add tests for ListController.best_period_for

app/controllers/list_controller.rb

@@ -302,7 +302,7 @@ class ListController < ApplicationController
     topic_query = TopicQuery.new(current_user, options)
 
     if current_user.present?
-      periods = [best_period_for(current_user.previous_visit_at)]
+      periods = [ListController.best_period_for(current_user.previous_visit_at)]
     else
       periods = TopTopic.periods
     end
@@ -312,7 +312,7 @@ class ListController < ApplicationController
     top
   end
 
-  def best_period_for(date)
+  def self.best_period_for(date)
     date ||= 1.year.ago
     return :yearly  if date < 180.days.ago
     return :monthly if date <  35.days.ago

spec/controllers/list_controller_spec.rb

@@ -215,4 +215,31 @@ describe ListController do
     end
   end
 
+  describe "best_period_for" do
+
+    it "returns yearly for more than 180 days" do
+      ListController.best_period_for(nil).should == :yearly
+      ListController.best_period_for(180.days.ago).should == :yearly
+    end
+
+    it "returns monthly when less than 180 days and more than 35 days" do
+      (35...180).each do |date|
+        ListController.best_period_for(date.days.ago).should == :monthly
+      end
+    end
+
+    it "returns weekly when less than 35 days and more than 8 days" do
+      (8...35).each do |date|
+        ListController.best_period_for(date.days.ago).should == :weekly
+      end
+    end
+
+    it "returns daily when less than 8 days" do
+      (0...8).each do |date|
+        ListController.best_period_for(date.days.ago).should == :daily
+      end
+    end
+
+  end
+
 end