el-arroyo-jquery.js

function $(selector) {

  const element = typeof selector === 'string' 
    ? document.querySelector(selector)
    : selector

  return {
      addClass(className) {
        element.classList.add(className)
        return this
      },
      removeClass(className) {
        element.classList.remove(className)
        return this
      },
      attr(name, value) {
        element.setAttribute(name, value)
        return this
      },
      on(event, callback) {
        element.addEventListener(event, callback)
        return this
      }
    }
}

$(".button").on("click", function() {
  $(this).addClass("active").attr("disabled", true)
})