pseudo coded gulp helper function

gulpfile.js

function buildJs () {
  // bify returns a vinyl-source-stream wrapped browserify bundle
  var browserified = bify();

  return gulp.src(SRC.js)
    .pipe(browserified)
    .pipe(size());
}

gulp.task('js', function () {
  return buildJs()
    .pipe('dist');
});

gulp.task('js:production', function () {
  return buildJs()
    .pipe(uglify())
    .pipe(size())
    .pipe('dist');
});