diff --git a/activestorage/test/javascript_package_test.rb b/activestorage/test/javascript_package_test.rb
new file mode 100644
index 0000000000..c0216e0704
--- /dev/null
+++ b/activestorage/test/javascript_package_test.rb
@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+require "test_helper"
+
+class JavascriptPackageTest < ActiveSupport::TestCase
+  def test_compiled_code_is_in_sync_with_source_code
+    compiled_file = File.expand_path("../app/assets/javascripts/activestorage.js", __dir__)
+
+    assert_no_changes -> { File.read(compiled_file) } do
+      system "yarn build"
+    end
+  end
+end