UnitControl: mark unit prop as deprecated

packages/components/src/unit-control/index.tsx

@@ -15,6 +15,7 @@ import classnames from 'classnames';
 /**
  * WordPress dependencies
  */
+import deprecated from '@wordpress/deprecated';
 import { forwardRef, useMemo, useRef, useEffect } from '@wordpress/element';
 import { __ } from '@wordpress/i18n';
 
@@ -57,6 +58,15 @@ function UnforwardedUnitControl(
 	}: WordPressComponentProps< UnitControlProps, 'input', false >,
 	forwardedRef: ForwardedRef< any >
 ) {
+	if ( typeof unitProp !== 'undefined' ) {
+		deprecated( 'UnitControl unit prop', {
+			since: '5.6',
+			hint:
+				'Please provide a unit with a value through the `value` prop.',
+			version: '6.2',
+		} );
+	}
+
 	// The `value` prop, in theory, should not be `null`, but the following line
 	// ensures it fallback to `undefined` in case a consumer of `UnitControl`
 	// still passes `null` as a `value`.

packages/components/src/unit-control/types.ts

@@ -73,7 +73,7 @@ export type UnitSelectControlProps = {
 };
 
 // TODO: when available, should (partially) extend `NumberControl` props.
-export type UnitControlProps = UnitSelectControlProps &
+export type UnitControlProps = Omit< UnitSelectControlProps, 'unit' > &
 	Pick< InputControlProps, 'hideLabelFromVision' > & {
 		__unstableStateReducer?: StateReducer;
 		__unstableInputWidth?: CSSProperties[ 'width' ];
@@ -105,6 +105,12 @@ export type UnitControlProps = UnitSelectControlProps &
 		 * Callback when the `unit` changes.
 		 */
 		onUnitChange?: UnitControlOnChangeCallback;
+		/**
+		 * Current unit. _Note: this prop is deprecated. Instead, provide a unit with a value through the `value` prop._
+		 *
+		 * @deprecated
+		 */
+		unit?: string;
 		/**
 		 * Current value. If passed as a string, the current unit will be inferred from this value.
 		 * For example, a `value` of "50%" will set the current unit to `%`.