Merge branch 'master' into replace-sounds-with-sound-specifier

# Conflicts:
#	Content.Server/Hands/Components/HandsComponent.cs
#	Content.Server/Light/Components/ExpendableLightComponent.cs
#	Content.Shared/Light/Component/SharedExpendableLightComponent.cs

Content.Shared/Chemistry/Metabolizable/DefaultMetabolizable.cs

@@ -1,11 +1,13 @@
-using Content.Shared.Chemistry.Reagent;
+using Content.Shared.Chemistry.Reagent;
 using Robust.Shared.GameObjects;
 using Robust.Shared.Serialization.Manager.Attributes;
 
 namespace Content.Shared.Chemistry.Metabolizable
 {
     /// <summary>
-    ///     Default metabolism for reagents. Metabolizes the reagent with no effects
+    ///     Default metabolization for reagents. Returns the amount of reagents metabolized without applying effects.
+    ///     Metabolizes reagents at a constant rate, limited by how much is available. Other classes are derived from
+    ///     this class, so that they do not need their own metabolization quantity calculation.
     /// </summary>
     [DataDefinition]
     public class DefaultMetabolizable : IMetabolizable
@@ -13,12 +15,22 @@ namespace Content.Shared.Chemistry.Metabolizable
         /// <summary>
         ///     Rate of metabolism in units / second
         /// </summary>
-        [DataField("rate")]
-        public double MetabolismRate { get; set; } = 1;
+        [DataField("rate")] public ReagentUnit MetabolismRate { get; set; } = ReagentUnit.New(1);
 
-        ReagentUnit IMetabolizable.Metabolize(IEntity solutionEntity, string reagentId, float tickTime)
+        public virtual ReagentUnit Metabolize(IEntity solutionEntity, string reagentId, float tickTime, ReagentUnit availableReagent)
         {
-            return ReagentUnit.New(MetabolismRate * tickTime);
+
+            // How much reagent should we metabolize
+            // The default behaviour is to metabolize at a constant rate, independent of the quantity of reagents.
+            var amountMetabolized = MetabolismRate * tickTime;
+
+            // is that much reagent actually available?
+            if (availableReagent < amountMetabolized)
+            {
+                return availableReagent;
+            }
+
+            return amountMetabolized;
         }
     }
 }

Content.Shared/Chemistry/Metabolizable/IMetabolizable.cs

@@ -1,4 +1,4 @@
-using Content.Shared.Chemistry.Reagent;
+using Content.Shared.Chemistry.Reagent;
 using Robust.Shared.GameObjects;
 
 namespace Content.Shared.Chemistry.Metabolizable
@@ -16,7 +16,8 @@ namespace Content.Shared.Chemistry.Metabolizable
         /// <param name="solutionEntity">The entity containing the solution.</param>
         /// <param name="reagentId">The reagent id</param>
         /// <param name="tickTime">The time since the last metabolism tick in seconds.</param>
+        /// <param name="availableReagent">Reagent available to be metabolized.</param>
         /// <returns>The amount of reagent to be removed. The metabolizing organ should handle removing the reagent.</returns>
-        ReagentUnit Metabolize(IEntity solutionEntity, string reagentId, float tickTime);
+        ReagentUnit Metabolize(IEntity solutionEntity, string reagentId, float tickTime, ReagentUnit availableReagent);
     }
 }

Content.Shared/Chemistry/Reagent/ReagentEntityReaction.cs

@@ -12,7 +12,7 @@ namespace Content.Shared.Chemistry.Reagent
         Ingestion,
     }
 
-    [DataDefinition]
+    [ImplicitDataDefinitionForInheritors]
     public abstract class ReagentEntityReaction
     {
         [ViewVariables]