a more succinct implementation of Object#try

object_try.rb

# Makes it easy to try more than one method on Object and just return nil if
# the Object doesn't respond to any of the methods. So, rather than:
#
#  obj.try(:foo).try(:bar)
#
# you can just
#
#  obj.try(:foo, :bar)
#
# Based on Object#try from ActiveSupport.
class Object
  def try *methods
    methods.inject(self) do |target, method|
      break unless target.public_methods.include? method.to_s
      target.send method
    end
  end
end

describe "Object#try" do
  before :each do
    @test = Class.new do
      def public_method
        'value 1'
      end

      private
      def private_method
        'value 2'
      end
    end.new
  end

  it "should return the result if all methods exist" do
    @test.try(:public_method, :size).should == 7
  end

  it "should return nil if any of the methods don't exist" do
    @test.try(:public_method, :doesnt_exist).should be_nil
  end

  it "should return nil if any of the methods aren't public" do
    @test.try(:private_method, :length).should be_nil
  end
end