append-snippet
A function that synchronously injects a snippet of markup into an HTML document, immediately before the closing </body> tag.
var appendSnippet = ; var html = '<body>\n<h1>hello!</h1>\ndemo\n</body>'; var result = ;// <body>\n<h1>hello!</h1>\ndemo\n<script>alert("cods")</script></body>If there's no closing body tag, it goes just before the </html>, or failing that, the end of the string.