Angular 2 Key Value Pipe

key-value.pipe.ts

import { Pipe, PipeTransform } from '@angular/core';

/*
 * Enables the key/value pair of an item to be
 * visible within an ngFor
 * Usage:
 *   value of iteratable | keyValue
 * Example:
 * <ul>
 *   <li *ngFor='key of demo | keyValue'>
 *   Key: {{key.key}}, value: {{key.value}}
 *   </li>
 * </ul>
*/
@Pipe({ name: 'keyValue' })
export class KeyValuePipe implements PipeTransform {
  transform(value, args: string[]): any {
    let keys = [];
    for (let key in value) {
      keys.push({ key: key, value: value[key]});
    }
    return keys;
  }
}

what about type safety ?

transform<T, U extends { [id: string]: T } | { [id: number]: T }>(value: U, args?: any): { key: keyof U, value: U[keyof U] }[] {
	const keys: {key: keyof U, value: U[keyof U]}[] = [];
	  for (const key in value) {
		keys.push({key: key, value: value[key]});
	  }
	return keys;
  }