[Fix] do not mutate options argument.

Fixes #207.
ljharb · Apr 11, 2017 · 0d93016 · 0d93016
1 parent 5ebf8b4
commit 0d93016
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Showing 4 changed files with 15 additions and 2 deletions.
diff --git a/lib/parse.js b/lib/parse.js
@@ -130,7 +130,7 @@ var parseKeys = function parseQueryStringKeys(givenKey, val, options) {
 };
 
 module.exports = function (str, opts) {
-    var options = opts || {};
+    var options = opts ? utils.assign({}, opts) : {};
 
     if (options.decoder !== null && options.decoder !== undefined && typeof options.decoder !== 'function') {
         throw new TypeError('Decoder has to be a function.');

diff --git a/lib/stringify.js b/lib/stringify.js
@@ -123,7 +123,7 @@ var stringify = function stringify( // eslint-disable-line func-name-matching
 
 module.exports = function (object, opts) {
     var obj = object;
-    var options = opts || {};
+    var options = opts ? utils.assign({}, opts) : {};
 
     if (options.encoder !== null && options.encoder !== undefined && typeof options.encoder !== 'function') {
         throw new TypeError('Encoder has to be a function.');

diff --git a/test/parse.js b/test/parse.js
@@ -516,4 +516,11 @@ test('parse()', function (t) {
         }, new TypeError('Decoder has to be a function.'));
         st.end();
     });
+
+    t.test('does not mutate the options argument', function (st) {
+        var options = {};
+        qs.parse('a[b]=true', options);
+        st.deepEqual(options, {});
+        st.end();
+    });
 });
diff --git a/test/stringify.js b/test/stringify.js
@@ -564,4 +564,10 @@ test('stringify()', function (t) {
         st.end();
     });
 
+    t.test('does not mutate the options argument', function (st) {
+        var options = {};
+        qs.stringify({}, options);
+        st.deepEqual(options, {});
+        st.end();
+    });
 });