lib/roulette-wheel-selection.rb in roulette-wheel-selection-1.0.0 vs lib/roulette-wheel-selection.rb in roulette-wheel-selection-1.0.1

@@ -17,10 +17,11 @@
       hash = array.map{|v| [v, v[key]] }.to_h
       return sample_from_hash(hash)
     end
 
     def sample_from_hash(hash)
-      total_rate = hash.values.inject(&:+)
+      total_rate = hash.values.inject(&:+) || 0
+      return if total_rate == 0
       random_seed = rand(total_rate)
       hash.each do |obj, rate|
         return obj if random_seed < rate
         random_seed -= rate
       end