setImmutably: don't clone all objects

packages/block-editor/src/utils/object.js

@@ -55,33 +55,6 @@ export function kebabCase( str ) {
 	} );
 }
 
-/**
- * Clones an object.
- * Arrays are also cloned as arrays.
- * Non-object values are returned unchanged.
- *
- * @param {*} object Object to clone.
- * @return {*} Cloned object, or original literal non-object value.
- */
-function cloneObject( object ) {
-	if ( Array.isArray( object ) ) {
-		return object.map( cloneObject );
-	}
-
-	if ( object && typeof object === 'object' ) {
-		return {
-			...Object.fromEntries(
-				Object.entries( object ).map( ( [ key, value ] ) => [
-					key,
-					cloneObject( value ),
-				] )
-			),
-		};
-	}
-
-	return object;
-}
-
 /**
  * Immutably sets a value inside an object. Like `lodash#set`, but returning a
  * new object. Treats nullish initial values as empty objects. Clones any
@@ -93,24 +66,20 @@ function cloneObject( object ) {
  * @return {Object} Cloned object with the new value set.
  */
 export function setImmutably( object, path, value ) {
-	const normalizedPath = normalizePath( path );
-	const newObject = object ? cloneObject( object ) : {};
+	path = normalizePath( path );
+
+	if ( path.length === 0 ) {
+		throw new Error( 'Path cannot be empty' );
+	}
+
+	const clonedObj = Array.isArray( object ) ? [ ...object ] : { ...object };
+	const [ first, ...rest ] = path;
 
-	normalizedPath.reduce( ( acc, key, i ) => {
-		if ( acc[ key ] === undefined ) {
-			if ( Number.isInteger( path[ i + 1 ] ) ) {
-				acc[ key ] = [];
-			} else {
-				acc[ key ] = {};
-			}
-		}
-		if ( i === normalizedPath.length - 1 ) {
-			acc[ key ] = value;
-		}
-		return acc[ key ];
-	}, newObject );
+	clonedObj[ first ] = rest.length
+		? setImmutably( clonedObj[ first ], rest, value )
+		: value;
 
-	return newObject;
+	return clonedObj;
 }
 
 const stringToPath = memoize( ( path ) => path.split( '.' ) );