1 files changed, 87 insertions, 1 deletions

diff --git a/actionpack/lib/action_controller/metal/strong_parameters.rb b/actionpack/lib/action_controller/metal/strong_parameters.rb
index d304dcf468..0217376ab3 100644
--- a/actionpack/lib/action_controller/metal/strong_parameters.rb
+++ b/actionpack/lib/action_controller/metal/strong_parameters.rb
@@ -112,6 +112,77 @@ module ActionController
 
     cattr_accessor :action_on_unpermitted_parameters, instance_accessor: false
 
+    ##
+    # :method: as_json
+    #
+    # :call-seq:
+    #   as_json(options=nil)
+    #
+    # Returns a hash that can be used as the JSON representation for the parameters.
+
+    ##
+    # :method: empty?
+    #
+    # :call-seq:
+    #   empty?()
+    #
+    # Returns true if the parameters have no key/value pairs.
+
+    ##
+    # :method: has_key?
+    #
+    # :call-seq:
+    #   has_key?(key)
+    #
+    # Returns true if the given key is present in the parameters.
+
+    ##
+    # :method: has_value?
+    #
+    # :call-seq:
+    #   has_value?(value)
+    #
+    # Returns true if the given value is present for some key in the parameters.
+
+    ##
+    # :method: include?
+    #
+    # :call-seq:
+    #   include?(key)
+    #
+    # Returns true if the given key is present in the parameters.
+
+    ##
+    # :method: key?
+    #
+    # :call-seq:
+    #   key?(key)
+    #
+    # Returns true if the given key is present in the parameters.
+
+    ##
+    # :method: keys
+    #
+    # :call-seq:
+    #   keys()
+    #
+    # Returns a new array of the keys of the parameters.
+
+    ##
+    # :method: value?
+    #
+    # :call-seq:
+    #   value?(value)
+    #
+    # Returns true if the given value is present for some key in the parameters.
+
+    ##
+    # :method: values
+    #
+    # :call-seq:
+    #   values()
+    #
+    # Returns a new array of the values of the parameters.
     delegate :keys, :key?, :has_key?, :values, :has_value?, :value?, :empty?, :include?,
       :as_json, to: :@parameters
 
@@ -589,6 +660,21 @@ module ActionController
       self
     end
 
+    # Returns a new <tt>ActionController::Parameters</tt> with all keys from
+    # current hash merged into +other_hash+.
+    def reverse_merge(other_hash)
+      new_instance_with_inherited_permitted_status(
+        other_hash.to_h.merge(@parameters)
+      )
+    end
+
+    # Returns current <tt>ActionController::Parameters</tt> instance with
+    # current hash merged into +other_hash+.
+    def reverse_merge!(other_hash)
+      @parameters.merge!(other_hash.to_h) { |key, left, right| left }
+      self
+    end
+
     # This is required by ActiveModel attribute assignment, so that user can
     # pass +Parameters+ to a mass assignment methods in a model. It should not
     # matter as we are using +HashWithIndifferentAccess+ internally.
@@ -862,7 +948,7 @@ module ActionController
   #     end
   #
   #     # This will pass with flying colors as long as there's a person key in the
-  #     # parameters, otherwise it'll raise an ActionController::MissingParameter
+  #     # parameters, otherwise it'll raise an ActionController::ParameterMissing
   #     # exception, which will get caught by ActionController::Base and turned
   #     # into a 400 Bad Request reply.
   #     def update