Method "insertBefore" on Element

[kboshold]

On the element there should be a method to insert a new node at a reference within an element. Currently, for example, there is no possibility to insert a node in front of a processing instruction.

Example:

export class Element extends Node {
  // ...

  /**
   * @param {Node} node
   *  Node to insert in front of the passed `reference`
   * @param {Node | null} reference
   * Reference to insert the node. When passing `null` the node will be appended to `this` element. 
   * The passed node has to be a child of this element.
   * @return The original element, not the child.
   */
  insertBefore(node: Node, reference: Node | null): this;
}

May the Node has to be ProcessingInstruction | Text | Element | Comment | null - Otherwise you could try to insert something in front of an Attribute

Usage:

const address = document.get('/address')
const name = address.get('/name');
const marker = address.get('./processing-instruction("marker")');

address.insertBefore(name, marker);