How to make an rxjs marble sync grouping only take up one frame

Question

According to https://github.com/ReactiveX/rxjs/blob/master/docs_app/content/guide/testing/marble-testing.md#marble-syntax

'--(abc)-|': on frame 20, emit a, b, and c, then on frame 80 complete

So how do I represent "on frame 20, emit a, b, and c, then on frame 40 complete.

Ie how can I stop the sync group itself taking up frames?

Detribalize

You can't; there's nothing you can do about it. The example from the documentation that you've included in the question describes the TestScheduler's behaviour. – Gilly

Answer 1

cartant has answered this question in his comment.

There's no way to do it - sync groups will always take up extra frames even though all members occur in the frame of the opening bracket.

Detribalize

Just in case this might help anyone else, there's an alternative library that provides this functionality: https://mcmap.net/q/1519980/-how-to-test-observables-which-emit-grouped-events-with-rxjs-marbles – Haymow