describe :kernel_then, shared: true do
  it "yields self" do
    object = Object.new
    object.send(@method) { |o| o.should.equal? object }
  end

  it "returns the block return value" do
    object = Object.new
    object.send(@method) { 42 }.should.equal? 42
  end

  it "returns a sized Enumerator when no block given" do
    object = Object.new
    enum = object.send(@method)
    enum.should.instance_of? Enumerator
    enum.size.should.equal? 1
    enum.peek.should.equal? object
    enum.first.should.equal? object
  end
end