fake_email_generator.rb

# Fake email id generator for Gmail
# These emails will come to real email id you have provided to this script

require 'csv'

def generate_fake_emails(email, count = 1)
  result = []
  username, domain = email.split('@')
  count.times do |c|
    result << "#{username}+#{c+1}@#{domain}"
  end
  result
end

def create_csv(emails)
  CSV.open('email_ids.csv', 'w') do |csv|
    csv << ["Email"]
    emails.each { |e| csv << [e] }
  end
end

puts "Enter real email id"
email = gets
puts "How many fake emails you want?"
count = gets.to_i

fake_emails = generate_fake_emails(email, count)
create_csv(fake_emails)
puts "email_ids.csv generated with #{count} fake email ids"

fake_email_generator_spec.rb

require_relative './fake_email_generator'

describe "Fake Email Generator" do

   it "creates fake email id's from a real email id" do
     generate_fake_emails("abc@def.com").should == ["abc+1@def.com"]
     generate_fake_emails("abc@def.com", 2).should == ["abc+1@def.com", "abc+2@def.com"]
     generate_fake_emails("test@def.com", 0).should == [])
   end

 end