add tests to make sure deprecated API is still supported

2 files changed, 14 insertions, 2 deletions

diff --git a/actionview/lib/action_view/base.rb b/actionview/lib/action_view/base.rb
index fe9f3f9503..b143e13c96 100644
--- a/actionview/lib/action_view/base.rb
+++ b/actionview/lib/action_view/base.rb
@@ -224,10 +224,12 @@ module ActionView #:nodoc:
 
     # :startdoc:
 
-    def initialize(renderer, assigns = {}, controller = nil, formats = NULL) #:nodoc:
+    def initialize(renderer = nil, assigns = {}, controller = nil, formats = NULL) #:nodoc:
       @_config = ActiveSupport::InheritableOptions.new
 
-      unless formats == NULL
+      if formats == NULL
+        formats = nil
+      else
         ActiveSupport::Deprecation.warn <<~eowarn
         Passing formats to ActionView::Base.new is deprecated
         eowarn
diff --git a/actionview/test/template/render_test.rb b/actionview/test/template/render_test.rb
index ab67423ea1..76ffe3415d 100644
--- a/actionview/test/template/render_test.rb
+++ b/actionview/test/template/render_test.rb
@@ -336,6 +336,16 @@ module RenderTestCases
     assert_equal "Hello: davidHello: mary", @view.render(partial: "test/customer", collection: customers)
   end
 
+  def test_deprecated_constructor
+    assert_deprecated do
+      ActionView::Base.new
+    end
+
+    assert_deprecated do
+      ActionView::Base.new ["/a"]
+    end
+  end
+
   def test_render_partial_without_object_does_not_put_partial_name_to_local_assigns
     assert_equal "false", @view.render(partial: "test/partial_name_in_local_assigns")
   end