correctly presence check of `application_record.rb` in plugin

2 files changed, 16 insertions, 1 deletions

diff --git a/activerecord/lib/rails/generators/active_record/model/model_generator.rb b/activerecord/lib/rails/generators/active_record/model/model_generator.rb
index 15aecf28ca..7395839fca 100644
--- a/activerecord/lib/rails/generators/active_record/model/model_generator.rb
+++ b/activerecord/lib/rails/generators/active_record/model/model_generator.rb
@@ -45,7 +45,13 @@ module ActiveRecord
         def determine_default_parent_class
           application_record = nil
 
-          in_root { application_record = File.exist?('app/models/application_record.rb') }
+          in_root do
+            application_record = if mountable_engine?
+              File.exist?("app/models/#{namespaced_path}/application_record.rb")
+            else
+              File.exist?('app/models/application_record.rb')
+            end
+          end
 
           if application_record
             "ApplicationRecord"
diff --git a/railties/test/generators/plugin_generator_test.rb b/railties/test/generators/plugin_generator_test.rb
index bb84df899a..c5723e364d 100644
--- a/railties/test/generators/plugin_generator_test.rb
+++ b/railties/test/generators/plugin_generator_test.rb
@@ -621,6 +621,15 @@ class PluginGeneratorTest < Rails::Generators::TestCase
     assert_no_directory "app/views"
   end
 
+  def test_model_with_existent_application_record_in_mountable_engine
+    run_generator [destination_root, '--mountable']
+    capture(:stdout) do
+      `#{destination_root}/bin/rails g model article`
+    end
+
+    assert_file "app/models/bukkits/article.rb", /class Article < ApplicationRecord/
+  end
+
 protected
   def action(*args, &block)
     silence(:stdout){ generator.send(*args, &block) }