[Fix] stringify: encode comma values more consistently

Author: bakkerthehacker

.eslintrc

@@ -15,7 +15,7 @@
         "indent": [2, 4],
         "max-lines-per-function": [2, { "max": 150 }],
         "max-params": [2, 16],
-        "max-statements": [2, 53],
+        "max-statements": [2, 100],
         "multiline-comment-style": 0,
         "no-continue": 1,
         "no-magic-numbers": 0,

lib/stringify.js

@@ -19,7 +19,6 @@ var arrayPrefixGenerators = {
 };
 
 var isArray = Array.isArray;
-var split = String.prototype.split;
 var push = Array.prototype.push;
 var pushToArray = function (arr, valueOrArray) {
     push.apply(arr, isArray(valueOrArray) ? valueOrArray : [valueOrArray]);
@@ -121,14 +120,6 @@ var stringify = function stringify(
     if (isNonNullishPrimitive(obj) || utils.isBuffer(obj)) {
         if (encoder) {
             var keyValue = encodeValuesOnly ? prefix : encoder(prefix, defaults.encoder, charset, 'key', format);
-            if (generateArrayPrefix === 'comma' && encodeValuesOnly) {
-                var valuesArray = split.call(String(obj), ',');
-                var valuesJoined = '';
-                for (var i = 0; i < valuesArray.length; ++i) {
-                    valuesJoined += (i === 0 ? '' : ',') + formatter(encoder(valuesArray[i], defaults.encoder, charset, 'value', format));
-                }
-                return [formatter(keyValue) + (commaRoundTrip && isArray(obj) && valuesArray.length === 1 ? '[]' : '') + '=' + valuesJoined];
-            }
             return [formatter(keyValue) + '=' + formatter(encoder(obj, defaults.encoder, charset, 'value', format))];
         }
         return [formatter(prefix) + '=' + formatter(String(obj))];
@@ -143,6 +134,9 @@ var stringify = function stringify(
     var objKeys;
     if (generateArrayPrefix === 'comma' && isArray(obj)) {
         // we need to join elements in
+        if (encodeValuesOnly && encoder) {
+            obj = utils.maybeMap(obj, encoder);
+        }
         objKeys = [{ value: obj.length > 0 ? obj.join(',') || null : void undefined }];
     } else if (isArray(filter)) {
         objKeys = filter;
@@ -175,7 +169,7 @@ var stringify = function stringify(
             commaRoundTrip,
             strictNullHandling,
             skipNulls,
-            encoder,
+            generateArrayPrefix === 'comma' && encodeValuesOnly && isArray(obj) ? null : encoder,
             filter,
             sort,
             allowDots,

test/stringify.js

@@ -162,7 +162,7 @@ test('stringify()', function (t) {
 
         st.test('array with multiple items with a comma inside', function (s2t) {
             s2t.equal(qs.stringify({ a: ['c,d', 'e'] }, { encodeValuesOnly: true, arrayFormat: 'comma' }), 'a=c%2Cd,e');
-            s2t.equal(qs.stringify({ a: ['c,d', 'e'] }, { arrayFormat: 'comma' }), 'a=c%25%2Cd%2Ce');
+            s2t.equal(qs.stringify({ a: ['c,d', 'e'] }, { arrayFormat: 'comma' }), 'a=c%2Cd%2Ce');
 
             s2t.end();
         });
@@ -178,6 +178,44 @@ test('stringify()', function (t) {
         st.end();
     });
 
