rauchy

class MyLibrary
  class Configuration
    attr_accessor :protocol, :hostname, :port
  end

  attr_accessor :configuration

  def configure(&block)
    self.configuration ||= Configuration.new
    self.configuration.instance_eval(&block)

rauchy

l = lambda { |first_name, last_name| puts "Hello, #{first_name} #{last_name}!" }

l.call("Omer", "Rauchwerger") # => Hello, Omer Rauchwerger!
l.call("Omer") # => ArgumentError: wrong number of arguments (1 for 2)
l.call("Omer", "Lachish", "Rauchwerger") # => ArgumentError: wrong number of arguments (3 for 2)

rauchy

def connect(address, &log)
  log.call("About to connect…")
  response = do_actual_connection(address)
  log.call("Error: #{response.message}") if response.error?
end

connect("http://localhost") { |msg| puts "Info: #{msg}" }

rauchy

a = 1

Foo = Class.new do
  # a == 1 here
  b = 2

  define_method(:bar) do
    # a == 1 here, b == 2 here
    c = 3
  end

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def greet
  "Hello, #{yield}!"
end

name = "Omer"
greet { name } # => "Hello, Omer!"

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def log
  if block_given?
    puts "before block"
    yield
    puts "after block"
  end
end

log # nothing will be displayed!

rauchy

describe User do
  describe '#visit' do
    it 'increases the visited attractions count after one visit' do
      subject.visit('Rome')
      subject.visited_attractions_count.should == 1
    end 

    it "doesn't increase the visited attractions count after several visits" do
      5.times { subject.visit('Rome') }
      subject.visited_attractions_count.should_not > 1

rauchy

factory :some_model do
  factory :some_other_model do
  end
end