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

Author: Joris-van-der-Wel

lib/SymbolTree.js

@@ -324,21 +324,18 @@ class SymbolTree {
          * @method treeToArray
          * @memberOf module:symbol-tree#
          * @param {Object} root
-         * @param {Object[]} [array=[]]
-         * @param {Function} [filter] Function to test each object before it is added to the array.
+         * @param {Object} [options]
+         * @param {Object[]} [options.array=[]]
+         * @param {Function} [options.filter] Function to test each object before it is added to the array.
          *                            Invoked with arguments (object). Should return `true` if an object
          *                            is to be included.
-         * @param {*} [thisArg] Value to use as `this` when executing `filter`.
+         * @param {*} [options.thisArg] Value to use as `this` when executing `filter`.
          * @return {Object[]}
          */
-        treeToArray(root, array, filter, thisArg) {
-                if (!array) {
-                        array = [];
-                }
-
-                if (!filter) {
-                        filter = returnTrue;
-                }
+        treeToArray(root, options) {
+                const array   = (options && options.array  ) || [];
+                const filter  = (options && options.filter ) || returnTrue;
+                const thisArg = (options && options.thisArg) || undefined;
 
                 let object = root;
 

test/SymbolTree.js

@@ -907,7 +907,7 @@ test('treeToArray', function(t) {
         t.deepEqual([a, aa, ab, aba, abaa], tree.treeToArray(a));
 
         const arr = ['a', 5];
-        tree.treeToArray(a, arr);
+        tree.treeToArray(a, {array: arr});
         t.deepEqual(['a', 5, a, aa, ab, aba, abaa], arr);
 
         t.end();
@@ -934,7 +934,7 @@ test('treeToArray with filter', function(t) {
                 return object !== a && object !== aba;
         };
 
-        t.deepEqual([aa, ab, abaa], tree.treeToArray(a, null, filter));
+        t.deepEqual([aa, ab, abaa], tree.treeToArray(a, {filter: filter}));
 
         const thisArg = {foo: 'bar'};
         const filterThis = function(object) {
@@ -943,7 +943,7 @@ test('treeToArray with filter', function(t) {
                 return object !== a && object !== aba;
         };
 
-        t.deepEqual([aa, ab, abaa], tree.treeToArray(a, null, filterThis, thisArg));
+        t.deepEqual([aa, ab, abaa], tree.treeToArray(a, {filter: filterThis, thisArg: thisArg}));
 
         t.end();
 });