BUGFIX: UserStat spec was over ambitious with its mocking

app/models/user_stat.rb

@@ -55,15 +55,27 @@ class UserStat < ActiveRecord::Base
   MAX_TIME_READ_DIFF = 100
   # attempt to add total read time to user based on previous time this was called
   def update_time_read!
-    last_seen_key = "user-last-seen:#{id}"
-    last_seen = $redis.get(last_seen_key)
-    if last_seen.present?
+    if last_seen = last_seen_cached
       diff = (Time.now.to_f - last_seen.to_f).round
       if diff > 0 && diff < MAX_TIME_READ_DIFF
         UserStat.where(user_id: id, time_read: time_read).update_all ["time_read = time_read + ?", diff]
       end
     end
-    $redis.set(last_seen_key, Time.now.to_f)
+    cache_last_seen(Time.now.to_f)
+  end
+
+  private
+
+  def last_seen_key
+    @last_seen_key ||= "user-last-seen:#{id}"
+  end
+
+  def last_seen_cached
+    $redis.get(last_seen_key)
+  end
+
+  def cache_last_seen(val)
+    $redis.set(last_seen_key, val)
   end
 
 end

spec/models/user_stat_spec.rb

@@ -77,14 +77,14 @@ describe UserStat do
     let(:stat) { user.user_stat }
 
     it 'makes no changes if nothing is cached' do
-      $redis.expects(:get).with("user-last-seen:#{user.id}").returns(nil)
+      stat.expects(:last_seen_cached).returns(nil)
       stat.update_time_read!
       stat.reload
       stat.time_read.should == 0
     end
 
     it 'makes a change if time read is below threshold' do
-      $redis.expects(:get).with("user-last-seen:#{user.id}").returns(Time.now - 10.0)
+      stat.expects(:last_seen_cached).returns(Time.now - 10)
       stat.update_time_read!
       stat.reload
       stat.time_read.should == 10
@@ -92,7 +92,7 @@ describe UserStat do
 
     it 'makes no change if time read is above threshold' do
       t = Time.now - 1 - UserStat::MAX_TIME_READ_DIFF
-      $redis.expects(:get).with("user-last-seen:#{user.id}").returns(t)
+      stat.expects(:last_seen_cached).returns(t)
       stat.update_time_read!
       stat.reload
       stat.time_read.should == 0