Preserve encoded commas when using arrayFormat: 'comma' (#236)

index.js

@@ -106,7 +106,7 @@ function parserForArrayFormat(options) {
 		case 'comma':
 			return (key, value, accumulator) => {
 				const isArray = typeof value === 'string' && value.split('').indexOf(',') > -1;
-				const newValue = isArray ? value.split(',') : value;
+				const newValue = isArray ? value.split(',').map(item => decode(item, options)) : value === null ? value : decode(value, options);
 				accumulator[key] = newValue;
 			};
 
@@ -220,7 +220,7 @@ function parse(input, options) {
 
 		// Missing `=` should be `null`:
 		// http://w3.org/TR/2012/WD-url-20120524/#collect-url-parameters
-		value = value === undefined ? null : decode(value, options);
+		value = value === undefined ? null : options.arrayFormat === 'comma' ? value : decode(value, options);
 		formatter(decode(key, options), value, ret);
 	}
 

test/parse.js

@@ -284,3 +284,12 @@ test('parseNumbers and parseBooleans can work with arrayFormat at the same time'
 	t.deepEqual(queryString.parse('foo=true,false&bar=1,2', {parseNumbers: true, parseBooleans: true, arrayFormat: 'comma'}), {foo: [true, false], bar: [1, 2]});
 	t.deepEqual(queryString.parse('foo[0]=true&foo[1]=false&bar[0]=1&bar[1]=2', {parseNumbers: true, parseBooleans: true, arrayFormat: 'index'}), {foo: [true, false], bar: [1, 2]});
 });
+
+test('query strings having comma encoded and format option as `comma`', t => {
+	t.deepEqual(queryString.parse('foo=zero%2Cone,two%2Cthree', {arrayFormat: 'comma'}), {
+		foo: [
+			'zero,one',
+			'two,three'
+		]
+	});
+});