matcher_delegator.rb in rspec-expectations-3.13.0

- old
+ new

@@ -1,9 +1,35 @@
 module RSpec
   module Matchers
+    # Provides a base class with as little methods as possible, so that
+    # most methods can be delegated via `method_missing`.
+    #
+    # On Ruby 2.0+ BasicObject could be used for this purpose, but it
+    # introduce some extra complexity with constant resolution, so the
+    # BlankSlate pattern was prefered.
+    # @private
+    class BaseDelegator
+      kept_methods = [
+        # Methods that raise warnings if removed.
+        :__id__, :__send__, :object_id,
+
+        # Methods that are explicitly undefined in some subclasses.
+        :==, :===,
+
+        # Methods we keep on purpose.
+        :class, :respond_to?, :__method__, :method, :dup,
+        :clone, :initialize_dup, :initialize_copy, :initialize_clone,
+      ]
+      instance_methods.each do |method|
+        unless kept_methods.include?(method.to_sym)
+          undef_method(method)
+        end
+      end
+    end
+
     # Provides the necessary plumbing to wrap a matcher with a decorator.
     # @private
-    class MatcherDelegator
+    class MatcherDelegator < BaseDelegator
       include Composable
       attr_reader :base_matcher
 
       def initialize(base_matcher)
         @base_matcher = base_matcher