[New] support enumerable Symbol properties

index.js

@@ -30,6 +30,25 @@ var objectKeys = Object.keys || function keys(obj) {
 	return res;
 };
 
+var propertyIsEnumerable = Object.prototype.propertyIsEnumerable;
+var getOwnPropertySymbols = Object.getOwnPropertySymbols; // eslint-disable-line id-length
+
+// TODO: use reflect.ownkeys and filter out non-enumerables
+function ownEnumerableKeys(obj) {
+	var res = objectKeys(obj);
+
+	// Include enumerable symbol properties.
+	if (getOwnPropertySymbols) {
+		var symbols = getOwnPropertySymbols(obj);
+		for (var i = 0; i < symbols.length; i++) {
+			if (propertyIsEnumerable.call(obj, symbols[i])) {
+				res.push(symbols[i]);
+			}
+		}
+	}
+	return res;
+}
+
 // TODO: use object.hasown
 var hasOwnProperty = Object.prototype.hasOwnProperty || function (obj, key) {
 	return key in obj;
@@ -62,7 +81,7 @@ function copy(src) {
 			dst = new T();
 		}
 
-		forEach(objectKeys(src), function (key) {
+		forEach(ownEnumerableKeys(src), function (key) {
 			dst[key] = src[key];
 		});
 		return dst;
@@ -124,7 +143,7 @@ function walk(root, cb, immutable) {
 		function updateState() {
 			if (typeof state.node === 'object' && state.node !== null) {
 				if (!state.keys || state.node_ !== state.node) {
-					state.keys = objectKeys(state.node);
+					state.keys = ownEnumerableKeys(state.node);
 				}
 
 				state.isLeaf = state.keys.length === 0;
@@ -281,7 +300,7 @@ Traverse.prototype.clone = function () {
 			parents.push(src);
 			nodes.push(dst);
 
-			forEach(objectKeys(src), function (key) {
+			forEach(ownEnumerableKeys(src), function (key) {
 				dst[key] = clone(src[key]);
 			});
 
@@ -300,7 +319,7 @@ function traverse(obj) {
 }
 
 // TODO: replace with object.assign?
-forEach(objectKeys(Traverse.prototype), function (key) {
+forEach(ownEnumerableKeys(Traverse.prototype), function (key) {
 	traverse[key] = function (obj) {
 		var args = [].slice.call(arguments, 1);
 		var t = new Traverse(obj);

package.json

@@ -11,6 +11,7 @@
 		"@ljharb/eslint-config": "^21.1.0",
 		"aud": "^2.0.4",
 		"auto-changelog": "^2.4.0",
+		"es-value-fixtures": "^1.4.2",
 		"eslint": "=8.8.0",
 		"in-publish": "^2.0.1",
 		"npmignore": "^0.3.1",

test/has.js

@@ -1,6 +1,7 @@
 'use strict';
 
 var test = require('tape');
+var v = require('es-value-fixtures');
 var traverse = require('../');
 
 test('has', function (t) {
@@ -13,5 +14,26 @@ test('has', function (t) {
 	t.equal(traverse(obj).has(['a']), true);
 	t.equal(traverse(obj).has(['a', 2]), false);
 
+	t.test('symbols', { skip: !v.hasSymbols }, function (st) {
+		/* eslint no-restricted-properties: 1 */
+		var globalSymbol = Symbol.for('d');
+		var localSymbol = Symbol('e');
+
+		obj[globalSymbol] = {};
+		obj[globalSymbol][localSymbol] = 7;
+		obj[localSymbol] = 8;
+
+		st.equal(traverse(obj).has([globalSymbol]), true);
+		st.equal(traverse(obj).has([globalSymbol, globalSymbol]), false);
+		st.equal(traverse(obj).has([globalSymbol, localSymbol]), true);
+		st.equal(traverse(obj).has([localSymbol]), true);
+		st.equal(traverse(obj).has([localSymbol]), true);
+		st.equal(traverse(obj).has([Symbol('e')]), false);
+		st.equal(traverse(obj).has([Symbol.for('d')]), true);
+		st.equal(traverse(obj).has([Symbol.for('e')]), false);
+
+		st.end();
+	});
+
 	t.end();
 });