Android, Compose. How to correctly test animated scroll in compose?

Question

I'm trying to test accompanist PagerState.

The author has already added tests (https://github.com/google/accompanist/blob/main/pager/src/sharedTest/kotlin/com/google/accompanist/pager/PagerStateUnitTest.kt), however he uses scrollToPage, but I need to use animateScrollToPage.

But when i replace the scrollToPage with the animateScrollToPage (change_pager_count test) I get exception:

java.lang.IllegalStateException: A MonotonicFrameClock is not available in this CoroutineContext. Callers should supply an appropriate MonotonicFrameClock using withContext.

I tried to remember coroutine scope and run animateScrollToPage inside this scope:

composeTestRule.setContent {
 scope = rememberCoroutineScope()
.....
}

composeTestRule.runOnIdle {
  scope.launch {
       pagerState.animateScrollToPage(page = 8)
      }
}



// And assert that currentPage and pageCount are correct
assertThat(pagerState.currentPage).isEqualTo(8)
assertThat(pagerState.pageCount).isEqualTo(10)

But I still get this exception.

Please help me figure out what I'm doing wrong.