Provides a single method deprecate to be used to declare when something is going away.

class Legacy
  def self.klass_method
    # ...
  end

  def instance_method
    # ...
  end

  extend Gem::Deprecate
  deprecate :instance_method, "X.z", 2011, 4

  class << self
    extend Gem::Deprecate
    deprecate :klass_method, :none, 2011, 4
  end
end
Methods
D
S
Class Public methods
deprecate(name, repl, year, month)

Simple deprecation method that deprecates name by wrapping it up in a dummy method. It warns on each call to the dummy method telling the user of repl (unless repl is :none) and the year/month that it is planned to go away.

Source: show | on GitHub 

# File lib/rubygems/deprecate.rb, line 49
def deprecate name, repl, year, month
  class_eval {
    old = "_deprecated_#{name}"
    alias_method old, name
    define_method name do |*args, &block| # TODO: really works on 1.8.7?
      klass = self.kind_of? Module
      target = klass ? "#{self}." : "#{self.class}#"
      msg = [ "NOTE: #{target}#{name} is deprecated",
        repl == :none ? " with no replacement" : "; use #{repl} instead",
        ". It will be removed on or after %4d-%02d-01." % [year, month],
        "\n#{target}#{name} called from #{Gem.location_of_caller.join(":")}",
      ]
      warn "#{msg.join}." unless Gem::Deprecate.skip
      send old, *args, &block
    end
  }
end
skip_during()

Temporarily turn off warnings. Intended for tests only.

Source: show | on GitHub 

# File lib/rubygems/deprecate.rb, line 36
def skip_during
  Gem::Deprecate.skip, original = true, Gem::Deprecate.skip
  yield
ensure
  Gem::Deprecate.skip = original
end