Fix CA1825 warnings on empty array initialisation.

OpenRA.Game/Game.cs

@@ -322,7 +322,7 @@ namespace OpenRA
 			// Special case handling of Game.Mod argument: if it matches a real filesystem path
 			// then we use this to override the mod search path, and replace it with the mod id
 			var modID = args.GetValue("Game.Mod", null);
-			var explicitModPaths = new string[0];
+			var explicitModPaths = Array.Empty<string>();
 			if (modID != null && (File.Exists(modID) || Directory.Exists(modID)))
 			{
 				explicitModPaths = new[] { modID };

OpenRA.Game/GameRules/WeaponInfo.cs

@@ -36,7 +36,7 @@ namespace OpenRA.GameRules
 	public class WarheadArgs
 	{
 		public WeaponInfo Weapon;
-		public int[] DamageModifiers = { };
+		public int[] DamageModifiers = Array.Empty<int>();
 		public WPos? Source;
 		public WRot ImpactOrientation;
 		public WPos ImpactPosition;

OpenRA.Game/Manifest.cs

@@ -80,10 +80,10 @@ namespace OpenRA
 		public readonly IReadOnlyDictionary<string, string> MapFolders;
 		public readonly MiniYaml LoadScreen;
 
-		public readonly string[] SoundFormats = { };
-		public readonly string[] SpriteFormats = { };
-		public readonly string[] PackageFormats = { };
-		public readonly string[] VideoFormats = { };
+		public readonly string[] SoundFormats = Array.Empty<string>();
+		public readonly string[] SpriteFormats = Array.Empty<string>();
+		public readonly string[] PackageFormats = Array.Empty<string>();
+		public readonly string[] VideoFormats = Array.Empty<string>();
 
 		readonly string[] reservedModuleNames =
 		{
@@ -208,7 +208,7 @@ namespace OpenRA
 		static string[] YamlList(Dictionary<string, MiniYaml> yaml, string key, bool parsePaths = false)
 		{
 			if (!yaml.ContainsKey(key))
-				return new string[] { };
+				return Array.Empty<string>();
 
 			return yaml[key].ToDictionary().Keys.ToArray();
 		}

OpenRA.Game/Map/Map.cs

@@ -270,7 +270,7 @@ namespace OpenRA
 
 				// Take the SHA1
 				if (streams.Count == 0)
-					return CryptoUtil.SHA1Hash(new byte[0]);
+					return CryptoUtil.SHA1Hash(Array.Empty<byte>());
 
 				var merged = streams[0];
 				for (var i = 1; i < streams.Count; i++)
@@ -471,7 +471,7 @@ namespace OpenRA
 			foreach (var cell in AllCells)
 			{
 				var uv = cell.ToMPos(Grid.Type);
-				cellProjection[uv] = new PPos[0];
+				cellProjection[uv] = Array.Empty<PPos>();
 				inverseCellProjection[uv] = new List<MPos>(1);
 			}
 
@@ -973,7 +973,7 @@ namespace OpenRA
 			return (PPos)CellContaining(projectedPos).ToMPos(Grid.Type);
 		}
 
-		static readonly PPos[] NoProjectedCells = { };
+		static readonly PPos[] NoProjectedCells = Array.Empty<PPos>();
 		public PPos[] ProjectedCellsCovering(MPos uv)
 		{
 			if (!initializedCellProjection)

OpenRA.Game/Map/MapPreview.cs

@@ -54,7 +54,7 @@ namespace OpenRA
 		public readonly string[] categories;
 		public readonly int players;
 		public readonly Rectangle bounds;
-		public readonly short[] spawnpoints = { };
+		public readonly short[] spawnpoints = Array.Empty<short>();
 		public readonly MapGridType map_grid_type;
 		public readonly string minimap;
 		public readonly bool downloading;
@@ -160,7 +160,7 @@ namespace OpenRA
 			}
 		}
 
-		static readonly CPos[] NoSpawns = { };
+		static readonly CPos[] NoSpawns = Array.Empty<CPos>();
 		readonly MapCache cache;
 		readonly ModData modData;
 

OpenRA.Game/Map/PlayerReference.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using OpenRA.Primitives;
 
 namespace OpenRA
@@ -53,8 +54,8 @@ namespace OpenRA
 		public bool LockHandicap = false;
 		public int Handicap = 0;
 
-		public string[] Allies = { };
-		public string[] Enemies = { };
+		public string[] Allies = Array.Empty<string>();
+		public string[] Enemies = Array.Empty<string>();
 
 		public PlayerReference() { }
 		public PlayerReference(MiniYaml my) { FieldLoader.Load(this, my); }

OpenRA.Game/ModData.cs

@@ -52,7 +52,7 @@ namespace OpenRA
 
 		public ModData(Manifest mod, InstalledMods mods, bool useLoadScreen = false)
 		{
-			Languages = new string[0];
+			Languages = Array.Empty<string>();
 
 			// Take a local copy of the manifest
 			Manifest = new Manifest(mod.Id, mod.Package);

OpenRA.Game/Network/GameSave.cs

@@ -86,7 +86,7 @@ namespace OpenRA.Network
 		// Loaded from file and updated during gameplay
 		public int LastOrdersFrame { get; private set; }
 		public int LastSyncFrame { get; private set; }
-		byte[] lastSyncPacket = new byte[0];
+		byte[] lastSyncPacket = Array.Empty<byte>();
 
 		// Loaded from file or set on game start
 		public Session.Global GlobalSettings { get; private set; }
@@ -95,7 +95,7 @@ namespace OpenRA.Network
 		public Dictionary<int, MiniYaml> TraitData = new Dictionary<int, MiniYaml>();
 
 		// Set on game start
-		int[] clientsBySlotIndex = { };
+		int[] clientsBySlotIndex = Array.Empty<int>();
 		int firstBotSlotIndex = -1;
 
 		public GameSave()

OpenRA.Game/Network/GameServer.cs

@@ -133,7 +133,7 @@ namespace OpenRA.Network
 		public readonly GameClient[] Clients;
 
 		/// <summary>The list of spawnpoints that are disabled for this game</summary>
-		public readonly int[] DisabledSpawnPoints = { };
+		public readonly int[] DisabledSpawnPoints = Array.Empty<int>();
 
 		public string ModLabel => $"{ModTitle} ({Version})";
 

OpenRA.Game/ObjectCreator.cs

@@ -141,7 +141,7 @@ namespace OpenRA
 
 		public object CreateBasic(Type type)
 		{
-			return type.GetConstructor(new Type[0]).Invoke(new object[0]);
+			return type.GetConstructor(Array.Empty<Type>()).Invoke(Array.Empty<object>());
 		}
 
 		public object CreateUsingArgs(ConstructorInfo ctor, Dictionary<string, object> args)

OpenRA.Game/SelectableExts.cs

@@ -90,7 +90,7 @@ namespace OpenRA.Traits
 			return info.SelectionPriority(modifiers) - (long)pixelDistance << 16;
 		}
 
