[Refactor] stringify: Avoid arr = arr.concat(...), push to the exis…

…ting instance (#269)
ljharb · Jul 26, 2018 · bc90696 · bc90696
1 parent 47e46a6
commit bc90696
Showing 1 changed file with 9 additions and 4 deletions.
diff --git a/lib/stringify.js b/lib/stringify.js
@@ -15,6 +15,12 @@ var arrayPrefixGenerators = {
     }
 };
 
+var isArray = Array.isArray;
+var push = Array.prototype.push;
+var pushToArray = function (arr, valueOrArray) {
+    push.apply(arr, isArray(valueOrArray) ? valueOrArray : [valueOrArray]);
+};
+
 var toISO = Date.prototype.toISOString;
 
 var defaults = {
@@ -85,7 +91,7 @@ var stringify = function stringify( // eslint-disable-line func-name-matching
         }
 
         if (Array.isArray(obj)) {
-            values = values.concat(stringify(
+            pushToArray(values, stringify(
                 obj[key],
                 generateArrayPrefix(prefix, key),
                 generateArrayPrefix,
@@ -99,7 +105,7 @@ var stringify = function stringify( // eslint-disable-line func-name-matching
                 formatter
             ));
         } else {
-            values = values.concat(stringify(
+            pushToArray(values, stringify(
                 obj[key],
                 prefix + (allowDots ? '.' + key : '[' + key + ']'),
                 generateArrayPrefix,
@@ -182,8 +188,7 @@ module.exports = function (object, opts) {
         if (skipNulls && obj[key] === null) {
             continue;
         }
-
-        keys = keys.concat(stringify(
+        pushToArray(keys, stringify(
             obj[key],
             key,
             generateArrayPrefix,