Change multiple values to use array format

[eduardoboucas]

When the object to be encoded contains an array, the resulting string simply repeats the key for each of the values.

Example:

{foo: ['bar', 'baz', 'qux']}

Results in:

foo=bar&foo=baz&foo=qux

However, this only gives access to one of the values (typically the last one). I came across this issue when trying to use oauth to generate a OAuth URL for the GitHub API.
The solution was to use the array convention to represent multiple values for the same key.

Example:

foo[]=bar&foo[]=baz&foo[]=qux

I don't know if you want to adopt this convention (as it can potentially break existing implementations), but in any case I've included the change in the PR.

EDIT (25 July): It doesn't make sense to just change the convention for everyone that's already using the package, so I've added an optional parameter to encode() that activates the array convention. It defaults to false, so everything should work exactly as is if the parameter isn't activated.

To activate it, arrayMode must be set to true. Because of the existing optional parameters in the function, it's necessary to actively set them to undefined in the function call — unfortunate, but in my opinion still better than not having this option at all.

Example:

querystring.encode({foo: ['bar', 'baz', 'qux']}, undefined, undefined, undefined, true);

[emilbayes]

Hey @eduardoboucas, this is pretty common, maybe you should make the same suggestion to nodejs/node? I don't see it suggested over there before. It might be out of scope for the built-in query string implementation though

[johannesnagl]

is this PR going to happen? We need exactly the same behavior and I was wondering why this is not part of the library :/

[sontek]

This project hasn't accepted changes in 4 years, so probably dead? Maybe someone can fork it and get this in?

[sontek]

https://www.npmjs.com/package/qs seems to support it

[RusAlex]

Interesting. I also met the issue. Will try to use qs

[medikoo]

If you're interested to bring this module back to living, here's the proposed roadmap: #20 PR's are very welcome (and I will handle them promptly, I promise :)

I'm going to close this issue, as if request is on pair with Node.js implementation then it'll be there. If it's not, then we're not interesting in deriving from API as it's in Node.js