Merge pull request #58 from zendesk/craig/intersection-complexity

Lower complexity of `Schedule#&` method

lib/biz/schedule.rb

@@ -48,17 +48,8 @@ def in_zone
 
     def &(other)
       self.class.new do |config|
-        config.hours = Interval.to_hours(
-          intervals.flat_map { |interval|
-            other
-              .intervals
-              .map { |other_interval| interval & other_interval }
-              .reject(&:empty?)
-          }
-        )
-
-        config.holidays = [*holidays, *other.holidays].map(&:to_date)
-
+        config.hours     = Interval.to_hours(intersected_intervals(other))
+        config.holidays  = [*holidays, *other.holidays].map(&:to_date)
         config.time_zone = time_zone.name
       end
     end
@@ -67,5 +58,16 @@ def &(other)
 
     attr_reader :configuration
 
+    private
+
+    def intersected_intervals(other)
+      intervals.flat_map { |interval|
+        other
+          .intervals
+          .map { |other_interval| interval & other_interval }
+          .reject(&:empty?)
+      }
+    end
+
   end
 end