"When using log, line ChartJS empty / null values doesn't break the line"

[wolwemaan]

Expected Behavior

When encountering NaN / empty / null values the ChartJS line should be broken similar as when a non logarithmic type is selected.

Current Behavior

When using the logarithmic type in chart, the ChartJS line doesn't get broken as expected when encountering NaN / empty / null values, instead it is defaulted to 0

Possible Solution

Version 3 may provide a fix but at the moment a suggestion to resolve for version 2.9.4 is required,

Steps to Reproduce

https://codepen.io/wolwemaan/pen/ZEOmJdz

Context

Switching the y axis to type logarithmic causes the empty values to be charted as 0

Environment

• Chart.js version: 2.9.4
• Browser name and version: Chromium Version 86.0.4240.183 (Official Build) snap (64-bit)
• Link to your project:

[wolwemaan]

https://pasteboard.co/JzLUj2S.png

Attaching an image highlighting the unexpected 0's that is being charted

[wolwemaan]

I got a non-ideal workaround by skipping NaN values altogether. Non-ideal since it results in the x-bar being updated accordingly

[etimberg]

V3 will skip the NaNs by default, but that still causes X axis problems. The root cause of NaNs being skipped is the check for isNaN(otherValue) in https://github.com/chartjs/Chart.js/blob/master/src/core/core.datasetController.js#L609. The simplest solution would be to add an explicit max to the x axis.

https://codepen.io/etimberg/pen/QWGwgGQ?editors=1000