Reflect in naming that negative SelfHealing is a thing.

OpenRA.Mods.Common/Traits/ChangesHealth.cs

@@ -14,30 +14,34 @@ using OpenRA.Traits;
 
 namespace OpenRA.Mods.Common.Traits
 {
-	[Desc("Attach this to actors which should be able to regenerate their health points.")]
-	class SelfHealingInfo : ConditionalTraitInfo, Requires<IHealthInfo>
+	[Desc("Attach this to actors which should regenerate or lose health points over time.")]
+	class ChangesHealthInfo : ConditionalTraitInfo, Requires<IHealthInfo>
 	{
-		[Desc("Absolute amount of health points added in each step.")]
+		[Desc("Absolute amount of health points added in each step.",
+			"Use negative values to apply damage.")]
 		public readonly int Step = 5;
 
 		[Desc("Relative percentages of health added in each step.",
+			"Use negative values to apply damage.",
 			"When both values are defined, their summary will be applied.")]
 		public readonly int PercentageStep = 0;
 
+		[Desc("Time in ticks to wait between each health modification.")]
 		public readonly int Delay = 5;
 
 		[Desc("Heal if current health is below this percentage of full health.")]
-		public readonly int HealIfBelow = 50;
+		public readonly int StartIfBelow = 50;
 
+		[Desc("Time in ticks to wait after taking damage.")]
 		public readonly int DamageCooldown = 0;
 
-		[Desc("Apply the selfhealing using these damagetypes.")]
+		[Desc("Apply the health change when encountering these damage types.")]
 		public readonly BitSet<DamageType> DamageTypes = default(BitSet<DamageType>);
 
-		public override object Create(ActorInitializer init) { return new SelfHealing(init.Self, this); }
+		public override object Create(ActorInitializer init) { return new ChangesHealth(init.Self, this); }
 	}
 
-	class SelfHealing : ConditionalTrait<SelfHealingInfo>, ITick, INotifyDamage
+	class ChangesHealth : ConditionalTrait<ChangesHealthInfo>, ITick, INotifyDamage
 	{
 		readonly IHealth health;
 
@@ -47,7 +51,7 @@ namespace OpenRA.Mods.Common.Traits
 		[Sync]
 		int damageTicks;
 
-		public SelfHealing(Actor self, SelfHealingInfo info)
+		public ChangesHealth(Actor self, ChangesHealthInfo info)
 			: base(info)
 		{
 			health = self.Trait<IHealth>();
@@ -59,7 +63,7 @@ namespace OpenRA.Mods.Common.Traits
 				return;
 
 			// Cast to long to avoid overflow when multiplying by the health
-			if (health.HP >= Info.HealIfBelow * (long)health.MaxHP / 100)
+			if (health.HP >= Info.StartIfBelow * (long)health.MaxHP / 100)
 				return;
 
 			if (damageTicks > 0)
@@ -73,7 +77,7 @@ namespace OpenRA.Mods.Common.Traits
 				ticks = Info.Delay;
 
 				// Cast to long to avoid overflow when multiplying by the health
-				self.InflictDamage(self, new Damage((int)(-(Info.Step + Info.PercentageStep * (long)health.MaxHP / 100)), Info.DamageTypes));
+				self.InflictDamage(self, new Damage((int)-(Info.Step + Info.PercentageStep * (long)health.MaxHP / 100), Info.DamageTypes));
 			}
 		}
 

OpenRA.Mods.Common/UpdateRules/Rules/RenameSelfHealing.cs

@@ -0,0 +1,42 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2020 The OpenRA Developers (see AUTHORS)
+ * This file is part of OpenRA, which is free software. It is made
+ * available to you under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version. For more
+ * information, see COPYING.
+ */
+#endregion
+
+using System.Collections.Generic;
+using System.Linq;
+
+namespace OpenRA.Mods.Common.UpdateRules.Rules
+{
+	public class RenameSelfHealing : UpdateRule
+	{
+		public override string Name { get { return "SelfHealing was renamed as negative SelfHealing is a common usecase."; } }
+		public override string Description
+		{
+			get
+			{
+				return "SelfHealing was renamed to ChangesHealth\n" +
+						"HealIfBelow was renamed to StartIfBelow.";
+			}
+		}
+
+		public override IEnumerable<string> UpdateActorNode(ModData modData, MiniYamlNode actorNode)
+		{
+			var modId = modData.Manifest.Id;
+
+			foreach (var sh in actorNode.ChildrenMatching("SelfHealing"))
+			{
+				sh.RenameChildrenMatching("HealIfBelow", "StartIfBelow");
+				sh.RenameKey("ChangesHealth");
+			}
+
+			yield break;
+		}
+	}
+}

OpenRA.Mods.Common/UpdateRules/UpdatePath.cs

@@ -70,6 +70,7 @@ namespace OpenRA.Mods.Common.UpdateRules
 				new CreateFlashPaletteEffectWarhead(),
 				new ChangeTargetLineDelayToMilliseconds(),
 				new ReplaceFacingAngles(),
+				new RenameSelfHealing(),
 			})
 		};