Error bar domain ignore null

[rinkstiekema]

Duplicate of this PR. I made this PR to also have this fix available in v2.x. Hope this is the correct way!

Description

The entry value for an error bar receives the default value 0 in case it was null. This would cause the domain to be calculated incorrectly, as 0 may not be a value in the data array.

When using error bars, the domain accounts for any potential in the error values. Error values are expressed relative to the main entry value. In case the main entry value is nullish, its default value would be 0. This may not be a value in the actual data.

Related Issue

No known related issues yet

Motivation and Context

Given this example data:

const data = [
  { x: 1, y: 200, errorY: [10, 10] },
  { x: 1, y: 300, errorY: [10, 10] },
  { x: 1, y: 400, errorY: [10, 10] },
]

The min value of the y-axis domain would be:
[min(y - errorY[0]), max(y + errorY[1])] = [200 - 10, 400 + 10] = [190, 410]

Now consider this other example:

const data = [
  { x: 1, y: 200, errorY: [10, 10] },
  { x: 1, y: null, errorY: [10, 10] },
  { x: 1, y: 400, errorY: [10, 10] },
]

The current implementation would report:
[min(y - errorY[0]), max(y + errorY[1])] = [0 - 10, 400 + 10] = [-10, 410]
While the expected behaviour is:
[min(y - errorY[0]), max(y + errorY[1])] = [200 - 10, 400 + 10] = [190, 410]

Some codesandbox examples can be found here.

How Has This Been Tested?

I have added unit tests for the domain creation.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• I have added a storybook story or extended an existing story to show my changes
• All new and existing tests passed.

[PavelVanecek]

Appreciate the tests!