Calcite Combobox "single-persist" selection mode does not prevent deselection

[GealSarrett]

Check existing issues

• I have checked for existing issues to avoid duplicates

Actual Behavior

Setting the selection mode to "single-persist" behaves identically to "single" mode. The user is allowed to use the "x" chip to remove their selection.

Expected Behavior

The user, per the documentation on the single-persist selection mode, should not be able to clear the selected item.

Reproduction Sample

https://developers.arcgis.com/calcite-design-system/components/combobox/

Reproduction Steps

1. Open the sample page
2. Change the selection mode to "single-persist"
3. Select an item in the combobox
4. Click on the gray "x" chip button in the combo-box

Reproduction Version

2.11.1

Relevant Info

Windows 11, Edge, Firefox and Chrome. No console errors/warnings.

Regression?

Not sure.

Priority impact

impact - p3 - not time sensitive

Impact

Requires adding additional scripting logic alongside the component to account for the possibility of user deselection.

Calcite package

• @esri/calcite-components
• @esri/calcite-components-angular
• @esri/calcite-components-react
• @esri/calcite-design-tokens
• @esri/eslint-plugin-calcite-components

Esri team

N/A

[macandcheese]

As a workaround you can use clear-disabled property in combination with selection-mode="single-persist".

cc @DitwanP re: potential documentation update for the selection-mode prop?

[geospatialem]

Spike to determine functionality of selection-mode="single-persist" and next steps. For the spike effort refer to some discussion in #4738 for additional background/history.