-		static readonly Actor[] NoActors = { };
+		static readonly Actor[] NoActors = Array.Empty<Actor>();
 
 		public static IEnumerable<Actor> SubsetWithHighestSelectionPriority(this IEnumerable<Actor> actors, Modifiers modifiers)
 		{

OpenRA.Game/Settings.cs

@@ -66,16 +66,16 @@ namespace OpenRA
 		public string Map = null;
 
 		[Desc("Takes a comma separated list of IP addresses that are not allowed to join.")]
-		public string[] Ban = { };
+		public string[] Ban = Array.Empty<string>();
 
 		[Desc("For dedicated servers only, allow anonymous clients to join.")]
 		public bool RequireAuthentication = false;
 
 		[Desc("For dedicated servers only, if non-empty, only allow authenticated players with these profile IDs to join.")]
-		public int[] ProfileIDWhitelist = { };
+		public int[] ProfileIDWhitelist = Array.Empty<int>();
 
 		[Desc("For dedicated servers only, if non-empty, always reject players with these user IDs from joining.")]
-		public int[] ProfileIDBlacklist = { };
+		public int[] ProfileIDBlacklist = Array.Empty<int>();
 
 		[Desc("For dedicated servers only, controls whether a game can be started with just one human player in the lobby.")]
 		public bool EnableSingleplayer = false;
@@ -227,7 +227,7 @@ namespace OpenRA
 		public string Name = "Commander";
 		public Color Color = Color.FromArgb(200, 32, 32);
 		public string LastServer = "localhost:1234";
-		public Color[] CustomColors = { };
+		public Color[] CustomColors = Array.Empty<Color>();
 		public string Language = "en";
 	}
 

OpenRA.Game/Traits/Target.cs

@@ -18,7 +18,7 @@ namespace OpenRA.Traits
 	public enum TargetType : byte { Invalid, Actor, Terrain, FrozenActor }
 	public readonly struct Target
 	{
-		public static readonly Target[] None = { };
+		public static readonly Target[] None = Array.Empty<Target>();
 		public static readonly Target Invalid = default(Target);
 
 		readonly TargetType type;
@@ -175,7 +175,7 @@ namespace OpenRA.Traits
 		}
 
 		// Positions available to target for range checks
-		static readonly WPos[] NoPositions = { };
+		static readonly WPos[] NoPositions = Array.Empty<WPos>();
 		public IEnumerable<WPos> Positions
 		{
 			get

OpenRA.Mods.Cnc/Traits/Render/WithHarvesterSpriteBody.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using OpenRA.Mods.Common.Traits;
 using OpenRA.Mods.Common.Traits.Render;
 using OpenRA.Traits;
@@ -18,7 +19,7 @@ namespace OpenRA.Mods.Cnc.Traits.Render
 	public class WithHarvesterSpriteBodyInfo : WithFacingSpriteBodyInfo, Requires<HarvesterInfo>
 	{
 		[Desc("Images switched between depending on fullness of harvester. Overrides RenderSprites.Image.")]
-		public readonly string[] ImageByFullness = { };
+		public readonly string[] ImageByFullness = Array.Empty<string>();
 
 		public override object Create(ActorInitializer init) { return new WithHarvesterSpriteBody(init, this); }
 	}

OpenRA.Mods.Common/Activities/Transform.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.Collections.Generic;
 using OpenRA.Activities;
 using OpenRA.Mods.Common.Traits;
@@ -23,7 +24,7 @@ namespace OpenRA.Mods.Common.Activities
 		public readonly string ToActor;
 		public CVec Offset = CVec.Zero;
 		public WAngle Facing = new WAngle(384);
-		public string[] Sounds = { };
+		public string[] Sounds = Array.Empty<string>();
 		public string Notification = null;
 		public int ForceHealthPercentage = 0;
 		public bool SkipMakeAnims = false;

OpenRA.Mods.Common/AssetBrowser.cs

@@ -9,11 +9,13 @@
  */
 #endregion
 
+using System;
+
 namespace OpenRA
 {
 	public class AssetBrowser : IGlobalModData
 	{
 		[FieldLoader.Require]
-		public readonly string[] SupportedExtensions = new string[0];
+		public readonly string[] SupportedExtensions = Array.Empty<string>();
 	}
 }

OpenRA.Mods.Common/Effects/RevealShroudEffect.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using OpenRA.Effects;
@@ -19,7 +20,7 @@ namespace OpenRA.Mods.Common.Effects
 {
 	public class RevealShroudEffect : IEffect
 	{
-		static readonly PPos[] NoCells = { };
+		static readonly PPos[] NoCells = Array.Empty<PPos>();
 
 		readonly WPos pos;
 		readonly Player player;

OpenRA.Mods.Common/ModContent.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
@@ -21,8 +22,8 @@ namespace OpenRA
 		public class ModPackage
 		{
 			public readonly string Title;
-			public readonly string[] TestFiles = { };
-			public readonly string[] Sources = { };
+			public readonly string[] TestFiles = Array.Empty<string>();
+			public readonly string[] Sources = Array.Empty<string>();
 			public readonly bool Required;
 			public readonly string Download;
 
@@ -106,21 +107,21 @@ namespace OpenRA
 		}
 
 		[FieldLoader.LoadUsing(nameof(LoadDownloads))]
-		public readonly string[] Downloads = { };
+		public readonly string[] Downloads = Array.Empty<string>();
 
 		static object LoadDownloads(MiniYaml yaml)
 		{
 			var downloadNode = yaml.Nodes.FirstOrDefault(n => n.Key == "Downloads");
-			return downloadNode != null ? downloadNode.Value.Nodes.Select(n => n.Key).ToArray() : new string[0];
+			return downloadNode != null ? downloadNode.Value.Nodes.Select(n => n.Key).ToArray() : Array.Empty<string>();
 		}
 
 		[FieldLoader.LoadUsing(nameof(LoadSources))]
-		public readonly string[] Sources = { };
+		public readonly string[] Sources = Array.Empty<string>();
 
 		static object LoadSources(MiniYaml yaml)
 		{
 			var sourceNode = yaml.Nodes.FirstOrDefault(n => n.Key == "Sources");
-			return sourceNode != null ? sourceNode.Value.Nodes.Select(n => n.Key).ToArray() : new string[0];
+			return sourceNode != null ? sourceNode.Value.Nodes.Select(n => n.Key).ToArray() : Array.Empty<string>();
 		}
 	}
 }

OpenRA.Mods.Common/Traits/AcceptsDeliveredCash.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.Collections.Generic;
 using OpenRA.Traits;
 
@@ -24,16 +25,16 @@ namespace OpenRA.Mods.Common.Traits
 		public readonly PlayerRelationship ValidRelationships = PlayerRelationship.Ally;
 
 		[Desc("Play a randomly selected sound from this list when accepting cash.")]
-		public readonly string[] Sounds = { };
+		public readonly string[] Sounds = Array.Empty<string>();
 
