let published_at = new Date()

  if (published_at) console.log("it's true!")
  if (!published_at) console.log("it's false!")

As a FE dev I haven't had workplace with a codebase allowing above for at least 5 years. No one even asks "shall we us JS ot TS?". Strictly enforced static typing all over. It's not that I like it, just no one asks me.