use variable params for rating

lib/rank_king.rb

@@ -13,7 +13,7 @@ module RankKing
       ratings = combo.map {|item| Rating.first(axis:, item:) || OS.rating }
       Math.sqrt(
         [ratings, ratings.reverse]
-          .map {|game| [game, OS.rate(game).flatten] }
+          .map {|game| [game, OS.rate(*game).flatten] }
           .sum {|pre,post| pre.zip(post).sum { (_1.sigma - _2.sigma)**2 }}
       )
     }.last
@@ -23,7 +23,7 @@ module RankKing
     fail unless [winner, loser].all? { _1.pool == axis.pool }
 
     game = [winner, loser].map { Rating.first(axis:, item: _1) || OS.rating }
-    result = OS.rate(game).flatten
+    result = OS.rate(*game).flatten
 
     DB.transaction do
       Ranking.create(axis:, winner:, loser:)

lib/rank_king/open_skill.rb

@@ -17,8 +17,7 @@ module RankKing
       @beta = @sigma / 2.0
     end
 
-    # TODO take an implicit array
-    def rate(teams)
+    def rate(*teams)
       # allow for passing in single-rating teams
       teams = teams.map { Array(_1) }
 

test/open_skill_test.rb

@@ -18,7 +18,7 @@ class TestRate < Minitest::Test
   end
 
   def test_rate
-    a2, b2, c2, d2 = @os.rate([[@a1], [@b1], [@c1], [@d1]]).flatten
+    a2, b2, c2, d2 = @os.rate([@a1], [@b1], [@c1], [@d1]).flatten
 
     assert_rating a2, OpenSkill::Rating.new(mu: 30.209971908310553, sigma: 4.764898977359521)
     assert_rating b2, OpenSkill::Rating.new(mu: 27.64460833689499, sigma: 4.882789305097372)