Function normalizeInsertDelta

packages/yjs-transform/src/delta.ts:5–33

(delta: InsertDelta)

import { deepEquals } from './object'

export function normalizeInsertDelta(delta: InsertDelta): InsertDelta {
  const normalized: InsertDelta = []

  for (const element of delta) {
    if (typeof element.insert === 'string' && element.insert.length === 0) {
      continue
    }

    const prev = normalized[normalized.length - 1]
    if (!prev || typeof prev.insert !== 'string' || typeof element.insert !== 'string') {
      normalized.push(element)
      continue
    }

    const merge =
      prev.attributes === element.attributes ||
      (!prev.attributes === !element.attributes &&
        deepEquals(prev.attributes ?? {}, element.attributes ?? {}))

    if (merge) {
      prev.insert += element.insert
      continue
    }

    normalized.push(element)
  }

  return normalized
}

export function yTextToInsertDelta(yText: Y.XmlText): InsertDelta {
  return normalizeInsertDelta(yText.toDelta()) as InsertDelta