Use an options argument instead of various arguments, for treeIterator()

Author: Joris-van-der-Wel

lib/SymbolTree.js

@@ -439,10 +439,13 @@ class SymbolTree {
          * @method treeIterator
          * @memberOf module:symbol-tree#
          * @param {Object} root
-         * @param {Boolean} [reverse=false]
+         * @param {Object} options
+         * @param {Boolean} [options.reverse=false]
          * @return {Object} An iterable iterator (ES6)
          */
-        treeIterator(root, reverse) {
+        treeIterator(root, options) {
+                const reverse = options && options.reverse;
+
                 return new TreeIterator(
                         this,
                         root,

test/SymbolTree.js

@@ -996,7 +996,7 @@ test('tree iterator reverse', function(t) {
         tree.insertAfter(b, a);
 
         const results = [];
-        const iterator = tree.treeIterator(a, true);
+        const iterator = tree.treeIterator(a, {reverse: true});
 
         for (const object of iterator) {
                 results.push(object);