Close WebSockets with a status code

[christopher-dG]

@samoconnor's advice on JuliaLang/MbedTLS.jl#186 (comment) worked perfectly 🙂. I also added a check for the connection still being open, since writing to a closed one throws an error.
Closes #347

[christopher-dG]

I'm actually seeing some issues now where when I close with a status code, the next read throws an error with the same code. Investigating!

julia> HTTP.WebSockets.open("wss://echo.websocket.org") do io
       close(io; statuscode=1001)
       end
ERROR: HTTP.WebSockets.WebSocketError(1001, "")
Stacktrace:
 [1] readframe(::HTTP.WebSockets.WebSocket{HTTP.ConnectionPool.Transaction{MbedTLS.SSLContext}}) at /home/degraafc/.julia/packages/HTTP/fJZFG/src/WebSockets.jl:268
 [2] #close#10(::Int64, ::Function, ::HTTP.WebSockets.WebSocket{HTTP.ConnectionPool.Transaction{MbedTLS.SSLContext}}) at /home/degraafc/.julia/packages/HTTP/fJZFG/src/WebSockets.jl:224
 [3] #close at ./none:0 [inlined]
 [4] #3 at ./REPL[15]:2 [inlined]
 [5] (::getfield(HTTP.WebSockets, Symbol("##3#4")){Bool,getfield(Main, Symbol("##3#4")),String})(::HTTP.Streams.Stream{HTTP.Messages.Response,HTTP.ConnectionPool.Transaction{MbedTLS.SSLContext}}) at /home/degraafc/.julia/packages/HTTP/fJZFG/src/WebSockets.jl:109
 [6] macro expansion at ./task.jl:266 [inlined]
 [7] #request#1(::Nothing, ::getfield(HTTP.WebSockets, Symbol("##3#4")){Bool,getfield(Main, Symbol("##3#4")),String}, ::Int64, ::Base.Iterators.Pairs{Union{},Union{},Tuple{},NamedTuple{(),Tuple{}}}, ::Function, ::Type{HTTP.StreamRequest.StreamLayer}, ::HTTP.ConnectionPool.Transaction{MbedTLS.SSLContext}, ::HTTP.Messages.Request, ::Nothing) at /home/degraafc/.julia/packages/HTTP/fJZFG/src/StreamRequest.jl:54
 [8] (::getfield(HTTP, Symbol("#kw##request")))(::NamedTuple{(:iofunction, :verbose),Tuple{getfield(HTTP.WebSockets, Symbol("##3#4")){Bool,getfield(Main, Symbol("##3#4")),String},Int64}}, ::typeof(HTTP.request), ::Type{HTTP.StreamRequest.StreamLayer}, ::HTTP.ConnectionPool.Transaction{MbedTLS.SSLContext}, ::HTTP.Messages.Request, ::Nothing) at ./none:0
 [9] #request#1(::Nothing, ::Type, ::Int64, ::Base.Iterators.Pairs{Symbol,Any,Tuple{Symbol,Symbol},NamedTuple{(:iofunction, :verbose),Tuple{getfield(HTTP.WebSockets, Symbol("##3#4")){Bool,getfield(Main, Symbol("##3#4")),String},Int64}}}, ::Function, ::Type{HTTP.ConnectionRequest.ConnectionPoolLayer{HTTP.StreamRequest.StreamLayer}}, ::HTTP.URIs.URI, ::HTTP.Messages.Request, ::Nothing) at /home/degraafc/.julia/packages/HTTP/fJZFG/src/ConnectionRequest.jl:52
 [10] (::getfield(HTTP, Symbol("#kw##request")))(::NamedTuple{(:iofunction, :reuse_limit, :verbose),Tuple{getfield(HTTP.WebSockets, Symbol("##3#4")){Bool,getfield(Main, Symbol("##3#4")),String},Int64,Int64}}, ::typeof(HTTP.request), ::Type{HTTP.ExceptionRequest.ExceptionLayer{HTTP.ConnectionRequest.ConnectionPoolLayer{HTTP.StreamRequest.StreamLayer}}}, ::HTTP.URIs.URI, ::HTTP.Messages.Request, ::Nothing) at ./none:0
