1 files changed, 7 insertions, 3 deletions
diff --git a/railties/lib/rails/test_unit/reporter.rb b/railties/lib/rails/test_unit/reporter.rb
index fe11664d5e..ab28034d27 100644
--- a/railties/lib/rails/test_unit/reporter.rb
+++ b/railties/lib/rails/test_unit/reporter.rb
@@ -3,8 +3,7 @@ require "minitest"
 
 module Rails
   class TestUnitReporter < Minitest::StatisticsReporter
-    class_attribute :executable
-    self.executable = "bin/rails test"
+    class_attribute :executable, default: "bin/rails test"
 
     def record(result)
       super
@@ -72,7 +71,12 @@ module Rails
       end
 
       def app_root
-        @app_root ||= defined?(ENGINE_ROOT) ? ENGINE_ROOT : Rails.root
+        @app_root ||=
+          if defined?(ENGINE_ROOT)
+            ENGINE_ROOT
+          elsif Rails.respond_to?(:root)
+            Rails.root
+          end
       end
 
       def colored_output?