-		public override object Create(ActorInitializer init) { return new AcceptsDeliveredCash(init.Self, this); }
+		public override object Create(ActorInitializer init) { return new AcceptsDeliveredCash(this); }
 	}
 
 	public class AcceptsDeliveredCash : INotifyCashTransfer
 	{
 		readonly AcceptsDeliveredCashInfo info;
 
-		public AcceptsDeliveredCash(Actor self, AcceptsDeliveredCashInfo info)
+		public AcceptsDeliveredCash(AcceptsDeliveredCashInfo info)
 		{
 			this.info = info;
 		}

OpenRA.Mods.Common/Traits/AffectsShroud.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using OpenRA.Traits;
@@ -35,7 +36,7 @@ namespace OpenRA.Mods.Common.Traits
 	public abstract class AffectsShroud : ConditionalTrait<AffectsShroudInfo>, ISync, INotifyAddedToWorld,
 		INotifyRemovedFromWorld, INotifyMoving, INotifyCenterPositionChanged, ITick
 	{
-		static readonly PPos[] NoCells = { };
+		static readonly PPos[] NoCells = Array.Empty<PPos>();
 
 		readonly HashSet<PPos> footprint;
 

OpenRA.Mods.Common/Traits/Air/Aircraft.cs

@@ -139,10 +139,10 @@ namespace OpenRA.Mods.Common.Traits
 		public readonly WDist AltitudeVelocity = new WDist(43);
 
 		[Desc("Sounds to play when the actor is taking off.")]
-		public readonly string[] TakeoffSounds = { };
+		public readonly string[] TakeoffSounds = Array.Empty<string>();
 
 		[Desc("Sounds to play when the actor is landing.")]
-		public readonly string[] LandingSounds = { };
+		public readonly string[] LandingSounds = Array.Empty<string>();
 
 		[Desc("The distance of the resupply base that the aircraft will wait for its turn.")]
 		public readonly WDist WaitDistanceFromResupplyBase = new WDist(3072);

OpenRA.Mods.Common/Traits/Armament.cs

@@ -41,10 +41,10 @@ namespace OpenRA.Mods.Common.Traits
 
 		[Desc("Muzzle position relative to turret or body, (forward, right, up) triples.",
 			"If weapon Burst = 1, it cycles through all listed offsets, otherwise the offset corresponding to current burst is used.")]
-		public readonly WVec[] LocalOffset = { };
+		public readonly WVec[] LocalOffset = Array.Empty<WVec>();
 
 		[Desc("Muzzle yaw relative to turret or body.")]
-		public readonly WAngle[] LocalYaw = { };
+		public readonly WAngle[] LocalYaw = Array.Empty<WAngle>();
 
 		[Desc("Move the turret backwards when firing.")]
 		public readonly WDist Recoil = WDist.Zero;

OpenRA.Mods.Common/Traits/Buildable.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.Collections.Generic;
 using OpenRA.Traits;
 
@@ -20,7 +21,7 @@ namespace OpenRA.Mods.Common.Traits
 			"This can be prefixed with ! to invert the prerequisite (disabling production if the prerequisite is available)",
 			"and/or ~ to hide the actor from the production palette if the prerequisite is not available.",
 			"Prerequisites are granted by actors with the ProvidesPrerequisite trait.")]
-		public readonly string[] Prerequisites = { };
+		public readonly string[] Prerequisites = Array.Empty<string>();
 
 		[Desc("Production queue(s) that can produce this.")]
 		public readonly HashSet<string> Queue = new HashSet<string>();

OpenRA.Mods.Common/Traits/Buildings/BridgeHut.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using OpenRA.Effects;
@@ -24,7 +25,7 @@ namespace OpenRA.Mods.Common.Traits
 		public readonly string[] Types = { "GroundLevelBridge" };
 
 		[Desc("Offsets to look for adjacent bridges to act on")]
-		public readonly CVec[] NeighbourOffsets = { };
+		public readonly CVec[] NeighbourOffsets = Array.Empty<CVec>();
 
 		[Desc("Delay between each segment repair step")]
 		public readonly int RepairPropagationDelay = 20;

OpenRA.Mods.Common/Traits/Buildings/BridgePlaceholder.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using OpenRA.Primitives;
 using OpenRA.Traits;
 
@@ -25,7 +26,7 @@ namespace OpenRA.Mods.Common.Traits
 		[Desc("Actor type to replace with on repair.")]
 		public readonly string ReplaceWithActor = null;
 
-		public readonly CVec[] NeighbourOffsets = { };
+		public readonly CVec[] NeighbourOffsets = Array.Empty<CVec>();
 
 		public override object Create(ActorInitializer init) { return new BridgePlaceholder(init.Self, this); }
 	}

OpenRA.Mods.Common/Traits/Buildings/Building.cs

@@ -56,9 +56,9 @@ namespace OpenRA.Mods.Common.Traits
 		[Desc("Clear smudges from underneath the building footprint on transform.")]
 		public readonly bool RemoveSmudgesOnTransform = true;
 
-		public readonly string[] BuildSounds = { };
+		public readonly string[] BuildSounds = Array.Empty<string>();
 
-		public readonly string[] UndeploySounds = { };
+		public readonly string[] UndeploySounds = Array.Empty<string>();
 
 		public override object Create(ActorInitializer init) { return new Building(init, this); }
 

OpenRA.Mods.Common/Traits/Buildings/GroundLevelBridge.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.Collections.Generic;
 using OpenRA.GameRules;
 using OpenRA.Primitives;
@@ -23,7 +24,7 @@ namespace OpenRA.Mods.Common.Traits
 
 		public readonly string Type = "GroundLevelBridge";
 
-		public readonly CVec[] NeighbourOffsets = { };
+		public readonly CVec[] NeighbourOffsets = Array.Empty<CVec>();
 
 		[WeaponReference]
 		[Desc("The name of the weapon to use when demolishing the bridge")]

OpenRA.Mods.Common/Traits/Buildings/PrimaryBuilding.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using OpenRA.Mods.Common.Orders;
@@ -38,7 +39,7 @@ namespace OpenRA.Mods.Common.Traits
 
 		[Desc("List of production queues for which the primary flag should be set.",
 			"If empty, the list given in the `Produces` property of the `" + nameof(Production) + "` trait will be used.")]
-		public readonly string[] ProductionQueues = { };
+		public readonly string[] ProductionQueues = Array.Empty<string>();
 
 		[CursorReference]
 		[Desc("Cursor to display when setting the primary building.")]

OpenRA.Mods.Common/Traits/Buildings/RallyPoint.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using OpenRA.Mods.Common.Effects;
@@ -42,7 +43,7 @@ namespace OpenRA.Mods.Common.Traits
 		public readonly bool IsPlayerPalette = true;
 
 		[Desc("A list of 0 or more offsets defining the initial rally point path.")]
-		public readonly CVec[] Path = { };
+		public readonly CVec[] Path = Array.Empty<CVec>();
 
 		[NotificationReference("Speech")]
 		[Desc("The speech notification to play when setting a new rallypoint.")]

