Chunking and Slicing Dataset Arrays Using Pure Transformation Pipes

import { Pipe, PipeTransform } from '@angular/core';
 
@Pipe({
  name: 'paginate',
  standalone: true,
  pure: true
})
export class PaginatePipe implements PipeTransform {
  public transform<T>(
    collection: readonly T[] | null | undefined,
    pageIndex: number,
    pageSize: number
  ): T[] {
    if (!Array.isArray(collection) || collection.length === 0) {
      return [];
    }
 
    const sanitizedPageSize = Math.max(1, Math.floor(pageSize));
    const sanitizedPageIndex = Math.max(0, Math.floor(pageIndex));
    const startIndex = sanitizedPageIndex * sanitizedPageSize;
 
    if (startIndex >= collection.length) {
      return [];
    }
 
    return collection.slice(startIndex, startIndex + sanitizedPageSize);
  }
}