function validateFirebase(cb) {
  // Ensure FIREBASE_URL is set and valid when building the app.
  if (process.env.FIREBASE_URL === undefined) {
    return cb(new Error('FIREBASE_URL must be set'));
  }
  if (!process.env.FIREBASE_URL.endsWith('firebaseio.com/')) {
    return cb(new Error('FIREBASE_URL must end in firebaseio.com/'));
  }
  return cb();
}
/*.scss',
  vendor: [
    './node_modules/@bower_components/jquery/jquery.js',
    './node_modules/@bower_components/velocity/velocity.js',
    './node_modules/@bower_components/bootstrap-sass-official/assets/javascripts/bootstrap.js',
    './node_modules/@bower_components/underscore/underscore.js',
    './node_modules/@bower_components/backbone/backbone.js',
    './node_modules/@bower_components/backfire/dist/backfire.js',
    './node_modules/@bower_components/backbone.marionette/lib/backbone.marionette.js',
    './app/vendor/jquery_ui/jquery-ui.min.js',
    './app/vendor/ccConfig.js',
    './app/vendor/cocos2d-html5/lib/cocos2d-js-v3.3-beta0.js',
    './app/vendor/aws/aws-sdk.min.js',
    './app/vendor/aws/aws-sdk-mobile-analytics.min.js',
  ],
};

/* Disable autowatch for now (--watch=false conflicts with --watch in Node.js v18+).
gulp.task('autowatch', (cb) => {
  if (opts.watch) {
    autowatch(gulp, watchPaths);
  }
  cb();
});