delegator_minitest.rb

require 'delegate'

class Bar < SimpleDelegator
  def initialize(obj)
    super(obj)
  end
end

class Foo
end

require 'minitest/autorun'

describe Bar do
  subject { Bar.new(Foo.new) }

  it "assert kind of Bar" do
    assert_kind_of(Bar, subject)  # => true
  end

  it "must be kind of Bar" do
    subject.must_be_kind_of Bar  # => false
  end

  it "assert instance of Bar" do
    assert_instance_of(Bar, subject)  # => true
  end

  it "must be instance of Bar" do
    subject.must_be_instance_of Bar  # => false
  end
end