fix: dedup data for <VictoryStack/>

[r281GQ]

Description

That is a tricky issue. The problem is with AreaCharts (or LineCharts) when we use them in stacked mode.

We opt-in for stack mode by wrapping the Chart in the <VictoryStack /> component.

VictoryStack modifies the underlying data which makes AreaChart behave a bit different (draws different area) compared to when it's used on it's own. Only when given invalid data.

What is invalid data? For LineCharts and AreaCharts we can assume data is invalid/bad/corrupt when to elements have identical x values.

Therefore the main responsibility and final call should be of the library user to provide clean data.

However, with a little change we can make the AreaChart provide the same fallback with or without the usage of Stack.

That is to dedup the data. One objection might be, we don't know the identity function for all given data, i.e. how do we know two elements are equal.

In Victory we already assume the identity of the data:

const x1 = isDate ? datum._x.getTime() : datum._x;

We can dedup the elements and removing duplicate instances from the stack.

Fixes #2883 or rather addresses it.

Type of Change

• 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 not work as expected)
• This change requires a documentation update

How Has This Been Tested?

Manually and adding jest test for testing the dedup logic.

Manually

Before

After

Jest

Created a new suite to mock almost all calls out, expect for the fillData function that has been modified.

Checklist: (Feel free to delete this section upon completion)

• I have included a changeset if this change will require a version change to one of the packages.
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have run all builds, tests, and linting and all checks pass
• I have added tests that prove my fix is effective or that my feature works
• My changes generate no new warnings
• Any dependent changes have been merged and published in downstream modules

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Name	Status	Preview	Comments	Updated (UTC)
victory	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Sep 13, 2024 1:30pm

[changeset-bot]

🦋 Changeset detected

Latest commit: 48fd666

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 31 packages

Name	Type
victory-stack	Patch
victory-native	Patch
victory	Patch
victory-area	Patch
victory-axis	Patch
victory-bar	Patch
victory-box-plot	Patch
victory-brush-container	Patch
victory-brush-line	Patch
victory-candlestick	Patch
victory-canvas	Patch
victory-chart	Patch
victory-core	Patch
victory-create-container	Patch
victory-cursor-container	Patch
victory-errorbar	Patch
victory-group	Patch
victory-histogram	Patch
victory-legend	Patch
victory-line	Patch
victory-pie	Patch
victory-polar-axis	Patch
victory-scatter	Patch
victory-selection-container	Patch
victory-shared-events	Patch
victory-tooltip	Patch
victory-vendor	Patch
victory-voronoi-container	Patch
victory-voronoi	Patch
victory-zoom-container	Patch
victory-docs	Patch

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