Method splice

packages/core/src/lib/list-unit.ts:541–558

* Removes items from the list-value and, if necessary, * inserts new items in their place, returning the deleted items. \ * Dispatches a new copy of the value, without mutating the current-value. * * It only works if the Unit is not frozen, and \ * either deleteCount is not 0

(start: number, deleteCount: number, ...items: Item[])

   * @category Customised Array.prototype
   */
  splice(start: number, deleteCount: number, ...items: Item[]): Item[] {
    // tslint:disable-next-line:triple-equals
    if (this.isFrozen || ((deleteCount == 0 || this.isEmpty) && !items.length)) {
      return [];
    }
    this.checkSerializabilityMaybe(items);

    const listShallowCopy = [...this.rawValue()];
    const removedItems = this.deepCopyMaybe(
      listShallowCopy.splice(start, deleteCount, ...items.map(item => this.deepCopyMaybe(item)))
    );
    this.updateValueAndCache(listShallowCopy);

    if (this.eventsSubject?.observers.length && !this.isMuted) {
      this.eventsSubject.next(new EventListUnitSplice(start, deleteCount, removedItems, items));
    }
    return removedItems;
  }

  /**
   * Fills a section of the list-{@link value} with provided param `item`. \