OpenRA.Mods.Common/Traits/Cargo.cs

@@ -30,7 +30,7 @@ namespace OpenRA.Mods.Common.Traits
 		public readonly HashSet<string> Types = new HashSet<string>();
 
 		[Desc("A list of actor types that are initially spawned into this actor.")]
-		public readonly string[] InitialUnits = { };
+		public readonly string[] InitialUnits = Array.Empty<string>();
 
 		[Desc("When this actor is sold should all of its passengers be unloaded?")]
 		public readonly bool EjectOnSell = true;

OpenRA.Mods.Common/Traits/Conditions/GrantConditionOnBotOwner.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.Linq;
 using OpenRA.Traits;
 
@@ -24,7 +25,7 @@ namespace OpenRA.Mods.Common.Traits
 
 		[FieldLoader.Require]
 		[Desc("Bot types that trigger the condition.")]
-		public readonly string[] Bots = { };
+		public readonly string[] Bots = Array.Empty<string>();
 
 		public override object Create(ActorInitializer init) { return new GrantConditionOnBotOwner(init, this); }
 	}

OpenRA.Mods.Common/Traits/Conditions/GrantConditionOnDamageState.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using OpenRA.Traits;
 
 namespace OpenRA.Mods.Common.Traits
@@ -22,10 +23,10 @@ namespace OpenRA.Mods.Common.Traits
 		public readonly string Condition = null;
 
 		[Desc("Play a random sound from this list when enabled.")]
-		public readonly string[] EnabledSounds = { };
+		public readonly string[] EnabledSounds = Array.Empty<string>();
 
 		[Desc("Play a random sound from this list when disabled.")]
-		public readonly string[] DisabledSounds = { };
+		public readonly string[] DisabledSounds = Array.Empty<string>();
 
 		[Desc("Levels of damage at which to grant the condition.")]
 		public readonly DamageState ValidDamageStates = DamageState.Heavy | DamageState.Critical;

OpenRA.Mods.Common/Traits/Conditions/GrantConditionOnHealth.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using OpenRA.Traits;
 
 namespace OpenRA.Mods.Common.Traits
@@ -22,10 +23,10 @@ namespace OpenRA.Mods.Common.Traits
 		public readonly string Condition = null;
 
 		[Desc("Play a random sound from this list when enabled.")]
-		public readonly string[] EnabledSounds = { };
+		public readonly string[] EnabledSounds = Array.Empty<string>();
 
 		[Desc("Play a random sound from this list when disabled.")]
-		public readonly string[] DisabledSounds = { };
+		public readonly string[] DisabledSounds = Array.Empty<string>();
 
 		[Desc("Minimum level of health at which to grant the condition.")]
 		public readonly int MinHP = 0;

OpenRA.Mods.Common/Traits/Conditions/GrantConditionOnPrerequisite.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.Linq;
 using OpenRA.Traits;
 
@@ -24,7 +25,7 @@ namespace OpenRA.Mods.Common.Traits
 
 		[FieldLoader.Require]
 		[Desc("List of required prerequisites.")]
-		public readonly string[] Prerequisites = { };
+		public readonly string[] Prerequisites = Array.Empty<string>();
 
 		public override object Create(ActorInitializer init) { return new GrantConditionOnPrerequisite(init.Self, this); }
 	}

OpenRA.Mods.Common/Traits/Conditions/GrantConditionOnTerrain.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.Linq;
 using OpenRA.Traits;
 
@@ -23,7 +24,7 @@ namespace OpenRA.Mods.Common.Traits
 
 		[FieldLoader.Require]
 		[Desc("Terrain names to trigger the condition.")]
-		public readonly string[] TerrainTypes = { };
+		public readonly string[] TerrainTypes = Array.Empty<string>();
 
 		public override object Create(ActorInitializer init) { return new GrantConditionOnTerrain(init, this); }
 	}

OpenRA.Mods.Common/Traits/Conditions/GrantConditionOnTileSet.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.Linq;
 using OpenRA.Traits;
 
@@ -23,7 +24,7 @@ namespace OpenRA.Mods.Common.Traits
 
 		[FieldLoader.Require]
 		[Desc("Tile set IDs to trigger the condition.")]
-		public readonly string[] TileSets = { };
+		public readonly string[] TileSets = Array.Empty<string>();
 
 		public override object Create(ActorInitializer init) { return new GrantConditionOnTileSet(this); }
 	}

OpenRA.Mods.Common/Traits/Crates/CrateAction.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.Linq;
 using OpenRA.Mods.Common.Effects;
 using OpenRA.Traits;
@@ -42,11 +43,11 @@ namespace OpenRA.Mods.Common.Traits
 		public readonly int TimeDelay = 0;
 
 		[Desc("Only allow this crate action when the collector has these prerequisites")]
-		public readonly string[] Prerequisites = { };
+		public readonly string[] Prerequisites = Array.Empty<string>();
 
 		[ActorReference]
 		[Desc("Actor types that this crate action will not occur for.")]
-		public string[] ExcludedActorTypes = { };
+		public string[] ExcludedActorTypes = Array.Empty<string>();
 
 		public override object Create(ActorInitializer init) { return new CrateAction(init.Self, this); }
 	}

OpenRA.Mods.Common/Traits/Crates/GiveUnitCrateAction.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using OpenRA.Primitives;
@@ -22,7 +23,7 @@ namespace OpenRA.Mods.Common.Traits
 		[ActorReference]
 		[FieldLoader.Require]
 		[Desc("The list of units to spawn.")]
-		public readonly string[] Units = { };
+		public readonly string[] Units = Array.Empty<string>();
 
 		[Desc("Factions that are allowed to trigger this action.")]
 		public readonly HashSet<string> ValidFactions = new HashSet<string>();

OpenRA.Mods.Common/Traits/DamagedByTerrain.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.Linq;
 using OpenRA.Primitives;
 using OpenRA.Traits;
@@ -30,7 +31,7 @@ namespace OpenRA.Mods.Common.Traits
 
 		[FieldLoader.Require]
 		[Desc("Terrain types where the actor will take damage.")]
-		public readonly string[] Terrain = { };
+		public readonly string[] Terrain = Array.Empty<string>();
 
 		public override object Create(ActorInitializer init) { return new DamagedByTerrain(this); }
 	}

OpenRA.Mods.Common/Traits/DeliversCash.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.Collections.Generic;
 using OpenRA.Mods.Common.Activities;
 using OpenRA.Mods.Common.Orders;
@@ -30,7 +31,7 @@ namespace OpenRA.Mods.Common.Traits
 		public readonly string Type = null;
 
 		[Desc("Sound to play when delivering cash")]
-		public readonly string[] Sounds = { };
+		public readonly string[] Sounds = Array.Empty<string>();
 
 		[CursorReference]
 		[Desc("Cursor to display when hovering over a valid actor to deliver cash to.")]

