small fixes

app/models/topic_relationship.rb

@@ -3,4 +3,5 @@ class TopicRelationship < ActiveRecord::Base
   belongs_to :child, class_name: 'Topic'
 
   validates_presence_of :parent, :child
+  validates_uniqueness_of :child, scope: :parent
 end

app/services/score_calculator_service.rb

@@ -17,7 +17,9 @@ class ScoreCalculatorService
     sum = 0
 
     Score.all.find_each do |score|
-      sum += (values[score.code.to_sym].to_f / score.max_value.to_f) * score.weight.to_f unless score.max_value.to_f == 0
+      next if score.max_value.to_f == 0
+
+      sum += (values[score.code.to_sym].to_f / score.max_value.to_f) * score.weight.to_f
     end
 
     sum.to_f / sum_weights.to_f
@@ -41,7 +43,7 @@ class ScoreCalculatorService
   end
 
   def sum_weights
-    Score.pluck(:weight).inject(0){|sum,r| sum + r }.to_f
+    Score.pluck(:weight).inject(0.0) { |a, e| a + e }
   end
 
 end

db/seeds/scores.rb

@@ -24,7 +24,7 @@ reputations = [
 ]
 
 values = [
-  [0,0,0,0,0,0,0,0,0], # Iniciante
+  [   0,     0,    0,    0,    0,    0,    0,    0,    0], # Iniciante
   [   25,  3.0,   10,  500,  250,   70,   50,    5,  400],  # Novato
   [   50,  3.8,   20,  550,  350,   85,  250,   15,  600],  # Amador
   [  100,  4.2,   40,  600,  450,   90, 1000,   25,  750],  # Profissional