import Loki from 'lokijs' ; const newDB = ( file ) : Promise < Loki > => { return new Promise ( resolve => { const databaseInitializer = ( ) => { let markers = db . getCollection ( 'markers' ) ; if ( markers === null ) { markers = db . addCollection ( 'markers' ) ; } resolve ( db ) ; } ; const db = new Loki ( file , { autoload : true , autosave : true , autosaveInterval : 4000 , autoloadCallback : databaseInitializer } ) ; } ) ; } ; export default newDB ;