github.rb

#!/usr/bin/env ruby

require 'rubygems'
require 'json'
require 'net/http'

class GitHub

  def initialize(username)
    @username = username
  end

  def data
    url = "http://github.com/api/v1/json/#{username}"
    resp = Net::HTTP.get_response(URI.parse(url))
    data = resp.body
    result = JSON.parse(data)
    return result
  end

  def username
    @username
  end

  def repositories
    repos = []
    data['user']['repositories'].each { |key, value| repos << key['name'] }
    return repos
  end

  def name
    data['user']['name']
  end

end

if ARGV.size == 1

  GitHub.new(ARGV[0]).repositories.each do |repo|
    puts "[#{repo}]"
    if !File.exist?(repo)
      puts "=> Cloning"
      system "git clone -q git@github.com:#{ARGV[0]}/#{repo}.git"
    else
      puts "=> Pulling & Pushing"
      system "cd #{repo} && git pull && git push"
    end

  end

else

  puts "=> Please provide your GitHub username"

end

github_test.rb

require 'test/unit'
require 'github'

class TestGitHub < Test::Unit::TestCase

  def setup
    @github = GitHub.new('fesplugas')
  end

  def test_should_return_name
    assert_equal "Francesc Esplugas", @github.name
  end

  def test_should_return_repositories_list
    assert @github.repositories.include?('typus')
  end

  def test_error
    @github = GitHub.new('fesplugues')
    assert_raise JSON::ParserError do
      @github.data
    end
  end

end