experiment.rb in verdict-0.13.0

- old
+ new

@@ -50,10 +50,21 @@
     @segmenter.instance_eval(&block)
     @segmenter.verify!
     return self
   end
 
+  # Optional: Together with the "end timestamp", limits the experiment run timeline within
+  # the given time interval. When experiment is not scheduled, subject switch returns nil.
+  # This is useful when the experimenter requires the experiment to run in a strict timeline.
+  def schedule_start_timestamp(timestamp)
+    @schedule_start_timestamp = timestamp
+  end
+
+  def schedule_end_timestamp(timestamp)
+    @schedule_end_timestamp = timestamp
+  end
+
   def rollout_percentage(percentage, rollout_group_name = :enabled)
     groups(Verdict::Segmenters::RolloutSegmenter) do
       group rollout_group_name, percentage
     end
   end
@@ -170,10 +181,11 @@
   def remove_subject_assignment(subject)
     @storage.remove_assignment(self, subject)
   end
 
   def switch(subject, context = nil)
+    return unless is_scheduled?
     assign(subject, context).to_sym
   end
 
   def lookup(subject)
     @storage.retrieve_assignment(self, subject)
@@ -237,17 +249,31 @@
   end
 
   def set_start_timestamp
     @storage.store_start_timestamp(self, started_now = Time.now.utc)
     started_now
+  rescue NotImplementedError
+    nil
   end
 
   def ensure_experiment_has_started
-    @started_at ||= @storage.retrieve_start_timestamp(self) || set_start_timestamp
+    @started_at ||= started_at || set_start_timestamp
   rescue Verdict::StorageError
     @started_at ||= Time.now.utc
   end
 
   def nil_assignment(subject)
     subject_assignment(subject, nil, nil)
+  end
+
+  private
+
+  def is_scheduled?
+    if @schedule_start_timestamp and @schedule_start_timestamp > Time.now
+      return false
+    end
+    if @schedule_end_timestamp and @schedule_end_timestamp < Time.now
+      return false
+    end
+    return true
   end
 end