What is the equivalent of jQuery's .before() function in Javascript?

Question

What is the equivalent of .before() in Javascript?

Answer 1

node.insertBefore() is pretty much the equivalent : https://developer.mozilla.org/en-US/docs/Web/API/Node.insertBefore

$('#id').before('something');
//equivalent 
var node = document.getElementById('id');
node.parentNode.insertBefore('something', node);

Here what jQuery does : https://gist.github.com/kagagnon/a13de27760ba1af883c0#file-gistfile1-js-L6064

before: function() {
    return this.domManip( arguments, function( elem ) {
        if ( this.parentNode ) {
            this.parentNode.insertBefore( elem, this );
        }
    });
}