#
# magical binding
#

module RiotA
  module AssertionMacros
    # def equals(expected) puts "yay"; end
    def equals(expected) true; end
  end

  class Assertion
    include AssertionMacros
    attr_reader :name, :actual
    def initialize(name, actual)
      @name, @actual = name, actual
    end
  end

  class Context
    def initialize(name, &context_block) @context_block = context_block; end
    def run; @context_block.call; end
  end

  module ContextMacros
    def asserts(name, &test_block) Assertion.new(name, test_block.call); end
  end

  def self.context(name, &block)
    asserts_m = Object.instance_method(:asserts)
    ctx = Context.new(name, &block)
    asserts_m.bind(ctx)
    ctx.run
  end
end

class Object
  include RiotA::ContextMacros
end

#
# instance eval
#

module RiotB
  class Situation
  end

  module AssertionMacros
    # def equals(expected) puts "aya"; end
    def equals(expected) true; end
  end

  class Assertion
    include AssertionMacros
    attr_reader :name, :actual
    def initialize(name, sitution, &actual_block)
      @name, @actual = name, instance_eval(&actual_block)
    end
  end

  class Context
    def initialize(name, &context_block)
      @situation = Situation.new
      instance_eval(&context_block)
    end
    def asserts(name, &test_block) Assertion.new(name, @situation, &test_block); end
  end

  def self.context(name, &block)
    ctx = Context.new(name, &block)
  end
end

#
# Bench
#

n = 100_000

require 'benchmark'
Benchmark.bmbm do |x|
  x.report("Magical binding") do
    n.times do
      RiotA.context "foo" do
        asserts("something") { "foo" }.equals("bar")
      end
    end
  end

  x.report("Instance eval (current)") do
    n.times do
      RiotB.context "foo" do
        asserts("something") { "foo" }.equals("bar")
      end
    end
  end
end