summaryrefslogtreecommitdiff
path: root/lib/chef/mixin/deprecation.rb
blob: 04c40dcf29bac45813483dc90a4f789a0c6ab35d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
#
# Author:: Daniel DeLeo (<dan@chef.io>)
# Copyright:: Copyright 2010-2016, Chef Software Inc.
# License:: Apache License, Version 2.0
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

class Chef
  module Mixin


      def self.deprecated_constants
        @deprecated_constants ||= {}
      end

      # Add a deprecated constant to the Chef::Mixin namespace.
      # === Arguments
      # * name: the constant name, as a relative symbol.
      # * replacement: the constant to return instead.
      # * message: A message telling the user what to do instead.
      # === Example:
      #   deprecate_constant(:RecipeDefinitionDSLCore, Chef::DSL::Recipe, <<-EOM)
      #     Chef::Mixin::RecipeDefinitionDSLCore is deprecated, use Chef::DSL::Recipe instead.
      #   EOM
      def self.deprecate_constant(name, replacement, message)
        deprecated_constants[name] = {:replacement => replacement, :message => message}
      end

      # Const missing hook to look up deprecated constants defined with
      # deprecate_constant. Emits a warning to the logger and returns the
      # replacement constant. Will call super, most likely causing an exception
      # for the missing constant, if +name+ is not found in the
      # deprecated_constants collection.
      def self.const_missing(name)
        if new_const = deprecated_constants[name]
          Chef::Log.warn(new_const[:message])
          Chef::Log.warn("Called from: \n#{caller[0...3].map {|l| "\t#{l}"}.join("\n")}")
          new_const[:replacement]
        else
          super
        end
      end

    module Deprecation

      class DeprecatedObjectProxyBase
        KEEPERS = %w{__id__ __send__ instance_eval == equal? initialize object_id}
        instance_methods.each { |method_name| undef_method(method_name) unless KEEPERS.include?(method_name.to_s)}
      end

      class DeprecatedInstanceVariable < DeprecatedObjectProxyBase
        def initialize(target, ivar_name, level=nil)
          @target, @ivar_name = target, ivar_name
          @level ||= :warn
        end

        def method_missing(method_name, *args, &block)
          log_deprecation_msg(caller[0..3])
          @target.send(method_name, *args, &block)
        end

        def inspect
          @target.inspect
        end

        private

        def log_deprecation_msg(*called_from)
          called_from = called_from.flatten
          log("Accessing #{@ivar_name} by the variable @#{@ivar_name} is deprecated. Support will be removed in a future release.")
          log("Please update your cookbooks to use #{@ivar_name} in place of @#{@ivar_name}. Accessed from:")
          called_from.each {|l| log(l)}
        end

        def log(msg)
          # WTF: I don't get the log prefix (i.e., "[timestamp] LEVEL:") if I
          # send to Chef::Log. No one but me should use method_missing, ever.
          Chef::Log.logger.send(@level, msg)
        end

      end

      def deprecated_ivar(obj, name, level=nil)
        DeprecatedInstanceVariable.new(obj, name, level)
      end

      def deprecated_attr(name, alternative)
        deprecated_attr_reader(name, alternative)
        deprecated_attr_writer(name, alternative)
      end

      def deprecated_attr_reader(name, alternative, level=:warn)
        define_method(name) do
          Chef.log_deprecation("#{self.class}.#{name} is deprecated. Support will be removed in a future release.")
          Chef.log_deprecation(alternative)
          Chef.log_deprecation("Called from:")
          caller[0..3].each {|c| Chef.log_deprecation(c)}
          instance_variable_get("@#{name}")
        end
      end

      def deprecated_attr_writer(name, alternative, level=:warn)
        define_method("#{name}=") do |value|
          Chef.log_deprecation("Writing to #{self.class}.#{name} with #{name}= is deprecated. Support will be removed in a future release.")
          Chef.log_deprecation(alternative)
          Chef.log_deprecation("Called from:")
          caller[0..3].each {|c| Chef.log_deprecation(c)}
          instance_variable_set("@#{name}", value)
        end
      end
    end
  end
end