Fixed incorrect logic when computing descriptions of stacked abilities (

#260)

FrEee/Game/Objects/Abilities/Ability.cs

@@ -24,18 +24,29 @@ public Ability(IAbilityObject container)
  Values = new List<Formula<string>>();
  }
 
- public Ability(IAbilityObject container, AbilityRule rule, string? description = null, params object[] values)
+ public Ability(IAbilityObject container, AbilityRule rule, Formula<string>? description = null, params object[] values)
  {
  Container = container;
  Rule = rule;
  Description = description;
  Values = new List<Formula<string>>();
  foreach (var val in values)
  {
- if (val is IFormula)
- Values.Add((val as IFormula).ToStringFormula());
+ if (val is IFormula f)
+ {
+ Values.Add(f.ToStringFormula());
+ }
+ else if (val is IEnumerable<IFormula> fs)
+ {
+ foreach (var ff in fs)
+ {
+ Values.Add(ff.ToStringFormula());
+ }
+ }
  else
+ {
  Values.Add(new LiteralFormula<string>(val.ToString()));
+ }
  }
  }
 
@@ -73,7 +84,7 @@ public Ability(IAbilityObject container, AbilityRule rule, string? description =
  /// A description of the ability's effects.
  /// Can use, e.g. [%Amount1%] to specify the amount in the Value 1 field.
  /// </summary>
- public Formula<string> Description { get; set; }
+ public Formula<string>? Description { get; set; }
 
  /// <summary>
  /// Key for ability groups.

FrEee/Utility/Extensions/GameEnumerableExtensions.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Drawing;
 using System.Linq;
@@ -289,19 +289,34 @@ public static IEnumerable<Ability> StackAbilities(this IEnumerable<IAbilityObjec
  /// <returns></returns>
  public static ILookup<Ability, Ability> StackToTree(this IEnumerable<Ability> abilities, IAbilityObject stackTo)
  {
+ // create result list
  var stacked = new List<Tuple<Ability, Ability>>();
+
+ // group abilities by rule
  var grouped = abilities.GroupBy(a => a.Rule);
+
  foreach (var group in grouped)
  {
  if (group.Key == null)
  continue; // invalid ability rule
+
+ // stack this ability group
  var lookup = group.Key.GroupAndStack(group, stackTo);
+
  foreach (var lgroup in lookup)
  {
+ // create a merged ability with a generated description (since ability values are stacked when merged)
+ var mergedAbility = new Ability(stackTo, lgroup.Key.Rule, description: null, values: lgroup.Key.Values);
+
  foreach (var abil in group)
- stacked.Add(Tuple.Create(lgroup.Key, abil));
+ {
+ // add this ability to the current group in the result list, using the merged ability as the key
+ stacked.Add(Tuple.Create(mergedAbility, abil));
+ }
  }
  }
+
+ // create a lookup from the result list
  return stacked.ToLookup(t => t.Item1, t => t.Item2);
  }
 
@@ -361,4 +376,4 @@ public static Cargo Sum<T>(this IEnumerable<T> stuff, Func<T, Cargo> selector)
  return list.BelongingTo(null);
  }
  }
-}
+}