no extra depth, and cover empty keys

Author: ycw

src/renderers/common/ChainMap.js

@@ -30,9 +30,11 @@ export default class ChainMap {
 	 */
 	get( keys ) {
 
+		if ( keys.length === 0 ) return undefined;
+
 		let map = this.weakMap;
 
-		for ( let i = 0; i < keys.length; i ++ ) {
+		for ( let i = 0; i < keys.length - 1; i ++ ) {
 
 			map = map.get( keys[ i ] );
 
@@ -53,9 +55,11 @@ export default class ChainMap {
 	 */
 	set( keys, value ) {
 
+		if ( keys.length === 0 ) return this;
+
 		let map = this.weakMap;
 
-		for ( let i = 0; i < keys.length; i ++ ) {
+		for ( let i = 0; i < keys.length - 1; i ++ ) {
 
 			const key = keys[ i ];
 
@@ -79,9 +83,11 @@ export default class ChainMap {
 	 */
 	delete( keys ) {
 
+		if ( keys.length === 0 ) return false;
+
 		let map = this.weakMap;
 
-		for ( let i = 0; i < keys.length; i ++ ) {
+		for ( let i = 0; i < keys.length - 1; i ++ ) {
 
 			map = map.get( keys[ i ] );