Add AC::Parameters#to_unsafe_h

As suggested in #16299([1]), this method should be a new public API for
retrieving unfiltered parameters from `ActionController::Parameters`
object, given that `Parameters#to_hash` will no longer work in Rails
5.0+ as we stop inheriting `Parameters` from `Hash`.

[1]: https://github.com/rails/rails/pull/16299#issuecomment-50220919

2 files changed, 12 insertions, 0 deletions

diff --git a/actionpack/lib/action_controller/metal/strong_parameters.rb b/actionpack/lib/action_controller/metal/strong_parameters.rb
index a5ee1e2159..9a99bd2001 100644
--- a/actionpack/lib/action_controller/metal/strong_parameters.rb
+++ b/actionpack/lib/action_controller/metal/strong_parameters.rb
@@ -163,6 +163,12 @@ module ActionController
       end
     end
 
+    # Returns an unsafe, unfiltered +Hash+ representation of this parameter.
+    def to_unsafe_h
+      to_hash
+    end
+    alias_method :to_unsafe_hash, :to_unsafe_h
+
     # Convert all hashes in values into parameters, then yield each pair like
     # the same way as <tt>Hash#each_pair</tt>
     def each_pair(&block)
diff --git a/actionpack/test/controller/parameters/parameters_permit_test.rb b/actionpack/test/controller/parameters/parameters_permit_test.rb
index ba98ad7605..2ed486516d 100644
--- a/actionpack/test/controller/parameters/parameters_permit_test.rb
+++ b/actionpack/test/controller/parameters/parameters_permit_test.rb
@@ -280,4 +280,10 @@ class ParametersPermitTest < ActiveSupport::TestCase
 
     assert_equal({ "controller" => "users", "action" => "create" }, params.to_h)
   end
+
+  test "to_unsafe_h returns unfiltered params" do
+    assert @params.to_h.is_a? Hash
+    assert_not @params.to_h.is_a? ActionController::Parameters
+    assert_equal @params.to_hash, @params.to_unsafe_h
+  end
 end