Add a test-case for GH #13825

railties/test/app_rails_loader_test.rb

@@ -22,8 +22,14 @@ def expects_exec(exe)
     exe = "#{script_dir}/rails"
 
     test "is not in a Rails application if #{exe} is not found in the current or parent directories" do
-      File.stubs(:exist?).with('bin/rails').returns(false)
-      File.stubs(:exist?).with('script/rails').returns(false)
+      File.stubs(:file?).with('bin/rails').returns(false)
+      File.stubs(:file?).with('script/rails').returns(false)
+
+      assert !Rails::AppRailsLoader.exec_app_rails
+    end
+
+    test "is not in a Rails application if #{exe} exists but is a folder" do
+      FileUtils.mkdir_p(exe)
 
       assert !Rails::AppRailsLoader.exec_app_rails
     end