Misago/frontend/src/components/editor/actions/code.js

import React from "react"
import Action from "./action"

export default function(props) {
  return (
    <Action execAction={insertCode} title={gettext("Insert code")} {...props}>
      <span className="material-icon">functions</span>
    </Action>
  )
}

export function insertCode(selection, replace) {
  const syntax = $.trim(
    prompt(gettext("Enter name of syntax of your code (optional)") + ":")
  )
  replace("\n\n```" + syntax + "\n" + selection + "\n```\n\n")
}