OpenRA.Mods.Common/Traits/Multipliers/ProductionCostMultiplier.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using OpenRA.Traits;
@@ -22,7 +23,7 @@ namespace OpenRA.Mods.Common.Traits
 		public readonly int Multiplier = 100;
 
 		[Desc("Only apply this cost change if owner has these prerequisites.")]
-		public readonly string[] Prerequisites = { };
+		public readonly string[] Prerequisites = Array.Empty<string>();
 
 		[Desc("Queues that this cost will apply.")]
 		public readonly HashSet<string> Queue = new HashSet<string>();

OpenRA.Mods.Common/Traits/Multipliers/ProductionTimeMultiplier.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using OpenRA.Traits;
@@ -22,7 +23,7 @@ namespace OpenRA.Mods.Common.Traits
 		public readonly int Multiplier = 100;
 
 		[Desc("Only apply this time change if owner has these prerequisites.")]
-		public readonly string[] Prerequisites = { };
+		public readonly string[] Prerequisites = Array.Empty<string>();
 
 		[Desc("Queues that this time will apply.")]
 		public readonly HashSet<string> Queue = new HashSet<string>();

OpenRA.Mods.Common/Traits/Palettes/ColorPickerPalette.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.Collections.Generic;
 using OpenRA.Graphics;
 using OpenRA.Primitives;
@@ -32,7 +33,7 @@ namespace OpenRA.Mods.Common.Traits
 
 		[FieldLoader.Require]
 		[Desc("Remap these indices to player colors.")]
-		public readonly int[] RemapIndex = { };
+		public readonly int[] RemapIndex = Array.Empty<int>();
 
 		[Desc("Allow palette modifiers to change the palette.")]
 		public readonly bool AllowModifiers = true;

OpenRA.Mods.Common/Traits/Palettes/FixedColorPalette.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using OpenRA.Graphics;
 using OpenRA.Primitives;
 using OpenRA.Traits;
@@ -28,7 +29,7 @@ namespace OpenRA.Mods.Common.Traits
 		public readonly string Name = "resources";
 
 		[Desc("Remap these indices to pre-defined colors.")]
-		public readonly int[] RemapIndex = { };
+		public readonly int[] RemapIndex = Array.Empty<int>();
 
 		[Desc("The fixed color to remap.")]
 		public readonly Color Color;

OpenRA.Mods.Common/Traits/Palettes/IndexedPalette.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.Collections.Generic;
 using System.IO;
 using OpenRA.Graphics;
@@ -32,11 +33,11 @@ namespace OpenRA.Mods.Common.Traits
 
 		[FieldLoader.Require]
 		[Desc("Indices from BasePalette to be swapped with ReplaceIndex.")]
-		public readonly int[] Index = { };
+		public readonly int[] Index = Array.Empty<int>();
 
 		[FieldLoader.Require]
 		[Desc("Indices from BasePalette to replace from Index.")]
-		public readonly int[] ReplaceIndex = { };
+		public readonly int[] ReplaceIndex = Array.Empty<int>();
 
 		[Desc("Allow palette modifiers to change the palette.")]
 		public readonly bool AllowModifiers = true;

OpenRA.Mods.Common/Traits/Palettes/IndexedPlayerPalette.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.Collections.Generic;
 using OpenRA.Graphics;
 using OpenRA.Primitives;
@@ -29,7 +30,7 @@ namespace OpenRA.Mods.Common.Traits
 		public readonly string BaseName = "player";
 
 		[Desc("Remap these indices to player colors.")]
-		public readonly int[] RemapIndex = { };
+		public readonly int[] RemapIndex = Array.Empty<int>();
 
 		[Desc("Allow palette modifiers to change the palette.")]
 		public readonly bool AllowModifiers = true;

OpenRA.Mods.Common/Traits/Palettes/PaletteFromFile.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.Collections.Generic;
 using OpenRA.FileSystem;
 using OpenRA.Graphics;
@@ -36,7 +37,7 @@ namespace OpenRA.Mods.Common.Traits
 		public readonly int[] TransparentIndex = { 0 };
 
 		[Desc("Map listed indices to shadow. Ignores previous color.")]
-		public readonly int[] ShadowIndex = { };
+		public readonly int[] ShadowIndex = Array.Empty<int>();
 
 		public readonly bool AllowModifiers = true;
 

OpenRA.Mods.Common/Traits/Palettes/PaletteFromPng.cs

@@ -35,7 +35,7 @@ namespace OpenRA.Mods.Common.Traits
 		public readonly string Filename = null;
 
 		[Desc("Map listed indices to shadow. Ignores previous color.")]
-		public readonly int[] ShadowIndex = { };
+		public readonly int[] ShadowIndex = Array.Empty<int>();
 
 		public readonly bool AllowModifiers = true;
 

OpenRA.Mods.Common/Traits/Palettes/PlayerColorPalette.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using OpenRA.Graphics;
 using OpenRA.Primitives;
 using OpenRA.Traits;
@@ -28,7 +29,7 @@ namespace OpenRA.Mods.Common.Traits
 		public readonly string BaseName = "player";
 
 		[Desc("Remap these indices to player colors.")]
-		public readonly int[] RemapIndex = { };
+		public readonly int[] RemapIndex = Array.Empty<int>();
 
 		[Desc("Allow palette modifiers to change the palette.")]
 		public readonly bool AllowModifiers = true;

OpenRA.Mods.Common/Traits/Player/ClassicParallelProductionQueue.cs

@@ -40,7 +40,7 @@ namespace OpenRA.Mods.Common.Traits
 
 	public class ClassicParallelProductionQueue : ProductionQueue
 	{
-		static readonly ActorInfo[] NoItems = { };
+		static readonly ActorInfo[] NoItems = Array.Empty<ActorInfo>();
 
 		readonly Actor self;
 		readonly ClassicParallelProductionQueueInfo info;

OpenRA.Mods.Common/Traits/Player/ClassicProductionQueue.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using OpenRA.Primitives;
@@ -35,7 +36,7 @@ namespace OpenRA.Mods.Common.Traits
 
 	public class ClassicProductionQueue : ProductionQueue
 	{
-		static readonly ActorInfo[] NoItems = { };
+		static readonly ActorInfo[] NoItems = Array.Empty<ActorInfo>();
 
 		readonly Actor self;
 		readonly ClassicProductionQueueInfo info;

OpenRA.Mods.Common/Traits/Player/ProvidesPrerequisite.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using OpenRA.Traits;
@@ -21,7 +22,7 @@ namespace OpenRA.Mods.Common.Traits
 		public readonly string Prerequisite = null;
 
 		[Desc("Only grant this prerequisite when you have these prerequisites.")]
-		public readonly string[] RequiresPrerequisites = { };
+		public readonly string[] RequiresPrerequisites = Array.Empty<string>();
 
