Queryparams incorrectly parsing arrays

[racinmat]

Representing an array in query parameter is tricky and there is no single true way, but I think at least one of the often-used approaches should be supported.
Current behavior is:

julia> using URIs
julia> queryparams("foo=bar,qux")
Dict{String,String} with 1 entry:
  "foo" => "bar,qux"

julia> queryparams("foo[]=bar&foo[]=qux")
Dict{String,String} with 1 entry:
  "foo[]" => "qux"

julia> queryparams("foo=bar&foo=qux")
Dict{String,String} with 1 entry:
  "foo" => "qux"

julia> queryparams("foo%5B%5D=bar&foo%5B%5D=qux")
Dict{String,String} with 1 entry:
  "foo[]" => "qux"

I would expect all of them, or at least the ones with repeated foo to return an array instead of string with single value.
It would make the type-stability more complicated, because now it's Dict{String,String}, so accommodating arrays there would mean changing it probably to Dict{String,Union{Vector},String}}?
I'm not sure how the proper solution should look like, but we should not definitely lose parameters as the current behavior does.

[fredrikekre]

There is a WIP PR for this here: JuliaWeb/HTTP.jl#433 (just need to decide the return type in case of multiple identical keys).

[jondea]

This issue has just bit me while using Oxygen.jl. Any progress on this?

If anyone is coming here looking for a hacky solution, I used this workaround

function queryparamdict(req::HTTP.Request)
    d = Dict{String,Any}()
    params = queryparampairs(URI(req.target))
    for (key,value) in params
        if key ∈ keys(d)
            d[key] = [d[key]; value]
        else
            d[key] = value
        end
    end
    return d
end