Snippets of things I've done once but I'll probably need again

rxjs snippets.ts

/**
* Emit each element of array as single event.
*/
const array$: Subject<string[]> = new Subject<string[]>();

const each$: Observable<string> = array$.pipe(
  tap((v: string[]) => console.log('array', v)),
  switchMap((array: string[]) => merge(...(array.map((item: string) => of(item))))),
  tap((v: string) => console.log('each', v)),
);

each$.subscribe();
array$.next(['a', 'b', 'c']);
// Console:
// array [ 'a', 'b', 'c' ]
// each a
// each b
// each c