Deprecate the old querystring in favor of URLSearchParams?

[jimmywarting]

What do you think? should a warning be shown if someone is requiring the querystring?

• URLSearchParams uses a more selective and fine grained approach to selecting encoded characters than that used by the Legacy API.
• URLSearchParams is a spec standard, more ppl should know how it works
• querystring is inconsistent when it comes to adding same keys more then once (by switching between string and arrays)
  • if your server depends on some key being used once ?key=val the you would expect that it would be a string
    But if someone where to add it twice ?key=val&key=val2 then it becomes an array and your application would do unexpected things.
• works in more environments -> means fewer dependencies

[cjihrig]

should a warning be shown if someone is requiring the querystring?

No

[Trott]

I'm OK with encouraging folks to use the newer and better stuff. Do that in the docs by all means. But adding a warning to querystring has very little upside (to the maintainers, at least--whether a warning is a service or disservice to users is an open question) and a massive downside:

• Not much upside: There is no benefit to the project maintainers. It's not like we're ever going to be able to get rid of querystring, at least not in the next five years or any timeline like that. (Look how long domains has been deprecated!)

• Big downside: There will be a massive annoyance to package maintainers. People will see the warning, then open issues in repositories, telling the maintainers to fix their code that is in fact working perfectly well. Not a problem if you maintain one or two packages, but those who maintain tens or hundreds will be very unhappy, understandably. This is what happened when we tried to have a warning appear for all instances of new Buffer(). (We changed it so that it only appears outside of node_modules.)

Yes, people should know about the newer and better stuff. But that's going to have to be the job of documentation and tutorials. As I said before, whether a warning is a service or disservice to users is an open question. But I don't think it would be anywhere near enough to balance the downside.

[jasnell]

I'd be fine with marking it as Legacy status in the docs but deprecating wouldn't be good right now.