Consolidate rank_member_in logic.

We sometimes need to remove a rank in the ties leaderboard.
Fixes #53.

.ruby-version

@@ -1 +1 @@
-ruby-2.1.2
+ruby-2.2.1

.travis.yml

@@ -1,5 +1,5 @@
 language: ruby
 rvm:
-  - 2.1.2
+  - 2.2.1
 services:
-  - redis-server
+  - redis-server

lib/tie_ranking_leaderboard.rb

@@ -73,9 +73,13 @@ def change_score_for_member_in(leaderboard_name, member, delta)
   # @param score [float] Member score.
   # @param member_data [String] Optional member data.
   def rank_member_in(leaderboard_name, member, score, member_data = nil)
+    member_score = @redis_connection.zscore(leaderboard_name, member) || nil
+    can_delete_score = member_score && members_from_score_range_in(leaderboard_name, member_score, member_score).length == 1
+
     @redis_connection.multi do |transaction|
       transaction.zadd(leaderboard_name, score, member)
       transaction.zadd(ties_leaderboard_key(leaderboard_name), score, score.to_f.to_s)
+      transaction.zrem(ties_leaderboard_key(leaderboard_name), member_score.to_f.to_s) if can_delete_score
       transaction.hset(member_data_key(leaderboard_name), member, member_data) if member_data
     end
   end
@@ -87,12 +91,8 @@ def rank_member_in(leaderboard_name, member, score, member_data = nil)
   # @param score [float] Member score.
   # @param member_data [String] Optional member data.
   def rank_member_across(leaderboards, member, score, member_data = nil)
-    @redis_connection.multi do |transaction|
-      leaderboards.each do |leaderboard_name|
-        transaction.zadd(leaderboard_name, score, member)
-        transaction.zadd(ties_leaderboard_key(leaderboard_name), score, score.to_f.to_s)
-        transaction.hset(member_data_key(leaderboard_name), member, member_data) if member_data
-      end
+    leaderboards.each do |leaderboard_name|
+      rank_member_in(leaderboard_name, member, score, member_data)
     end
   end
 
@@ -105,11 +105,8 @@ def rank_members_in(leaderboard_name, *members_and_scores)
       members_and_scores.flatten!
     end
 
-    @redis_connection.multi do |transaction|
-      members_and_scores.each_slice(2) do |member_and_score|
-        transaction.zadd(leaderboard_name, member_and_score[1], member_and_score[0])
-        transaction.zadd(ties_leaderboard_key(leaderboard_name), member_and_score[0], member_and_score[0].to_f.to_s)
-      end
+    members_and_scores.each_slice(2) do |member_and_score|
+      rank_member_in(leaderboard_name, member_and_score[0], member_and_score[1])
     end
   end
 

spec/reverse_tie_ranking_leaderboard_spec.rb

@@ -171,5 +171,21 @@
 
       leaderboard.disconnect
     end
+
+    it 'should output the correct rank when initial score is 0 and then later scores are tied' do
+      # See https://github.com/agoragames/leaderboard/issues/53
+      leaderboard = TieRankingLeaderboard.new('ties', {:reverse => true}, {:host => "127.0.0.1", :db => 15})
+
+      leaderboard.rank_members('member_1', 0, 'member_2', 0)
+      expect(leaderboard.rank_for('member_1')).to eq(1)
+      expect(leaderboard.rank_for('member_2')).to eq(1)
+      leaderboard.rank_members('member_1', 1, 'member_2', 1)
+      expect(leaderboard.rank_for('member_1')).to eq(1)
+      expect(leaderboard.rank_for('member_2')).to eq(1)
+      leaderboard.rank_members('member_1', 1, 'member_2', 1, 'member_3', 4)
+      expect(leaderboard.rank_for('member_3')).to eq(2)
+      expect(leaderboard.rank_for('member_1')).to eq(1)
+      expect(leaderboard.rank_for('member_2')).to eq(1)
+    end
   end
 end

spec/tie_ranking_leaderboard_spec.rb

@@ -300,5 +300,21 @@
         expect(ttl).to be <= 10
       end
     end
+
+    it 'should output the correct rank when initial score is 0 and then later scores are tied' do
+      # See https://github.com/agoragames/leaderboard/issues/53
+      leaderboard = TieRankingLeaderboard.new('ties', Leaderboard::DEFAULT_OPTIONS, {:host => "127.0.0.1", :db => 15})
+
+      leaderboard.rank_members('member_1', 0, 'member_2', 0)
+      expect(leaderboard.rank_for('member_1')).to eq(1)
+      expect(leaderboard.rank_for('member_2')).to eq(1)
+      leaderboard.rank_members('member_1', 1, 'member_2', 1)
+      expect(leaderboard.rank_for('member_1')).to eq(1)
+      expect(leaderboard.rank_for('member_2')).to eq(1)
+      leaderboard.rank_members('member_1', 1, 'member_2', 1, 'member_3', 4)
+      expect(leaderboard.rank_for('member_3')).to eq(1)
+      expect(leaderboard.rank_for('member_1')).to eq(2)
+      expect(leaderboard.rank_for('member_2')).to eq(2)
+    end
   end
 end