1 files changed, 34 insertions, 0 deletions
diff --git a/actionview/test/template/controller_helper_test.rb b/actionview/test/template/controller_helper_test.rb
new file mode 100644
index 0000000000..46d20c188c
--- /dev/null
+++ b/actionview/test/template/controller_helper_test.rb
@@ -0,0 +1,34 @@
+# frozen_string_literal: true
+
+require "abstract_unit"
+
+class ControllerHelperTest < ActionView::TestCase
+  tests ActionView::Helpers::ControllerHelper
+
+  class SpecializedFormBuilder < ActionView::Helpers::FormBuilder ; end
+
+  def test_assign_controller_sets_default_form_builder
+    @controller = OpenStruct.new(default_form_builder: SpecializedFormBuilder)
+    assign_controller(@controller)
+
+    assert_equal SpecializedFormBuilder, default_form_builder
+  end
+
+  def test_assign_controller_skips_default_form_builder
+    @controller = OpenStruct.new
+    assign_controller(@controller)
+
+    assert_nil default_form_builder
+  end
+
+  def test_respond_to
+    @controller = OpenStruct.new
+    assign_controller(@controller)
+    assert_not respond_to?(:params)
+    assert respond_to?(:assign_controller)
+
+    @controller.params = {}
+    assert respond_to?(:params)
+    assert respond_to?(:assign_controller)
+  end
+end