test: add two test cases for querystring

+ Cover untested branch in the state machine with the string that its first letter is `+` in the key/value. + `qs.unescapeBuffer` shouldn't decode `+` to space. PR-URL: #11551 Reviewed-By: Anna Henningsen <[email protected]> Reviewed-By: James M Snell <[email protected]> Reviewed-By: Colin Ihrig <[email protected]> Reviewed-By: Yuta Hiroto <[email protected]> Reviewed-By: Joyee Cheung <[email protected]>

Author: watilde

test/parallel/test-querystring.js

@@ -69,6 +69,7 @@ const qsTestCases = [
 ['a&a&a&a&','a=&a=&a=&a=',{a: ['','','','']}],
 ['a=&a=value&a=','a=&a=value&a=',{a: ['','value','']}],
 ['foo+bar=baz+quux','foo%20bar=baz%20quux',{'foo bar': 'baz quux'}],
+['+foo=+bar','%20foo=%20bar',{' foo': ' bar'}],
 [null,'',{}],
 [undefined,'',{}]
 ];
@@ -333,6 +334,7 @@ assert.strictEqual(0xa2, b[18]);
 assert.strictEqual(0xe6,b[19]);
 
 assert.strictEqual(qs.unescapeBuffer('a+b',true).toString(),'a b');
+assert.strictEqual(qs.unescapeBuffer('a+b').toString(),'a+b');
 assert.strictEqual(qs.unescapeBuffer('a%').toString(),'a%');
 assert.strictEqual(qs.unescapeBuffer('a%2').toString(),'a%2');
 assert.strictEqual(qs.unescapeBuffer('a%20').toString(),'a ');