dice fixes + updates

lib/dice.dart

@@ -1 +1 @@
-export 'package:dungeon_world_data/dw_data.dart' show Dice;
+export 'package:dungeon_world_data/dw_data.dart' show Dice, DiceResult;

lib/src/dice.dart

@@ -39,7 +39,22 @@ class Dice {
     }
 
     if (obj is num) {
-      return Dice(sides, amount * obj);
+      return Dice(sides, (amount * obj).toInt());
+    }
+
+    return this;
+  }
+
+  Dice operator /(obj) {
+    if (obj is Dice) {
+      if (obj.sides != sides) {
+        throw ("Can't divide different sided die!");
+      }
+      return Dice(sides, obj.amount / amount);
+    }
+
+    if (obj is num) {
+      return Dice(sides, amount ~/ obj);
     }
 
     return this;
@@ -54,7 +69,7 @@ class Dice {
     }
 
     if (obj is num) {
-      return Dice(sides, amount + obj);
+      return Dice(sides, amount + obj.toInt());
     }
 
     return this;
@@ -69,7 +84,7 @@ class Dice {
     }
 
     if (obj is num) {
-      return Dice(sides, amount - obj);
+      return Dice(sides, amount - obj.toInt());
     }
 
     return this;
@@ -97,6 +112,9 @@ class Dice {
     return DiceResult(this, results);
   }
 
+  Dice get single => this / amount;
+  Dice multiple(int amount) => single * amount;
+
   /// Roll arbitrary amount of (possibly) different sided dice.
   static List<DiceResult> roll(List<Dice> dice) {
     var results = <DiceResult>[];

test/dice_test.dart

@@ -21,8 +21,18 @@ void main() {
     });
 
     test('Equality', () {
-      var dice = Dice(12);
-      expect(dice, equals(Dice.d12));
+      var compare = {
+        Dice(4): Dice.d4,
+        Dice(6): Dice.d6,
+        Dice(8): Dice.d8,
+        Dice(10): Dice.d10,
+        Dice(12): Dice.d12,
+        Dice(20): Dice.d20,
+      };
+      for (var d in compare.keys) {
+        expect(d, equals(compare[d]));
+        expect(compare.values.where((el) => el == d).length, equals(1));
+      }
     });
 
     test('Roll', () {