updated Hash extensions and specs

lib/redistat/core_ext/hash.rb

@@ -1,21 +1,23 @@
 class Hash
   
   def merge_and_incr(hash)
-    raise ArgumentError unless hash.is_a?(Hash)
-    hash.each do |key, value|
-      if value.is_a?(Numeric)
-        self.set_or_incr(key, value)
-      else
-        self[key] = value
-      end
-    end
+    self.clone.merge_and_incr!(hash)
   end
   
-  def set_or_incr(key, value)
-    return self unless value.is_a?(Numeric)
-    self[key] = 0 unless self.has_key?(key)
-    self[key] += value if self[key].is_a?(Numeric)
+  def merge_and_incr!(hash)
+    raise ArgumentError unless hash.is_a?(Hash)
+    hash.each do |key, value|
+      self[key] = value unless self.set_or_incr(key, value)
+    end
     self
   end
   
+  def set_or_incr(key, value)
+    return false unless value.is_a?(Numeric)
+    self[key] = 0 unless self.has_key?(key)
+    return false unless self[key].is_a?(Numeric)
+    self[key] += value
+    true
+  end
+  
 end