Failing test: Chrome X-Pack UI Functional Tests.x-pack/test/functional/apps/lens/smokescreen·ts - lens app lens smokescreen tests should show value labels on bar charts when enabled

[kibanamachine]

A test failed on a tracked branch

Error: expected [] to sort of not equal 0
    at Assertion.assert (/dev/shm/workspace/parallel/19/kibana/packages/kbn-expect/expect.js:100:11)
    at Assertion.eql (/dev/shm/workspace/parallel/19/kibana/packages/kbn-expect/expect.js:244:8)
    at Context.<anonymous> (test/functional/apps/lens/smokescreen.ts:242:45)
    at runMicrotasks (<anonymous>)
    at processTicksAndRejections (internal/process/task_queues.js:93:5)
    at Object.apply (/dev/shm/workspace/parallel/19/kibana/packages/kbn-test/src/functional_test_runner/lib/mocha/wrap_function.js:73:16) {
  actual: [],
  expected: 0,
  showDiff: true
}

First failure: Jenkins Build

[elasticmachine]

Pinging @elastic/kibana-app (Team:KibanaApp)

[flash1293]

This only happened once in total so far - it's hard to tell what's going on because it's so rare. I would guess in some cases the DOM isn't updated yet. We are using waitUntilLoadingHasFinished to check whether loading is finished, but if the timing is bad, it's possible the next assertion is done before the DOM is updated. As it's not really possible to reliably determine this (there are a lot of async layers in our rendering pipeline), we could introduce a small wait time (maybe 500ms or something) after the loading indicator has disappeared and put it in a helper like lensPage.waitForVisualizationUpdate() which is used in all of the places waitUntilLoadingHasFinished is used directly right now.

Discussed offline and in visualize we have data-rendering-count and wait until it stops increasing. We can do the same logic in Lens.