[TSVB] Fix wrongly display stacked as percentage charts

[markov00]

Summary

This PR fix an issue with stack as percentage charts in TSVB by upgrading the @elastic/charts library to 18.2.2 the patch version that solves this issue: elastic/elastic-charts#617

Fix #62419

In this fix, when rendering a stacked area chart in percentage mode, if we have all values as 0 in a bucket, the chart will render a 0% data point for all the series.
Only in case where the values are nulls it will completely disconnect the line/area points where we found the not defined value.

@elastic/charts upgrade procedure

[elasticmachine]

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

[flash1293]

ACK, reviewing now.

[timroes]

Tested on Chrome Linux with given sample data. Fixes the issue. Code LGTM

[flash1293]

The problem seems fixed, but there is a difference in how gaps are treated in TSVB (compared to 7.6.1). Not sure whether that was intended

7.6.1:

This PR:

[timroes]

I think the new behavior looks more appropriate to me, and also should match what we're doing in visualize editor in percentage mode. If we want to stick more closely to the previous behavior I think we could use Fit.LINEAR instead on the chart? That would at least highlight that those parts are not real values actually but just interpolated.

[flash1293]

Good suggestion @timroes - changing the interpolation mode for all TSVB visualizations seems like a confusing change for people used to the old behavior. Just a nit though, IMHO we can also address this later (and give the user control over interpolation while we are at it).

[markov00]

@flash1293 @timroes I will push another change in the elastic-chart to fix this behavior.
I've checked in version 7.4 and, where we have 3 series stacked in percentage mode with all 3 values at 0, the resulting chart brings down to 0% the total percentage. In 7.6 the chart wrongly represents the data because we are tracing a line that interpolates between the previous and next point, misrepresenting the 0 value.
I will fix that in ECH to consider that a 0% bucket and push another commit here

[kibanamachine]

💚 Build Succeeded

• continuous-integration/kibana-ci/pull-request
• Commit: 874a79f

History

• 💚 Build #39187 succeeded e87b5ab
• 💚 Build #38969 succeeded 43abecc

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@elasticmachine merge upstream

[spalger]

Shared deps upgrade LGTM

[flash1293]

Approving retroactively, tested and the new behavior looks good to me 👍 Sorry for the delay