 		[Desc("Only grant this prerequisite for certain factions.")]
 		public readonly HashSet<string> Factions = new HashSet<string>();

OpenRA.Mods.Common/Traits/Player/ProvidesTechPrerequisite.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.Collections.Generic;
 using OpenRA.Traits;
 
@@ -24,7 +25,7 @@ namespace OpenRA.Mods.Common.Traits
 		public readonly string Name;
 
 		[Desc("Prerequisites to grant when this tech level is active.")]
-		public readonly string[] Prerequisites = { };
+		public readonly string[] Prerequisites = Array.Empty<string>();
 
 		IEnumerable<string> ITechTreePrerequisiteInfo.Prerequisites(ActorInfo info) { return Prerequisites; }
 
@@ -36,7 +37,7 @@ namespace OpenRA.Mods.Common.Traits
 		readonly ProvidesTechPrerequisiteInfo info;
 		bool enabled;
 
-		static readonly string[] NoPrerequisites = new string[0];
+		static readonly string[] NoPrerequisites = Array.Empty<string>();
 
 		public string Name => info.Name;
 

OpenRA.Mods.Common/Traits/ProducibleWithLevel.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using OpenRA.Traits;
 
 namespace OpenRA.Mods.Common.Traits
@@ -18,7 +19,7 @@ namespace OpenRA.Mods.Common.Traits
 		"trait, the production queue icon renders with an overlay defined in that trait.")]
 	public class ProducibleWithLevelInfo : TraitInfo, Requires<GainsExperienceInfo>
 	{
-		public readonly string[] Prerequisites = { };
+		public readonly string[] Prerequisites = Array.Empty<string>();
 
 		[Desc("Number of levels to give to the actor on creation.")]
 		public readonly int InitialLevels = 1;

OpenRA.Mods.Common/Traits/Production.cs

@@ -22,7 +22,7 @@ namespace OpenRA.Mods.Common.Traits
 	{
 		[FieldLoader.Require]
 		[Desc("e.g. Infantry, Vehicles, Aircraft, Buildings")]
-		public readonly string[] Produces = { };
+		public readonly string[] Produces = Array.Empty<string>();
 
 		public override object Create(ActorInitializer init) { return new Production(init, this); }
 	}

OpenRA.Mods.Common/Traits/Render/WithAmmoPipsDecoration.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using OpenRA.Graphics;
@@ -39,7 +40,7 @@ namespace OpenRA.Mods.Common.Traits.Render
 		public readonly string Palette = "chrome";
 
 		[Desc("Name(s) of AmmoPool(s) that use this decoration. Leave empty to include all pools.")]
-		public readonly string[] AmmoPools = { };
+		public readonly string[] AmmoPools = Array.Empty<string>();
 
 		public override object Create(ActorInitializer init) { return new WithAmmoPipsDecoration(init.Self, this); }
 	}

OpenRA.Mods.Common/Traits/Render/WithCrateBody.cs

@@ -22,7 +22,7 @@ namespace OpenRA.Mods.Common.Traits.Render
 	class WithCrateBodyInfo : TraitInfo, Requires<RenderSpritesInfo>, IRenderActorPreviewSpritesInfo
 	{
 		[Desc("Easteregg sequences to use in December.")]
-		public readonly string[] XmasImages = { };
+		public readonly string[] XmasImages = Array.Empty<string>();
 
 		[Desc("Terrain types on which to display WaterSequence.")]
 		public readonly HashSet<string> WaterTerrainTypes = new HashSet<string> { "Water" };

OpenRA.Mods.Common/Traits/Render/WithDeadBridgeSpriteBody.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using OpenRA.Graphics;
@@ -20,7 +21,7 @@ namespace OpenRA.Mods.Common.Traits.Render
 	class WithDeadBridgeSpriteBodyInfo : WithSpriteBodyInfo
 	{
 		[ActorReference]
-		public readonly string[] RampActors = { };
+		public readonly string[] RampActors = Array.Empty<string>();
 
 		[Desc("Offset to search for the 'A' neighbour")]
 		public readonly CVec AOffset = CVec.Zero;

OpenRA.Mods.Common/Traits/Render/WithDecorationBase.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using OpenRA.Graphics;
@@ -41,7 +42,7 @@ namespace OpenRA.Mods.Common.Traits.Render
 		public readonly int BlinkInterval = 5;
 
 		[Desc("A pattern of ticks (BlinkInterval long) where the decoration is visible or hidden.")]
-		public readonly BlinkState[] BlinkPattern = { };
+		public readonly BlinkState[] BlinkPattern = Array.Empty<BlinkState>();
 
 		[Desc("Override blink conditions to use when defined conditions are enabled.",
 			"A dictionary of [condition string]: [pattern].")]

OpenRA.Mods.Common/Traits/Render/WithGateSpriteBody.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using OpenRA.Graphics;
@@ -20,7 +21,7 @@ namespace OpenRA.Mods.Common.Traits.Render
 	class WithGateSpriteBodyInfo : WithSpriteBodyInfo, IWallConnectorInfo, Requires<GateInfo>
 	{
 		[Desc("Cells (outside the gate footprint) that contain wall cells that can connect to the gate")]
-		public readonly CVec[] WallConnections = { };
+		public readonly CVec[] WallConnections = Array.Empty<CVec>();
 
 		[Desc("Wall type for connections")]
 		public readonly string Type = "wall";

OpenRA.Mods.Common/Traits/Render/WithInfantryBody.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using OpenRA.Graphics;
@@ -35,7 +36,7 @@ namespace OpenRA.Mods.Common.Traits.Render
 		public readonly Dictionary<string, string[]> AttackSequences = new Dictionary<string, string[]>();
 
 		[SequenceReference]
-		public readonly string[] IdleSequences = { };
+		public readonly string[] IdleSequences = Array.Empty<string>();
 
 		[SequenceReference]
 		public readonly string[] StandSequences = { "stand" };

OpenRA.Mods.Common/Traits/Sellable.cs

@@ -24,7 +24,7 @@ namespace OpenRA.Mods.Common.Traits
 		public readonly int RefundPercent = 50;
 
 		[Desc("List of audio clips to play when the actor is being sold.")]
-		public readonly string[] SellSounds = { };
+		public readonly string[] SellSounds = Array.Empty<string>();
 
 		[NotificationReference("Speech")]
 		[Desc("The audio notification type to play.")]

