Real-life: groupBy() tickets by status

Group tickets by status and output the count in each group.

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const { from, groupBy, mergeMap, toArray, map } = Rx;

const tickets = [
  { status: 'open' },
  { status: 'closed' },
  { status: 'open' },
];

const result$ = from(tickets).pipe(
  groupBy(ticket => ticket.status),
  mergeMap(group$ => group$.pipe(
    toArray(),
    map(items => group$.key + ':' + items.length)
  ))
);

result$.subscribe(value => console.log(value));

script.ts // TypeScript

CONSOLE · Console output

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