store only is_migrated true in migrated .script files

dashboard/app/controllers/scripts_controller.rb

@@ -109,7 +109,7 @@ def edit
       has_course: @script&.unit_groups&.any?,
       i18n: @script ? @script.summarize_i18n_for_edit : {},
       levelKeyList: @script.is_migrated ? Level.key_list : {},
-      lessonLevelData: @script_file,
+      lessonLevelData: @script_dsl_text,
       locales: options_for_locale_select,
       script_families: ScriptConstants::FAMILY_NAMES,
       version_year_options: Script.get_version_year_options,
@@ -190,7 +190,7 @@ def get_rollup_resources
   private
 
   def set_script_file
-    @script_file = ScriptDSL.serialize_lesson_groups(@script)
+    @script_dsl_text = ScriptDSL.serialize_lesson_groups(@script)
   end
 
   def rake

dashboard/app/dsl/script_dsl.rb

@@ -320,6 +320,9 @@ def self.serialize(script, filename)
   end
 
   def self.serialize_to_string(script)
+    # the serialized data for migrated scripts lives in the .script_json file
+    return "is_migrated true\n" if script.is_migrated
+
     s = []
     # Legacy script IDs
     legacy_script_ids = {
@@ -361,7 +364,6 @@ def self.serialize_to_string(script)
     s << 'deprecated true' if script.deprecated
     s << 'is_course true' if script.is_course
     s << "background '#{script.background}'" if script.background
-    s << 'is_migrated true' if script.is_migrated
 
     s << '' unless s.empty?
     s << serialize_lesson_groups(script)

dashboard/app/models/script.rb

@@ -1261,12 +1261,14 @@ def update_text(script_params, script_text, metadata_i18n, general_params)
     begin
       if Rails.application.config.levelbuilder_mode
         script = Script.find_by_name(script_name)
-        # Save in our custom Script DSL format. This is still what we're using currently to sync data
-        # across environments. The CPlat team is working on replacing it a new JSON-based approach.
+        # Save in our custom Script DSL format. This is how we currently sync
+        # data across environments for non-migrated scripts.
         script.write_script_dsl
 
-        # Also save in JSON format for "new seeding". This has not been launched yet for most scripts, but as part of
-        # pre-launch testing, we'll start generating these files in addition to the old .script files.
+        # Also save in JSON format for "new seeding". This is how we currently
+        # sync data across environments for migrated scripts. As part of
+        # pre-launch testing, we also generate these files for legacy scripts in
+        # addition to the old .script files.
         script.write_script_json
       end
       true

dashboard/test/dsl/script_dsl_test.rb

@@ -901,13 +901,7 @@ def setup
       }
     script_text = ScriptDSL.serialize_to_string(script)
     expected = <<~SCRIPT
-      hidden false
-      new_name 'new name'
-      family_name 'family name'
-      version_year '2001'
-      is_course true
       is_migrated true
-
     SCRIPT
     assert_equal expected, script_text
   end