Mutations found on initial run http://youtu.be/xrMsQxy_YO0 / https://github.com/paneq/inventory-mutation

m1.txt

evil:Inventory#change_quantity:/home/rupert/ssd/rupert/develop/paneq/inventory-mutation/lib/inventory.rb:18:a2bf6
@@ -1,8 +1,8 @@
 def change_quantity(identifier, qty)
   if (((qty - @reserved_quantity[identifier].sum) - @sold_quantity[identifier].sum) < 0)
-    raise(StandardError, "quantity too low")
+    raise
   end
   @available_quantity[identifier] << (-@available_quantity[identifier].last)
   @available_quantity[identifier] << qty
 end
-----------------------

m2.txt

evil:Inventory#initialize:/home/rupert/ssd/rupert/develop/paneq/inventory-mutation/lib/inventory.rb:4:1c049
@@ -1,12 +1,12 @@
 def initialize
   @available_quantity = Hash.new do |hash, key|
-    hash[key] = [0]
+    hash[key] = []
   end
   @reserved_quantity = Hash.new do |hash, key|
     hash[key] = [0]
   end
   @sold_quantity = Hash.new do |hash, key|
     hash[key] = [0]
   end
 end
-----------------------

m3.txt

evil:Inventory#refund_product:/home/rupert/ssd/rupert/develop/paneq/inventory-mutation/lib/inventory.rb:48:a9f80
@@ -1,7 +1,7 @@
 def refund_product(identifier, qty)
-  if (qty > sold_quantity(identifier))
+  if (qty >= sold_quantity(identifier))
     raise(StandardError, "quantity too big")
   end
   @sold_quantity[identifier] << (-qty)
 end
-----------------------