Vital Ruby my_each

x.rb

class Array
  def my_each
    length.times do |index|
      yield(self[index])
    end
  end

  def my_inject(initial_value)
    accumulator = initial_value || self.dup.shift
    my_each do |item|
      accumulator = yield(accumulator, item)
    end
  end
end

describe "My Array Methods" do
  let(:array) { [1,2,3,4] }

  describe "#my_each" do

    it "iterates over each item" do
      sum = 0
      array.my_each do |item| sum += item end
      sum.should == 10
    end
  end

  describe "#my_inject" do
    context "with an explicit initial" do
      it "injects an operation in the array" do
        result = array.my_inject(0) { |acc, item| acc + item }
        result.should == 10
      end
    end

    context "with an implicit initial" do
      it "injects an operation in the array" do
        result = array.my_inject { |acc, item| acc + item }
        result.should == 10
      end
    end
  end
end