Add aliases for reverse_merge to with_defaults

In the context of controller parameters, reverse_merge is commonly used
to provide defaults for user input. Having an alias to reverse_merge
called with_defaults feels more idiomatic for Rails.

1 files changed, 16 insertions, 0 deletions

diff --git a/actionpack/test/controller/parameters/parameters_permit_test.rb b/actionpack/test/controller/parameters/parameters_permit_test.rb
index 9f3025587e..3e067314d6 100644
--- a/actionpack/test/controller/parameters/parameters_permit_test.rb
+++ b/actionpack/test/controller/parameters/parameters_permit_test.rb
@@ -310,6 +310,14 @@ class ParametersPermitTest < ActiveSupport::TestCase
     refute_predicate merged_params[:person], :empty?
   end
 
+  test "#with_defaults is an alias of reverse_merge" do
+    default_params = ActionController::Parameters.new(id: "1234", person: {}).permit!
+    merged_params = @params.with_defaults(default_params)
+
+    assert_equal "1234", merged_params[:id]
+    refute_predicate merged_params[:person], :empty?
+  end
+
   test "not permitted is sticky beyond reverse_merge" do
     refute_predicate @params.reverse_merge(a: "b"), :permitted?
   end
@@ -327,6 +335,14 @@ class ParametersPermitTest < ActiveSupport::TestCase
     refute_predicate @params[:person], :empty?
   end
 
+  test "#with_defaults! is an alias of reverse_merge!" do
+    default_params = ActionController::Parameters.new(id: "1234", person: {}).permit!
+    @params.with_defaults!(default_params)
+
+    assert_equal "1234", @params[:id]
+    refute_predicate @params[:person], :empty?
+  end
+
   test "modifying the parameters" do
     @params[:person][:hometown] = "Chicago"
     @params[:person][:family] = { brother: "Jonas" }