Path.js

'use strict';
const {
  COMMENT_NODE,
  DOCUMENT_FRAGMENT_NODE,
  ELEMENT_NODE
} = require('../shared/constants.js');

// every template literal interpolation indicates
// a precise target in the DOM the template is representing.
// `<p id=${'attribute'}>some ${'content'}</p>`
// hyperHTML finds only once per template literal,
// hence once per entire application life-cycle,
// all nodes that are related to interpolations.
// These nodes are stored as indexes used to retrieve,
// once per upgrade, nodes that will change on each future update.
// A path example is [2, 0, 1] representing the operation:
// node.childNodes[2].childNodes[0].childNodes[1]
// Attributes are addressed via their owner node and their name.
const createPath = node => {
  const path = [];
  let parentNode;
  switch (node.nodeType) {
    case ELEMENT_NODE:
    case DOCUMENT_FRAGMENT_NODE:
      parentNode = node;
      break;
    case COMMENT_NODE:
      parentNode = node.parentNode;
      prepend(path, parentNode, node);
      break;
    default:
      parentNode = node.ownerElement;
      break;
  }
  for (
    node = parentNode;
    (parentNode = parentNode.parentNode);
    node = parentNode
  ) {
    prepend(path, parentNode, node);
  }
  return path;
};

const prepend = (path, parent, node) => {
  path.unshift(path.indexOf.call(parent.childNodes, node));
};

Object.defineProperty(exports, '__esModule', {value: true}).default = {
  create: (type, node, name) => ({type, name, node, path: createPath(node)}),
  find: (node, path) => {
    const length = path.length;
    for (let i = 0; i < length; i++) {
      node = node.childNodes[path[i]];
    }
    return {node, childNodes: []};
  }
}