1 files changed, 9 insertions, 1 deletions
diff --git a/activesupport/test/deprecation_test.rb b/activesupport/test/deprecation_test.rb
index f2267a822f..105153584d 100644
--- a/activesupport/test/deprecation_test.rb
+++ b/activesupport/test/deprecation_test.rb
@@ -158,7 +158,7 @@ class DeprecationTest < ActiveSupport::TestCase
     stderr_output = capture(:stderr) {
       assert_nil behavior.call("Some error!", ["call stack!"], "horizon", "gem")
     }
-    assert stderr_output.empty?
+    assert_empty stderr_output
   end
 
   def test_default_notify_behavior
@@ -182,6 +182,14 @@ class DeprecationTest < ActiveSupport::TestCase
     end
   end
 
+  def test_default_invalid_behavior
+    e = assert_raises(ArgumentError) do
+      ActiveSupport::Deprecation.behavior = :invalid
+    end
+
+    assert_equal ":invalid is not a valid deprecation behavior.", e.message
+  end
+
   def test_deprecated_instance_variable_proxy
     assert_not_deprecated { @dtc.request.size }