* Added: reset an experiment by calling reset!.

CHANGELOG

@@ -1,6 +1,7 @@
 0.2.2
 * Added: vanity binary, with single command for generating a report.
 * Added: return alternative by value from experiment.alternative(val) method.
+* Added: reset an experiment by calling reset!.
 
 0.2.1 (2009-11-11)
 * Added: z-score and confidence level for A/B test alternatives.

lib/vanity/experiment/ab_test.rb

@@ -262,6 +262,12 @@ def save #:nodoc:
         super
       end
 
+      def reset! #:nodoc:
+        redis.del key(:outcome)
+        alternatives.each(&:destroy)
+        super
+      end
+
       def destroy #:nodoc:
         redis.del key(:outcome)
         alternatives.each(&:destroy)

lib/vanity/experiment/base.rb

@@ -117,7 +117,8 @@ def complete!
 
       # Time stamp when experiment was completed.
       def completed_at
-        Time.at(redis[key(:completed_at)].to_i)
+        time = redis[key(:completed_at)]
+        time && Time.at(time.to_i)
       end
 
       # Returns true if experiment active, false if completed.
@@ -145,6 +146,13 @@ def redis #:nodoc:
       def save #:nodoc:
       end
 
+      # Reset experiment.
+      def reset!
+        @created_at = Time.now
+        redis[key(:created_at)] = @created_at.to_i
+        redis.del key(:completed_at)
+      end
+
       # Get rid of all experiment data.
       def destroy
         redis.del key(:created_at)

test/ab_test_test.rb

@@ -52,11 +52,19 @@ def test_requires_at_least_two_alternatives_per_experiment
       alternatives "foo", "bar"
     end
   end
+
+  def test_returning_alternative_by_value
+    experiment :abcd do
+      alternatives :a, :b, :c, :d
+    end
+    assert_equal experiment(:abcd).alternatives[1], experiment(:abcd).alternative(:b)
+    assert_equal experiment(:abcd).alternatives[3], experiment(:abcd).alternative(:d)
+  end
 
 
   # -- Running experiment --
 
-  def returns_the_same_alternative_consistently
+  def test_returns_the_same_alternative_consistently
     experiment :foobar do
       alternatives "foo", "bar"
       identify { "6e98ec" }
@@ -68,7 +76,7 @@ def returns_the_same_alternative_consistently
     end
   end
 
-  def returns_different_alternatives_for_each_participant
+  def test_returns_different_alternatives_for_each_participant
     experiment :foobar do
       alternatives "foo", "bar"
       identify { rand(1000).to_s }
@@ -78,7 +86,7 @@ def returns_different_alternatives_for_each_participant
     assert_in_delta alts.select { |a| a == "foo" }.count, 500, 100 # this may fail, such is propability
   end
 
-  def records_all_participants_in_each_alternative
+  def test_records_all_participants_in_each_alternative
     ids = (Array.new(200) { |i| i.to_s } * 5).shuffle
     experiment :foobar do
       alternatives "foo", "bar"
@@ -90,7 +98,7 @@ def records_all_participants_in_each_alternative
     assert_in_delta alts.first.participants, 100, 20
   end
 
-  def records_each_converted_participant_only_once
+  def test_records_each_converted_participant_only_once
     ids = (Array.new(100) { |i| i.to_s } * 5).shuffle
     test = self
     experiment :foobar do
@@ -123,6 +131,26 @@ def test_records_conversion_only_for_participants
     assert_equal 100, alts.inject(0) { |t,a| t + a.converted }
   end
 
+  def test_reset_experiment
+    experiment :simple do
+      identify { "me" }
+      complete_if { alternatives.map(&:converted).sum >= 1 }
+      outcome_is { alternative(true) }
+    end
+    experiment(:simple).choose
+    experiment(:simple).conversion!
+    refute experiment(:simple).active?
+    assert_equal true, experiment(:simple).outcome.value
+
+    experiment(:simple).reset!
+    assert experiment(:simple).active?
+    assert_nil experiment(:simple).outcome
+    assert_nil experiment(:simple).completed_at
+    assert_equal 0, experiment(:simple).alternatives.map(&:participants).sum
+    assert_equal 0, experiment(:simple).alternatives.map(&:conversions).sum
+    assert_equal 0, experiment(:simple).alternatives.map(&:converted).sum
+  end
+
 
   # -- A/B helper methods --