Prettier 1.19.1
Playground link

--parser babel
--print-width 100
--single-quote

Input:

stream1$.pipe(
  withLatestFrom(stream2$),
  distinctUntilChanged(),
  debounceTime(50)
)

Output:

stream1$.pipe(withLatestFrom(stream2$), distinctUntilChanged(), debounceTime(50));

Expected behavior:
Function literal heuristic introduced in #6033 is insufficient for RxJS, since it ignores a lot of operators which at their core are functional compositions, but not in syntax. I don't have a solution proposal, but it's breaking existing (and expected) behavior right now.