Find most popular item in the array

popular.rb

#! /usr/bin/ruby

def popular(a)
  b = a.uniq
  c = 0
  b.map {|x| c = x if a.count(x) > c} 
  c
end


def test
  failed = false
  if popular([1, 1, 1, 2, 2, 5, 5, 5, 5, 4, 4]) != 5
    failed = true
    puts "fail test 1"
  end

  if popular([1, 1, 1, 2, 2, 5, 5, 5, 1, 1, 1, 1, 1]) != 1
    failed = true
    puts "fail test 2"
  end

  if popular([9, 9, 1, 1, 2, 2, 2]) != 2
    failed = true
    puts "fail test 3"
  end

  puts "Success" unless failed
end
test