OpenRA.Mods.Common/Traits/Sound/AttackSounds.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.Linq;
 using OpenRA.Traits;
 
@@ -18,7 +19,7 @@ namespace OpenRA.Mods.Common.Traits.Sound
 	public class AttackSoundsInfo : ConditionalTraitInfo
 	{
 		[Desc("Play a randomly selected sound from this list when preparing for an attack or attacking.")]
-		public readonly string[] Sounds = { };
+		public readonly string[] Sounds = Array.Empty<string>();
 
 		[Desc("Delay in ticks before sound starts, either relative to attack preparation or attack.")]
 		public readonly int Delay = 0;

OpenRA.Mods.Common/Traits/Sound/SoundOnDamageTransition.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using OpenRA.Primitives;
 using OpenRA.Traits;
 
@@ -17,10 +18,10 @@ namespace OpenRA.Mods.Common.Traits.Sound
 	public class SoundOnDamageTransitionInfo : TraitInfo
 	{
 		[Desc("Play a random sound from this list when damaged.")]
-		public readonly string[] DamagedSounds = { };
+		public readonly string[] DamagedSounds = Array.Empty<string>();
 
 		[Desc("Play a random sound from this list when destroyed.")]
-		public readonly string[] DestroyedSounds = { };
+		public readonly string[] DestroyedSounds = Array.Empty<string>();
 
 		[Desc("DamageType(s) that trigger the sounds. Leave empty to always trigger a sound.")]
 		public readonly BitSet<DamageType> DamageTypes = default(BitSet<DamageType>);

OpenRA.Mods.Common/Traits/SupportPowers/NukePower.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using OpenRA.GameRules;
@@ -61,7 +62,7 @@ namespace OpenRA.Mods.Common.Traits
 
 		[SequenceReference(nameof(TrailImage), allowNullImage: true)]
 		[Desc("Loop a randomly chosen sequence of TrailImage from this list while this projectile is moving.")]
-		public readonly string[] TrailSequences = { };
+		public readonly string[] TrailSequences = Array.Empty<string>();
 
 		[Desc("Interval in ticks between each spawned Trail animation.")]
 		public readonly int TrailInterval = 1;

OpenRA.Mods.Common/Traits/SupportPowers/ParatroopersPower.cs

@@ -38,7 +38,7 @@ namespace OpenRA.Mods.Common.Traits
 
 		[ActorReference(typeof(PassengerInfo))]
 		[Desc("Troops to be delivered.  They will be distributed between the planes if SquadSize > 1.")]
-		public readonly string[] DropItems = { };
+		public readonly string[] DropItems = Array.Empty<string>();
 
 		[Desc("Risks stuck units when they don't have the Paratrooper trait.")]
 		public readonly bool AllowImpassableCells = false;

OpenRA.Mods.Common/Traits/SupportPowers/SupportPower.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.Collections.Generic;
 using OpenRA.Traits;
 
@@ -45,7 +46,7 @@ namespace OpenRA.Mods.Common.Traits
 		[Desc("If set to true, the support power will be fully charged when it becomes available. " +
 			"Normal rules apply for subsequent charges.")]
 		public readonly bool StartFullyCharged = false;
-		public readonly string[] Prerequisites = { };
+		public readonly string[] Prerequisites = Array.Empty<string>();
 
 		public readonly string DetectedSound = null;
 

OpenRA.Mods.Common/Traits/SupportPowers/SupportPowerManager.cs

@@ -106,7 +106,7 @@ namespace OpenRA.Mods.Common.Traits
 				Powers[order.OrderString].Activate(order);
 		}
 
-		static readonly SupportPowerInstance[] NoInstances = { };
+		static readonly SupportPowerInstance[] NoInstances = Array.Empty<SupportPowerInstance>();
 
 		public IEnumerable<SupportPowerInstance> GetPowersForActor(Actor a)
 		{

OpenRA.Mods.Common/Traits/ThrowsShrapnel.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.Linq;
 using OpenRA.GameRules;
 using OpenRA.Traits;
@@ -21,7 +22,7 @@ namespace OpenRA.Mods.Common.Traits
 		[WeaponReference]
 		[FieldLoader.Require]
 		[Desc("The weapons used for shrapnel.")]
-		public readonly string[] Weapons = { };
+		public readonly string[] Weapons = Array.Empty<string>();
 
 		[Desc("The amount of pieces of shrapnel to expel. Two values indicate a range.")]
 		public readonly int[] Pieces = { 3, 10 };

OpenRA.Mods.Common/Traits/Transforms.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.Collections.Generic;
 using OpenRA.Activities;
 using OpenRA.Mods.Common.Activities;
@@ -32,10 +33,10 @@ namespace OpenRA.Mods.Common.Traits
 		public readonly WAngle Facing = new WAngle(384);
 
 		[Desc("Sounds to play when transforming.")]
-		public readonly string[] TransformSounds = { };
+		public readonly string[] TransformSounds = Array.Empty<string>();
 
 		[Desc("Sounds to play when the transformation is blocked.")]
-		public readonly string[] NoTransformSounds = { };
+		public readonly string[] NoTransformSounds = Array.Empty<string>();
 
 		[NotificationReference("Speech")]
 		[Desc("Notification to play when transforming.")]

OpenRA.Mods.Common/Traits/World/ActorSpawnManager.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using OpenRA.Primitives;
@@ -32,7 +33,7 @@ namespace OpenRA.Mods.Common.Traits
 		[FieldLoader.Require]
 		[ActorReference]
 		[Desc("Name of the actor that will be randomly picked to spawn.")]
-		public readonly string[] Actors = { };
+		public readonly string[] Actors = Array.Empty<string>();
 
 		public readonly string Owner = "Creeps";
 

OpenRA.Mods.Common/Traits/World/ColorPickerManager.cs

@@ -32,10 +32,10 @@ namespace OpenRA.Mods.Common.Traits
 		public readonly float SimilarityThreshold = 0.314f;
 
 		[Desc("List of hue components for the preset colors in the palette tab. Each entry must have a corresponding PresetSaturations definition.")]
-		public readonly float[] PresetHues = { };
+		public readonly float[] PresetHues = Array.Empty<float>();
 
 		[Desc("List of saturation components for the preset colors in the palette tab. Each entry must have a corresponding PresetHues definition.")]
-		public readonly float[] PresetSaturations = { };
+		public readonly float[] PresetSaturations = Array.Empty<float>();
 
 		[ActorReference]
 		[Desc("Actor type to show in the color picker. This can be overridden for specific factions with FactionPreviewActors.")]

OpenRA.Mods.Common/Traits/World/MapStartingUnits.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.Collections.Generic;
 using OpenRA.Traits;
 
@@ -36,7 +37,7 @@ namespace OpenRA.Mods.Common.Traits
 
 		[Desc("A group of units ready to defend or scout.")]
 		[ActorReference]
-		public readonly string[] SupportActors = { };
+		public readonly string[] SupportActors = Array.Empty<string>();
 
 		[Desc("Inner radius for spawning support actors")]
 		public readonly int InnerSupportRadius = 2;

OpenRA.Mods.Common/Traits/World/ResourceRenderer.cs

@@ -31,7 +31,7 @@ namespace OpenRA.Mods.Common.Traits
 			[FieldLoader.Require]
 			[SequenceReference(nameof(Image))]
 			[Desc("Randomly chosen image sequences.")]
-			public readonly string[] Sequences = { };
+			public readonly string[] Sequences = Array.Empty<string>();
 
 			[PaletteReference]
 			[Desc("Palette used for rendering the resource sprites.")]

