A ruby script to convert Json file to CSV

convert_json_to_csv.rb

#Ruby version 2.1.1

require 'csv'
require 'json'

def json_to_csv(json_file, csv_file)
  json_array = JSON.parse(File.open(json_file).read)
  headers = collect_keys(json_array.first) 
  CSV.open(csv_file, "w", :write_headers=> true, :headers => headers) do |csv|
    json_array.each { |item| csv << collect_values(item) }
  end
end

def collect_keys(hash, prefix = nil)
  arr = hash.map do |key, value|
    if value.class != Hash
      if prefix
        "#{prefix}.#{key}"
      else
        key
      end
    else
      if prefix
        collect_keys(value, "#{prefix}.#{key}")
      else
        collect_keys(value, "#{key}")
      end
    end
  end
  arr.flatten
end

def collect_values(hash)
  arr = hash.map do |key, value|
    if value.class != Hash
      if (value.class == Array)
        value.join(',')
      else
        value
      end
    else
      collect_values(value)
    end
  end
  arr.flatten
end