1# frozen_string_literal: true
2##
3# Provides a single method +deprecate+ to be used to declare when
4# something is going away.
5#
6#     class Legacy
7#       def self.klass_method
8#         # ...
9#       end
10#
11#       def instance_method
12#         # ...
13#       end
14#
15#       extend Gem::Deprecate
16#       deprecate :instance_method, "X.z", 2011, 4
17#
18#       class << self
19#         extend Gem::Deprecate
20#         deprecate :klass_method, :none, 2011, 4
21#       end
22#     end
23
24module Gem::Deprecate
25
26  def self.skip # :nodoc:
27    @skip ||= false
28  end
29
30  def self.skip=(v) # :nodoc:
31    @skip = v
32  end
33
34  ##
35  # Temporarily turn off warnings. Intended for tests only.
36
37  def skip_during
38    Gem::Deprecate.skip, original = true, Gem::Deprecate.skip
39    yield
40  ensure
41    Gem::Deprecate.skip = original
42  end
43
44  ##
45  # Simple deprecation method that deprecates +name+ by wrapping it up
46  # in a dummy method. It warns on each call to the dummy method
47  # telling the user of +repl+ (unless +repl+ is :none) and the
48  # year/month that it is planned to go away.
49
50  def deprecate(name, repl, year, month)
51    class_eval {
52      old = "_deprecated_#{name}"
53      alias_method old, name
54      define_method name do |*args, &block|
55        klass = self.kind_of? Module
56        target = klass ? "#{self}." : "#{self.class}#"
57        msg = [ "NOTE: #{target}#{name} is deprecated",
58          repl == :none ? " with no replacement" : "; use #{repl} instead",
59          ". It will be removed on or after %4d-%02d-01." % [year, month],
60          "\n#{target}#{name} called from #{Gem.location_of_caller.join(":")}",
61        ]
62        warn "#{msg.join}." unless Gem::Deprecate.skip
63        send old, *args, &block
64      end
65    }
66  end
67
68  module_function :deprecate, :skip_during
69
70end
71