mergeStream = require('merge-stream'); const swPrecacheConfig = require(path.join(__dirname, '..', '..', 'sw-precache-config.js')); const project = new PolymerProject(require(path.join(__dirname, '..', '..', 'polymer.json'))); gulp.task('deploy.addServiceWorker', ['deploy.stream'], () => { return addServiceWorker({ buildRoot: dist(), project: project, swPrecacheConfig: swPrecacheConfig, }); }); gulp.task('deploy.stream', () => { return mergeStream(project.sources(), project.dependencies()); });