lib/dat/science/experiment.rb in dat-science-1.1.0 vs lib/dat/science/experiment.rb in dat-science-1.2.0

@@ -11,10 +11,12 @@
 
       # Public: Create a new experiment instance. `self` is yielded to an
       # optional `block` if it's provided.
       def initialize(name, &block)
         @candidate  = nil
+        @cleaner    = lambda { |r| r }
+        @comparator = lambda { |a, b| a == b }
         @context    = { :experiment => name }
         @control    = nil
         @name       = name
 
         yield self if block_given?
@@ -25,10 +27,42 @@
       def candidate(&block)
         @candidate = block if block
         @candidate
       end
 
+      # Internal: Run the cleaner on a value.
+      def clean(value)
+        cleaner.call value
+      end
+
+      # Public: Declare a cleaner `block` to scrub the result before it's
+      # published. `block` is called twice, once with the result of
+      # the control behavior and once with the result of the candidate.
+      # Exceptions during cleaning are treated as if they were raised
+      # in a candidate or control behavior block: They're reported as part
+      # of the result.
+      #
+      # Returns `block`.
+      def cleaner(&block)
+        @cleaner = block if block
+        @cleaner
+      end
+
+      # Internal: Run the comparator on two values.
+      def compare(a, b)
+        comparator.call a, b
+      end
+
+      # Public: Declare a comparator `block`. Results are compared with
+      # `==` by default.
+      #
+      # Returns `block`.
+      def comparator(&block)
+        @comparator = block if block
+        @comparator
+      end
+
       # Public: Add a Hash of `payload` data to be included when events are
       # published or returns the current context if `payload` is `nil`.
       def context(payload = nil)
         @context.merge! payload if payload
         @context
@@ -105,10 +139,10 @@
         rescue => ex
           raised = ex
         end
 
         duration = (Time.now - start) * 1000
-        Science::Result.new value, duration, raised
+        Science::Result.new self, value, duration, raised
       end
 
 
       # Internal. Returns a Dat::Science::Result for `candidate`.
       def observe_candidate