Scheduler dataItem bad copy

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Bug report

Current behavior

props.dataItem accessed from a custom SchedulerItem is a copy of the inserted data item for some reason, and instead of being an instance of a class it is now an object where getters and methods are lost.

Expected behavior

Expect dataItem either to be a reference to an item passed in the data array in the Scheduler component or a correct copy.

Minimal reproduction of the problem with instructions

https://stackblitz.com/edit/react-rbhpac?file=app/main.tsx Look in the console, expected to log:

Inside CustomItem
<image url>
true //instanceof expected class

Instead it logs:

Inside CustomItem
undefined
false //instanceof expected class

What is the motivation or use case for changing the behavior?

I have an instance of a utility class Color in the dataItem for rendering the background color, where I want to access a getter for the hexadecimal value of the color and a method used to calculate contrast to decide the color of the text.

Environment

Package versions:

@progress/kendo-date-math
1.5.2

@progress/kendo-drawing
1.11.0

@progress/kendo-licensing
1.2.0

@progress/kendo-react-animation
4.8.0

@progress/kendo-react-buttons
4.8.0

@progress/kendo-react-dateinputs
4.8.0

@progress/kendo-react-dialogs
4.8.0

@progress/kendo-react-dropdowns
4.8.0

@progress/kendo-react-form
4.8.0

@progress/kendo-react-inputs
4.8.0

@progress/kendo-react-intl
4.8.0
@progress/kendo-react-labels
4.8.0

@progress/kendo-react-popup
4.8.0

@progress/kendo-react-scheduler
4.8.0

@progress/kendo-react-treeview
4.8.0

@types/react
17.0.19

@types/react-dom
17.0.9

prop-types
15.7.2

react
17.0.2

react-dom
17.0.2

Browser:

Firefox version 91.0.2

System:

TypeScript version: 4.4.2
Node version: 16.0.8
Platform: Windows

Obviously I can just make objects out of my instances, but that seems like unnecessary and avoidable code.

telerik / kendo-react