Production & Dev instance warning

Warns you if you are on the dev or prod instance of your web app (not on localhost)

You will need to install an extension such as Tampermonkey, Greasemonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Userscripts to install this script.

You will need to install an extension such as Tampermonkey to install this script.

You will need to install a user script manager extension to install this script.

(I already have a user script manager, let me install it!)

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

(I already have a user style manager, let me install it!)

// ==UserScript==
// @name         Production & Dev instance warning
// @namespace    ahappyviking
// @version      1.0.0
// @description  Warns you if you are on the dev or prod instance of your web app (not on localhost)
// @match        https://*.[APP NAME HERE].com/*
// @icon         https://i.kym-cdn.com/entries/icons/original/000/027/475/Screen_Shot_2018-10-25_at_11.02.15_AM.png
// @grant        none
// ==/UserScript==

const main = () => {
    const elem = document.createElement('div')
    elem.style.position = "fixed"
    elem.style.left = 0
    elem.style.right = 0
    elem.style.top = 0
    elem.style.height = "14px"
    elem.style.fontSize = "10px"
    elem.style.cursor = "pointer"
    elem.style.zIndex = 99999
    elem.style.fontWeight = "bold"
    elem.style.textAlign = "center"
    elem.addEventListener("click", () => (elem.style.display = "none"))
    document.body.appendChild(elem)
      
    if (window.location.hostname.startsWith("dev")){
      elem.style.backgroundColor = "#04d9ff"
      elem.innerText = "NOT ON LOCALHOST - DEV"
    }else{
      elem.style.backgroundColor = "yellow"
      elem.innerText = "NOT ON LOCALHOST - PRODUCTION"
    }
  }
  
  main()