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path: root/spec/ruby/core/enumerator/next_spec.rb
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require_relative '../../spec_helper'

describe "Enumerator#next" do
  before :each do
    @enum = 1.upto(3)
  end

  it "returns the next element of the enumeration" do
    @enum.next.should == 1
    @enum.next.should == 2
    @enum.next.should == 3
  end

  it "raises a StopIteration exception at the end of the stream" do
    3.times { @enum.next }
    lambda { @enum.next }.should raise_error(StopIteration)
  end

  it "cannot be called again until the enumerator is rewound" do
    3.times { @enum.next }
    lambda { @enum.next }.should raise_error(StopIteration)
    lambda { @enum.next }.should raise_error(StopIteration)
    lambda { @enum.next }.should raise_error(StopIteration)
    @enum.rewind
    @enum.next.should == 1
  end
end