how obfuscat entire folder js file using gulpfile.js

"Here is my gulpfile.js please let me know what should i have to add in this file to obfuscat all js files"

const gulp = require("gulp");
const minify = require("gulp-minify");
const JavaScriptObfuscator = require("javascript-obfuscator");

  gulp.task("js", function () {
  return gulp
  .src("js/*.js")
  .pipe(gulp.dest("output/"));
});