deprecate_assertions.rb

module DeprecateAssertions

  def self.methods_to_replace
    [
      :assert,
      :assert_block,
      :assert_equal,
      :assert_no_match,
      :assert_not_equal,
      :assert_nothing_raised,
      :assert_nothing_thrown,
      :assert_not_nil,
      :assert_not_same,
      :assert_raise,
      :assert_respond_to,
      :assert_difference,
      :assert_in_delta,
      :assert_nil,
    ]
  end

  def self.included a
    a.class_eval do
      DeprecateAssertions.methods_to_replace.each do |m|
        alias :"old_#{m}" :"#{m}"
        alias :"#{m}" :"new_#{m}"
      end
    end
  end
  
  DeprecateAssertions.methods_to_replace.each do |m|
    define_method(:"new_#{m}") do |*args|
      warn "[DEPRECATED] '#{m}' is deprecated. Please use RSpec methods instead."
      warn "from: #{caller[0]}"
      send(:"old_#{m}", *args)
    end
  end
  
end

spec_helper.rb

RSpec.configure do |config|
  config.include DeprecateAssertions
  # ...
end