const Migrations0DatabaseWithAttachmentData = require('./migrations_0_database_with_attachment_data'); const Migrations1DatabaseWithoutAttachmentData = require('./migrations_1_database_without_attachment_data'); exports.getPlaceholderMigrations = () => { const last0MigrationVersion = Migrations0DatabaseWithAttachmentData.getLatestVersion(); const last1MigrationVersion = Migrations1DatabaseWithoutAttachmentData.getLatestVersion(); const lastMigrationVersion = last1MigrationVersion || last0MigrationVersion; return [ { version: lastMigrationVersion, migrate() { throw new Error( 'Unexpected invocation of placeholder migration!' + '\n\nMigrations must explicitly be run upon application startup instead' + ' of implicitly via Backbone IndexedDB adapter at any time.' ); }, }, ]; };