1 files changed, 19 insertions, 1 deletions
diff --git a/actionview/test/template/form_helper/form_with_test.rb b/actionview/test/template/form_helper/form_with_test.rb
index ed1683bad2..c30176349c 100644
--- a/actionview/test/template/form_helper/form_with_test.rb
+++ b/actionview/test/template/form_helper/form_with_test.rb
@@ -318,7 +318,8 @@ class FormWithActsLikeFormForTest < FormWithTest
     @url_for_options = object
 
     if object.is_a?(Hash) && object[:use_route].blank? && object[:controller].blank?
-      object.merge!(controller: "main", action: "index")
+      object[:controller] = "main"
+      object[:action] = "index"
     end
 
     super
@@ -464,6 +465,23 @@ class FormWithActsLikeFormForTest < FormWithTest
     end
   end
 
+  def test_form_with_with_collection_select
+    post = Post.new
+    def post.active; false; end
+    form_with(model: post) do |f|
+      concat f.collection_select(:active, [true, false], :to_s, :to_s)
+    end
+
+    expected = whole_form("/posts") do
+      "<select name='post[active]' id='post_active'>" \
+      "<option value='true'>true</option>\n" \
+      "<option selected='selected' value='false'>false</option>" \
+      "</select>"
+    end
+
+    assert_dom_equal expected, output_buffer
+  end
+
   def test_form_with_with_collection_radio_buttons
     post = Post.new
     def post.active; false; end