OpenRA.Mods.Common/Traits/World/SmudgeLayer.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
@@ -42,7 +43,7 @@ namespace OpenRA.Mods.Common.Traits
 
 		[SequenceReference(nameof(SmokeImage))]
 		[Desc("Smoke sprite sequences randomly chosen from")]
-		public readonly string[] SmokeSequences = { };
+		public readonly string[] SmokeSequences = Array.Empty<string>();
 
 		[PaletteReference]
 		public readonly string SmokePalette = "effect";

OpenRA.Mods.Common/Warheads/CreateEffectWarhead.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.Linq;
 using OpenRA.GameRules;
 using OpenRA.Mods.Common.Effects;
@@ -22,7 +23,7 @@ namespace OpenRA.Mods.Common.Warheads
 	{
 		[SequenceReference(nameof(Image), allowNullImage: true)]
 		[Desc("List of explosion sequences that can be used.")]
-		public readonly string[] Explosions = new string[0];
+		public readonly string[] Explosions = Array.Empty<string>();
 
 		[Desc("Image containing explosion effect sequence.")]
 		public readonly string Image = "explosion";
@@ -38,7 +39,7 @@ namespace OpenRA.Mods.Common.Warheads
 		public readonly bool ForceDisplayAtGroundLevel = false;
 
 		[Desc("List of sounds that can be played on impact.")]
-		public readonly string[] ImpactSounds = new string[0];
+		public readonly string[] ImpactSounds = Array.Empty<string>();
 
 		[Desc("Chance of impact sound to play.")]
 		public readonly int ImpactSoundChance = 100;

OpenRA.Mods.Common/Widgets/Logic/Ingame/CommandBarLogic.cs

@@ -26,7 +26,7 @@ namespace OpenRA.Mods.Common.Widgets
 		readonly World world;
 
 		int selectionHash;
-		Actor[] selectedActors = { };
+		Actor[] selectedActors = Array.Empty<Actor>();
 		bool attackMoveDisabled = true;
 		bool forceMoveDisabled = true;
 		bool forceAttackDisabled = true;

OpenRA.Mods.Common/Widgets/Logic/Installation/ModContentLogic.cs

@@ -55,7 +55,7 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 			template = scrollPanel.Get<ContainerWidget>("PACKAGE_TEMPLATE");
 
 			var headerTemplate = panel.Get<LabelWidget>("HEADER_TEMPLATE");
-			var headerLines = !string.IsNullOrEmpty(content.HeaderMessage) ? content.HeaderMessage.Replace("\\n", "\n").Split('\n') : new string[0];
+			var headerLines = !string.IsNullOrEmpty(content.HeaderMessage) ? content.HeaderMessage.Replace("\\n", "\n").Split('\n') : Array.Empty<string>();
 			var headerHeight = 0;
 			foreach (var l in headerLines)
 			{

OpenRA.Mods.Common/Widgets/Logic/Installation/ModContentPromptLogic.cs

@@ -31,7 +31,7 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 
 			var panel = widget.Get("CONTENT_PROMPT_PANEL");
 			var headerTemplate = panel.Get<LabelWidget>("HEADER_TEMPLATE");
-			var headerLines = !string.IsNullOrEmpty(content.InstallPromptMessage) ? content.InstallPromptMessage.Replace("\\n", "\n").Split('\n') : new string[0];
+			var headerLines = !string.IsNullOrEmpty(content.InstallPromptMessage) ? content.InstallPromptMessage.Replace("\\n", "\n").Split('\n') : Array.Empty<string>();
 			var headerHeight = 0;
 			foreach (var l in headerLines)
 			{

OpenRA.Mods.Common/Widgets/ProductionPaletteWidget.cs

@@ -136,7 +136,7 @@ namespace OpenRA.Mods.Common.Widgets
 				count = FieldLoader.GetValue<int>("HotkeyCount", countNode.Value.Value);
 
 			if (count == 0)
-				return new string[0];
+				return Array.Empty<string>();
 
 			if (string.IsNullOrEmpty(prefix))
 				emitError($"{widgetNode.Location} must define HotkeyPrefix if HotkeyCount > 0.");

OpenRA.Mods.Common/Widgets/SupportPowersWidget.cs

@@ -80,7 +80,7 @@ namespace OpenRA.Mods.Common.Widgets
 				count = FieldLoader.GetValue<int>("HotkeyCount", countNode.Value.Value);
 
 			if (count == 0)
-				return new string[0];
+				return Array.Empty<string>();
 
 			if (string.IsNullOrEmpty(prefix))
 				emitError($"{widgetNode.Location} must define HotkeyPrefix if HotkeyCount > 0.");

OpenRA.Mods.D2k/Traits/Buildings/D2kActorPreviewPlaceBuildingPreview.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using OpenRA.Graphics;
@@ -27,7 +28,7 @@ namespace OpenRA.Mods.D2k.Traits
 		public readonly HashSet<string> UnsafeTerrainTypes = new HashSet<string> { "Rock" };
 
 		[Desc("Only check for 'unsafe' footprint tiles when you have these prerequisites.")]
-		public readonly string[] RequiresPrerequisites = { };
+		public readonly string[] RequiresPrerequisites = Array.Empty<string>();
 
 		[Desc("Sprite image to use for the overlay.")]
 		public readonly string Image = "overlay";

OpenRA.Mods.D2k/Traits/Buildings/D2kBuilding.cs

@@ -9,6 +9,7 @@
  */
 #endregion
 
+using System;
 using System.IO;
 using System.Linq;
 using OpenRA.Mods.Common.Terrain;
@@ -43,7 +44,7 @@ namespace OpenRA.Mods.D2k.Traits.Buildings
 		public readonly ushort ConcreteTemplate = 88;
 
 		[Desc("List of required prerequisites to place a terrain template.")]
-		public readonly string[] ConcretePrerequisites = { };
+		public readonly string[] ConcretePrerequisites = Array.Empty<string>();
 
 		public override object Create(ActorInitializer init) { return new D2kBuilding(init, this); }
 	}

OpenRA.Server/Program.cs

@@ -54,7 +54,7 @@ namespace OpenRA.Server
 			// Special case handling of Game.Mod argument: if it matches a real filesystem path
 			// then we use this to override the mod search path, and replace it with the mod id
 			var modID = arguments.GetValue("Game.Mod", null);
-			var explicitModPaths = new string[0];
+			var explicitModPaths = Array.Empty<string>();
 			if (modID != null && (File.Exists(modID) || Directory.Exists(modID)))
 			{
 				explicitModPaths = new[] { modID };

OpenRA.Utility/Program.cs

@@ -73,7 +73,7 @@ namespace OpenRA
 			}
 
 			var modId = args[0];
-			var explicitModPaths = new string[0];
+			var explicitModPaths = Array.Empty<string>();
 			if (File.Exists(modId) || Directory.Exists(modId))
 			{
 				explicitModPaths = new[] { modId };