monkey patch of the enumerable class that adds a "to_hash" method

hashmogrify.rb

module Enumerable
  def hashmogrify(&block)
    hash = {}
    self.each do |e|
      result = block.call(e)
      
      if result.is_a?(Array)
        hash[result[0]] = result[1]
      else
        hash[result] = e
      end
    end

    hash
  end
end

describe "Enumerable#to_hash" do
  it "creates a hash from any enumerable object" do
    [].hashmogrify(&:whatever).should be_a Hash
  end

  it "uses an object attribute to create the keys for the hash" do
    ["foo", "barr", "bazzz"].to_hash(&:length).keys.should == [3,4,5]
  end

  it "can accept a block to define a custom key function" do
    hash = ["foo", "bar", "baz"].hashmogrify { |s| s.reverse }
    hash.keys.should == ["oof", "rab", "zab"]
  end

  it "sets the values in the hash to the enumerated objects" do
    hash = ["foo", "bar", "baz"].hashmogrify { |s| s.reverse }
    hash.values.should == ["foo", "bar", "baz"]
  end

  it "can accept a block to define both the keys and the values in the hash" do
    hash = ["foo", "barr", "bazzz"].hashmogrify { |s| [s, s.length] }
    hash.should == {
      "foo" => 3,
      "barr" => 4,
      "bazzz" => 5
    }
  end
end