fix: support symbol as object key

Author: twada

Diff for: index.js

@@ -53,7 +53,7 @@ function createStringifier (customOptions) {
   return function stringifyAny (push, x) {
     const context = this;
     let handler = handlerFor(context.node, options, handlers);
-    const currentPath = '/' + context.path.join('/');
+    const currentPath = '/' + context.path.map(String).join('/');
     const customization = handlers[currentPath];
     const acc = {
       context: context,

Diff for: strategies.js

@@ -244,7 +244,11 @@ function decorateObject () {
 }
 
 function sanitizeKey (key) {
-  return /^[A-Za-z_]+$/.test(key) ? key : JSON.stringify(key);
+  if (typeof key === 'symbol') {
+    return key.toString();
+  } else {
+    return /^[A-Za-z_]+$/.test(key) ? key : JSON.stringify(key);
+  }
 }
 
 function afterAllChildren (context, push, options) {