querystring.stringify appends =& to params without value

[thisconnect]

• Version: v6.9.1
• Platform: Darwin 16.0.0 Darwin Kernel Version 16.0.0: Mon Aug 29 17:56:20 PDT 2016; root:xnu-3789.1.32~3/RELEASE_X86_64 x86_64

Assuming this should return 'foo&bar&baz':

const qs = require('querystring')

console.log(qs.stringify(qs.parse('foo&bar&baz')))

acutal output is foo=&bar=&baz=

qs.parse('foo&bar&baz') returns { foo: '', bar: '', baz: '' },
qs.stringify({ foo: '', bar: '', baz: '' }) returns foo=&bar=&baz=

Would you consider this behavior a bug?

related docs https://nodejs.org/api/querystring.html#querystring_querystring_stringify_obj_sep_eq_options

this seems to be the reason that an equal sign is appended to valueless qs params. See following example:

const url = require('url')
const qs = require('querystring')


const href = 'http://example.com/?foo&bar#baz'
const { protocol, host, pathname, query, hash } = url.parse(href)
console.log(url.format({ protocol, host, pathname, query: qs.parse(query), hash }))

// expected http://example.com/?foo&bar#baz
// returned http://example.com/?foo=&bar=#baz

expect to log http://example.com/?foo&bar#baz
actual output http://example.com/?foo=&bar=#baz

Side note qs.stringify doesn't care if the value is '' or null or undefined
console.log(qs.stringify({ foo: '', bar: null, baz: undefined })) returns foo=&bar=&baz=

Personally it would be really helpful if querystring.parse would return null instead of '' and if querystring.stringify would omit the = sign (eq option) when a parameter is null

[cjihrig]

This has been brought up multiple times in the past (including by me). If you need this behavior, I think your best bet is to use an alternative from userland.

[thisconnect]

@cjihrig it is fixed it in my code. Nevertheless...

Could you point me to the issue that you are referring to?

I can only find:

• [Node API] querystring: 'Flag' instead argument+value #7330
• querystring.stringify behavior for undefined, null, empty array[], should be improved node-v0.x-archive#7971

So do you consider the current behavior a bug that needs to be fixed. OR the desired behavior that should be documented?

[cjihrig]

@thisconnect there is also nodejs/node-v0.x-archive#8829 and nodejs/node-v0.x-archive#8825.

I don't necessarily think that the behavior is a bug, but it is confusing IMO. I think it might be too late to do anything about it though, as it would likely break code.

[TimothyGu]

The current behavior is actually the standardized one. For example, URLSearchParams in both Node.js and the browser acts the same way:

> new URLSearchParams('foo&bar&baz').toString()
< "foo=&bar=&baz="

Plus as @cjihrig pointed out it's too late to change anyway. Thus closing.