@atlaskit/editor-plugin-selection-extension/dist/es2019/pm-plugins/utils/getOffsetByPath.js

editor-plugin-selection-extension plugin for @atlaskit/editor-core

import { Fragment, Node as PMNode } from '@atlaskit/editor-prosemirror/model';

// TODO: ED-28434 - move this to a shared package
// mirror code from https://bitbucket.org/atlassian/pf-adf-service/src/master/src/lib/update/get-offset.ts

export function getOffsetByPath(root, pos, pointer, from = 0, to) {
  const parts = pointer.split('/');
  let ref = root;
  const len = parts.length;
  // -1 to account for the root node (usually doc)
  // The start of the document, right before the first content, is position 0.
  let offset = pos; //-1;

  for (let i = 1; i < len; i++) {
    const key = parts[i];
    // @ts-ignore - TS1501 TypeScript 5.9.2 upgrade
    if (ref instanceof Fragment && /^[0-9]+$/u.test(key)) {
      let index = parseInt(key, 10);
      if (index >= ref.childCount) {
        throw new Error(`JSON pointer "${pointer}" points to non-existing location.`);
      }
      const nextRef = ref.child(index);
      while (index--) {
        offset += ref.child(index).nodeSize;
      }
      ref = nextRef;
    } else if (ref instanceof PMNode) {
      /**
       * Reference: https://prosemirror.net/docs/guide/#doc.data_structures
       * +----------------------------------+
       * |              Node                |
       * |              ^^^^                |
       * | type:       NodeType             |
       * | content:    Fragment             |
       * |              [ Node, Node, ...]  |
       * | attrs:      Object               |
       * | marks:      Mark                 |
       * |              [                   |
       * |                type: MarkType    |
       * |                attrs: Object     |
       * |              ]                   |
       * +----------------------------------+
       */
      switch (key) {
        case 'content':
          // Entering or leaving a node that is not a leaf node (i.e. supports content) counts as one token.
          offset++;
          ref = ref.content;
          break;
        case 'attrs':
          return {
            type: 'attrs',
            from: offset + from,
            path: parts.slice(i + 1)
          };
        case 'text':
          if (!ref.isText) {
            throw new Error(`"${parts.slice(0, i).join('/')}" doesn't have any "text" node!`);
          }
          continue;
        default:
          throw new Error(`JSON pointer "${pointer}" points to an unsupported location.`);
      }
    } else {
      throw new Error(`JSON pointer "${pointer}" points to an unsupported entity.`);
    }
  }
  if (ref instanceof Fragment) {
    throw new Error(`Expected a Node, but the JSON pointer "${pointer}" points to a Fragment.`);
  }
  return {
    type: 'node',
    from: offset + from,
    to: offset + (to !== null && to !== void 0 ? to : ref.nodeSize),
    matches: [to ? ref.textBetween(from, to) : ref.textContent]
  };
}