Cute little minimum viable Ruby test runner

thing_test.rb

class Thing
  def wobble
    'wobble wobble honk'
  end
end

class ThingTest
  def self.test(name, &block)
    define_method(:"test #{name}", &block)
  end

  def initialize
    @subject = Thing.new
  end

  test 'should wobble' do
    subject.wobble.include?('wobble')
  end

  test 'should not honk' do
    !subject.wobble.include?('honk')
  end

  def run
    test_methods.each do |method_name|
      result = public_send(method_name)
      puts "#{result ? '✅' : '❌'} #{method_name}"
    end
  end

  private

  attr_reader :subject

  def test_methods
    self.class.instance_methods.select do |method_name|
      method_name.start_with?('test')
    end
  end
end

ThingTest.new.run