prosemirror-flat-list/src/utils/list-range.ts

Powerful list support for ProseMirror

import { NodeRange, type ResolvedPos } from 'prosemirror-model'

import { isListNode } from './is-list-node'

/**
 * Returns a minimal block range that includes the given two positions and
 * represents one or multiple sibling list nodes.
 *
 * @public
 */
export function findListsRange(
  $from: ResolvedPos,
  $to: ResolvedPos = $from,
): NodeRange | null {
  if ($to.pos < $from.pos) {
    return findListsRange($to, $from)
  }

  let range = $from.blockRange($to)

  while (range) {
    if (isListsRange(range)) {
      return range
    }

    if (range.depth <= 0) {
      break
    }

    range = new NodeRange($from, $to, range.depth - 1)
  }

  return null
}

/** @internal */
export function isListsRange(range: NodeRange): boolean {
  const { startIndex, endIndex, parent } = range

  for (let i = startIndex; i < endIndex; i++) {
    if (!isListNode(parent.child(i))) {
      return false
    }
  }

  return true
}