Strange behavior when one of query params empty

[tahonaPL]

Values of all query params are "undefined" when first value is empty.

version : 20.23.00

Given on request /../?test1=&test2=someValue

When
const test2 = req.getQuery("test2")

Then if (test2 != "someValue") throw new Error("Something off")

[uNetworkingAB]

https://github.com/uNetworking/uWebSockets/blob/master/src/QueryParser.h

Probably an edge case not implemented properly.

[e3dio]

Here is fast performing query parser in JS that works for all cases (for % encoded see below):

const parseQuery = s => {
   const m = new Map();
   if (!s.length) return m;
   let i = 0, i2, i3;
   do {
      i2 = s.indexOf('=', i);
      if (i2 == -1) i2 = s.length;
      i3 = s.indexOf('&', i2 + 1);
      if (i3 == -1) i3 = s.length;
      m.set(s.slice(i, i2), s.slice(i2 + 1, i3));
      i = i3 + 1;
   } while (i3 != s.length)
   return m;
};

const query = parseQuery(req.getQuery());
const val = query.get('param1');

[uNetworkingAB]

Don't you need to escape % hex also

[e3dio]

If you have % escaped in your query keys you need to update the parser function which will slow it down, or if you have % escaped in query values for specific keys you can check after parse with const decode = str => str.includes('%') ? decodeURIComponent(str) : str for better performance. So it's not fit-all solution which you would need for official library, but ideally you don't have % in your query keys, and you can specify which keys you want to check for % values after parsing

[0x7d8]

Here is fast performing query parser in JS that works for all cases (for % encoded see below):

const parseQuery = s => {
   const m = new Map();
   if (!s.length) return m;
   let i = 0, i2, i3;
   do {
      i2 = s.indexOf('=', i);
      if (i2 == -1) i2 = s.length;
      i3 = s.indexOf('&', i2 + 1);
      if (i3 == -1) i3 = s.length;
      m.set(s.slice(i, i2), s.slice(i2 + 1, i3));
      i = i3 + 1;
   } while (i3 != s.length)
   return m;
};

const query = parseQuery(req.getQuery());
const val = query.get('param1');

is it intended that "q1&q2" for example ends up as "q1&q2" -> "" instead of "q1" -> "" & "q2" -> ""?

[e3dio]

To me that is correct, if you want { q1: '', q2: '' } the query string needs to be q1=&q2=. You need to send valid query strings

[0x7d8]

Yeah, I just find it interesting because the built in querystring.parse also does "q1" -> "" & "q2" -> ""

[uNetworkingAB]

https://github.com/uNetworking/uWebSockets/commit/a658d1616abea0c107108d3bc60c36201bd5f807

Should be fixed in that commit, will let it run fuzzing before new release

[uNetworkingAB]

@tahonaPL Did you really get "undefined", didn't you get empty string? It should not be possible to get "undefined", ever. But we need to distinguish empty string from undefined, now

[uNetworkingAB]

https://github.com/uNetworking/uWebSockets/releases/tag/v20.40.0

[uNetworkingAB]

Fixed in latest release