let for minitest

gistfile1.rb

require 'minitest/spec'
require 'minitest/autorun'


module Helpers
  module Let
    def let(name, &blk)      
      define_method name do
        @let_assigments ||= {}
        @let_assigments[name] ||= send(:"original_#{name}")
      end
      define_method "original_#{name}", &blk
    end
  end
end


class MiniTest::Unit::TestCase
  extend Helpers::Let
end


describe Helpers::Let do
  let(:hash) { { foo: 'bar' } }

  it "should set hash with foo" do
    hash[:foo].must_equal 'bar'
  end

  it "should return eq objects" do
    hash.object_id.must_equal hash.object_id
  end

  describe "overriding" do
    let(:hash) { super().merge(zoo: 'foo' )}

    it "should override super-let" do
      hash[:foo].must_equal 'bar'
      hash[:zoo].must_equal 'foo'
    end
  end
end