tiptap/packages/core/src/utilities/removeDuplicates.ts

/**
 * Removes duplicated values within an array.
 * Supports numbers, strings and objects.
 */
export function removeDuplicates<T>(array: T[], by = JSON.stringify): T[] {
  const seen: Record<any, any> = {}

  return array.filter(item => {
    const key = by(item)

    return Object.prototype.hasOwnProperty.call(seen, key)
      ? false
      : (seen[key] = true)
  })
}