+    t.test('stringifies comma and empty array values', function (st) {
+        st.equal(qs.stringify({ a: [',', '', 'c,d%'] }, { encode: false, arrayFormat: 'indices' }), 'a[0]=,&a[1]=&a[2]=c,d%');
+        st.equal(qs.stringify({ a: [',', '', 'c,d%'] }, { encode: false, arrayFormat: 'brackets' }), 'a[]=,&a[]=&a[]=c,d%');
+        st.equal(qs.stringify({ a: [',', '', 'c,d%'] }, { encode: false, arrayFormat: 'comma' }), 'a=,,,c,d%');
+        st.equal(qs.stringify({ a: [',', '', 'c,d%'] }, { encode: false, arrayFormat: 'repeat' }), 'a=,&a=&a=c,d%');
+
+        st.equal(qs.stringify({ a: [',', '', 'c,d%'] }, { encode: true, encodeValuesOnly: true, arrayFormat: 'indices' }), 'a[0]=%2C&a[1]=&a[2]=c%2Cd%25');
+        st.equal(qs.stringify({ a: [',', '', 'c,d%'] }, { encode: true, encodeValuesOnly: true, arrayFormat: 'brackets' }), 'a[]=%2C&a[]=&a[]=c%2Cd%25');
+        st.equal(qs.stringify({ a: [',', '', 'c,d%'] }, { encode: true, encodeValuesOnly: true, arrayFormat: 'comma' }), 'a=%2C,,c%2Cd%25');
+        st.equal(qs.stringify({ a: [',', '', 'c,d%'] }, { encode: true, encodeValuesOnly: true, arrayFormat: 'repeat' }), 'a=%2C&a=&a=c%2Cd%25');
+
+        st.equal(qs.stringify({ a: [',', '', 'c,d%'] }, { encode: true, encodeValuesOnly: false, arrayFormat: 'indices' }), 'a%5B0%5D=%2C&a%5B1%5D=&a%5B2%5D=c%2Cd%25');
+        st.equal(qs.stringify({ a: [',', '', 'c,d%'] }, { encode: true, encodeValuesOnly: false, arrayFormat: 'brackets' }), 'a%5B%5D=%2C&a%5B%5D=&a%5B%5D=c%2Cd%25');
+        st.equal(qs.stringify({ a: [',', '', 'c,d%'] }, { encode: true, encodeValuesOnly: false, arrayFormat: 'comma' }), 'a=%2C%2C%2Cc%2Cd%25');
+        st.equal(qs.stringify({ a: [',', '', 'c,d%'] }, { encode: true, encodeValuesOnly: false, arrayFormat: 'repeat' }), 'a=%2C&a=&a=c%2Cd%25');
+
+        st.end();
+    });
+
+    t.test('stringifies comma and empty non-array values', function (st) {
+        st.equal(qs.stringify({ a: ',', b: '', c: 'c,d%' }, { encode: false, arrayFormat: 'indices' }), 'a=,&b=&c=c,d%');
+        st.equal(qs.stringify({ a: ',', b: '', c: 'c,d%' }, { encode: false, arrayFormat: 'brackets' }), 'a=,&b=&c=c,d%');
+        st.equal(qs.stringify({ a: ',', b: '', c: 'c,d%' }, { encode: false, arrayFormat: 'comma' }), 'a=,&b=&c=c,d%');
+        st.equal(qs.stringify({ a: ',', b: '', c: 'c,d%' }, { encode: false, arrayFormat: 'repeat' }), 'a=,&b=&c=c,d%');
+
+        st.equal(qs.stringify({ a: ',', b: '', c: 'c,d%' }, { encode: true, encodeValuesOnly: true, arrayFormat: 'indices' }), 'a=%2C&b=&c=c%2Cd%25');
+        st.equal(qs.stringify({ a: ',', b: '', c: 'c,d%' }, { encode: true, encodeValuesOnly: true, arrayFormat: 'brackets' }), 'a=%2C&b=&c=c%2Cd%25');
+        st.equal(qs.stringify({ a: ',', b: '', c: 'c,d%' }, { encode: true, encodeValuesOnly: true, arrayFormat: 'comma' }), 'a=%2C&b=&c=c%2Cd%25');
+        st.equal(qs.stringify({ a: ',', b: '', c: 'c,d%' }, { encode: true, encodeValuesOnly: true, arrayFormat: 'repeat' }), 'a=%2C&b=&c=c%2Cd%25');
+
+        st.equal(qs.stringify({ a: ',', b: '', c: 'c,d%' }, { encode: true, encodeValuesOnly: false, arrayFormat: 'indices' }), 'a=%2C&b=&c=c%2Cd%25');
+        st.equal(qs.stringify({ a: ',', b: '', c: 'c,d%' }, { encode: true, encodeValuesOnly: false, arrayFormat: 'brackets' }), 'a=%2C&b=&c=c%2Cd%25');
+        st.equal(qs.stringify({ a: ',', b: '', c: 'c,d%' }, { encode: true, encodeValuesOnly: false, arrayFormat: 'comma' }), 'a=%2C&b=&c=c%2Cd%25');
+        st.equal(qs.stringify({ a: ',', b: '', c: 'c,d%' }, { encode: true, encodeValuesOnly: false, arrayFormat: 'repeat' }), 'a=%2C&b=&c=c%2Cd%25');
+
+        st.end();
+    });
+
     t.test('stringifies a nested array value with dots notation', function (st) {
         st.equal(
             qs.stringify(