagfairOffer> offers)
+    public void AddOffers(IEnumerable<RagfairOffer> offers)
     {
         foreach (var offer in offers)
         {
@@ -326,7 +325,7 @@ public class RagfairOfferHolder(
     ///     Get an array of arrays of expired offer items + children
     /// </summary>
     /// <returns>Expired offer assorts</returns>
-    public List<List<Item>> GetExpiredOfferItems()
+    public IEnumerable<List<Item>> GetExpiredOfferItems()
     {
         lock (_expiredOfferIdsLock)
         {

Tools/MongoIdTplGenerator/Generators/ItemTplMongoIdGenerator.cs

@@ -1,7 +1,6 @@
 using MongoIdTplGenerator.Utils;
 using SPTarkov.Common.Extensions;
 using SPTarkov.DI.Annotations;
-using SPTarkov.Server.Core.DI;
 using SPTarkov.Server.Core.Helpers;
 using SPTarkov.Server.Core.Models.Common;
 using SPTarkov.Server.Core.Models.Eft.Common.Tables;
@@ -498,7 +497,7 @@ public class ItemTplMongoIdGenerator(
         // Add grid size for lootable containers
         if (itemHelper.IsOfBaseclass(item.Id, BaseClasses.LOOT_CONTAINER))
         {
-            return $"{item.Properties.Grids[0]?.Props.CellsH}X{item.Properties.Grids[0]?.Props.CellsV}";
+            return $"{item.Properties.Grids.First()?.Props.CellsH}X{item.Properties.Grids.First()?.Props.CellsV}";
         }
 
         // Add ammo caliber to conflicting weapons