Use idiomatic ruby Array methods (#4338)

lib/sidekiq/api.rb

@@ -140,13 +140,8 @@ module Sidekiq
             end
           }
 
-          i = 0
-          array_of_arrays = queues.each_with_object({}) { |queue, memo|
-            memo[queue] = lengths[i]
-            i += 1
-          }.sort_by { |_, size| size }
-
-          Hash[array_of_arrays.reverse]
+          array_of_arrays = queues.zip(lengths).sort_by { |_, size| -size }
+          Hash[array_of_arrays]
         end
       end
     end
@@ -168,18 +163,12 @@ module Sidekiq
       private
 
       def date_stat_hash(stat)
-        i = 0
         stat_hash = {}
-        keys = []
-        dates = []
+        dates = @start_date.downto(@start_date - @days_previous + 1).map { |date|
+          date.strftime("%Y-%m-%d")
+        }
 
-        while i < @days_previous
-          date = @start_date - i
-          datestr = date.strftime("%Y-%m-%d")
-          keys << "stat:#{stat}:#{datestr}"
-          dates << datestr
-          i += 1
-        end
+        keys = dates.map { |datestr| "stat:#{stat}:#{datestr}" }
 
         begin
           Sidekiq.redis do |conn|
@@ -523,7 +512,7 @@ module Sidekiq
         else
           # multiple jobs with the same score
           # find the one with the right JID and push it
-          hash = results.group_by { |message|
+          matched, nonmatched = results.partition { |message|
             if message.index(jid)
               msg = Sidekiq.load_json(message)
               msg["jid"] == jid
@@ -532,12 +521,12 @@ module Sidekiq
             end
           }
 
-          msg = hash.fetch(true, []).first
+          msg = matched.first
           yield msg if msg
 
           # push the rest back onto the sorted set
           conn.multi do
-            hash.fetch(false, []).each do |message|
+            nonmatched.each do |message|
               conn.zadd(parent.name, score.to_f.to_s, message)
             end
           end
@@ -785,10 +774,9 @@ module Sidekiq
         # the hash named key has an expiry of 60 seconds.
         # if it's not found, that means the process has not reported
         # in to Redis and probably died.
-        to_prune = []
-        heartbeats.each_with_index do |beat, i|
-          to_prune << procs[i] if beat.nil?
-        end
+        to_prune = procs.select.with_index { |proc, i|
+          heartbeats[i].nil?
+        }
         count = conn.srem("processes", to_prune) unless to_prune.empty?
       end
       count