'querystring.parse' works a inconsistent way with URLSearchParams(chrome) and python's urlparse.parse_qs

[AbnerZheng]

• Version: 7.3.0
• Platform:Mac
• Subsystem: 10.12.1

when parse a paramsString like "&&q=test&topic=api", where '&&' appear together, Node will get the result like this:

querystring.parse("&&q=test&topic=api") //=>{ '': [ '', '' ], q: 'test', topic: 'api' }

But in other environment, such as Chrome console, we will get the result below:

var paramsString = "&&q=test&topic=api"
var searchParams = new URLSearchParams(paramsString);
for(let p of searchParams){ console.log(p);} //=>["q", "test"],["topic", "api"]

The same as python.

[mscdex]

The querystring module is not intended to be 100% compatible with what browsers are doing.

If you're actually parsing a url, have you tried using the experimental WHATWG URL object in recent versions of node (require('url').URL)?

It doesn't seem that the WHATWG implementation is exporting its URLSearchParams, so currently it's only used when parsing a valid url. Perhaps that might be worth exporting though. /cc @jasnell

[TimothyGu]

Currently even URLSearchParams is backed by querystring.parse. Tracking issue is at #10821.

/cc @nodejs/url

[watilde]

Like @TimothyGu said, we need to update the querystring.parse to fix them because of:

node/lib/internal/url.js

Lines 614 to 618 in 6b6123c

	// Reused by the URL parse function invoked by
	// the href setter, and the URLSearchParams constructor
	function initSearchParams(url, init) {
	url[searchParams] = getParamsFromObject(querystring.parse(init));
	}

I opened a PR for it on #10967 😃

[TimothyGu]

Unfortunately, some cases still do not work as expected even after @watilde's fix:

> querystring.parse('a&&b')
{ a: '', '': '', b: '' }
> querystring.parse('a=a&&b=b')
{ a: 'a', '': '', b: 'b' }