 [11] (::getfield(Base, Symbol("###44#45#46")){ExponentialBackOff,getfield(HTTP.RetryRequest, Symbol("##2#3")){Bool,HTTP.Messages.Request},typeof(HTTP.request)})(::Base.Iterators.Pairs{Symbol,Any,Tuple{Symbol,Symbol,Symbol},NamedTuple{(:iofunction, :reuse_limit, :verbose),Tuple{getfield(HTTP.WebSockets, Symbol("##3#4")){Bool,getfield(Main, Symbol("##3#4")),String},Int64,Int64}}}, ::Function, ::Type, ::Vararg{Any,N} where N) at ./error.jl:203
 [12] ##44#47 at ./none:0 [inlined]
 [13] #request#1 at /home/degraafc/.julia/packages/HTTP/fJZFG/src/RetryRequest.jl:44 [inlined]
 [14] (::getfield(HTTP, Symbol("#kw##request")))(::NamedTuple{(:iofunction, :reuse_limit, :verbose),Tuple{getfield(HTTP.WebSockets, Symbol("##3#4")){Bool,getfield(Main, Symbol("##3#4")),String},Int64,Int64}}, ::typeof(HTTP.request), ::Type{HTTP.RetryRequest.RetryLayer{HTTP.ExceptionRequest.ExceptionLayer{HTTP.ConnectionRequest.ConnectionPoolLayer{HTTP.StreamRequest.StreamLayer}}}}, ::HTTP.URIs.URI, ::HTTP.Messages.Request, ::Nothing) at ./none:0
 [15] #request#1(::VersionNumber, ::String, ::Nothing, ::Function, ::Base.Iterators.Pairs{Symbol,Int64,Tuple{Symbol,Symbol},NamedTuple{(:reuse_limit, :verbose),Tuple{Int64,Int64}}}, ::Function, ::Type{HTTP.MessageRequest.MessageLayer{HTTP.RetryRequest.RetryLayer{HTTP.ExceptionRequest.ExceptionLayer{HTTP.ConnectionRequest.ConnectionPoolLayer{HTTP.StreamRequest.StreamLayer}}}}}, ::String, ::HTTP.URIs.URI, ::Array{Pair{SubString{String},SubString{String}},1}, ::Nothing) at /home/degraafc/.julia/packages/HTTP/fJZFG/src/MessageRequest.jl:47
 [16] (::getfield(HTTP, Symbol("#kw##request")))(::NamedTuple{(:iofunction, :reuse_limit, :verbose),Tuple{getfield(HTTP.WebSockets, Symbol("##3#4")){Bool,getfield(Main, Symbol("##3#4")),String},Int64,Int64}}, ::typeof(HTTP.request), ::Type{HTTP.MessageRequest.MessageLayer{HTTP.RetryRequest.RetryLayer{HTTP.ExceptionRequest.ExceptionLayer{HTTP.ConnectionRequest.ConnectionPoolLayer{HTTP.StreamRequest.StreamLayer}}}}}, ::String, ::HTTP.URIs.URI, ::Array{Pair{SubString{String},SubString{String}},1}, ::Nothing) at ./none:0
 [17] #request#1(::Int64, ::Bool, ::Base.Iterators.Pairs{Symbol,Any,Tuple{Symbol,Symbol,Symbol},NamedTuple{(:iofunction, :reuse_limit, :verbose),Tuple{getfield(HTTP.WebSockets, Symbol("##3#4")){Bool,getfield(Main, Symbol("##3#4")),String},Int64,Int64}}}, ::Function, ::Type{HTTP.RedirectRequest.RedirectLayer{HTTP.MessageRequest.MessageLayer{HTTP.RetryRequest.RetryLayer{HTTP.ExceptionRequest.ExceptionLayer{HTTP.ConnectionRequest.ConnectionPoolLayer{HTTP.StreamRequest.StreamLayer}}}}}}, ::String, ::HTTP.URIs.URI, ::Array{Pair{SubString{String},SubString{String}},1}, ::Nothing) at /home/degraafc/.julia/packages/HTTP/fJZFG/src/RedirectRequest.jl:24
 [18] (::getfield(HTTP, Symbol("#kw##request")))(::NamedTuple{(:iofunction, :reuse_limit, :verbose),Tuple{getfield(HTTP.WebSockets, Symbol("##3#4")){Bool,getfield(Main, Symbol("##3#4")),String},Int64,Int64}}, ::typeof(HTTP.request), ::Type{HTTP.RedirectRequest.RedirectLayer{HTTP.MessageRequest.MessageLayer{HTTP.RetryRequest.RetryLayer{HTTP.ExceptionRequest.ExceptionLayer{HTTP.ConnectionRequest.ConnectionPoolLayer{HTTP.StreamRequest.StreamLayer}}}}}}, ::String, ::HTTP.URIs.URI, ::Array{Pair{SubString{String},SubString{String}},1}, ::Nothing) at ./none:0
 [19] #request#5(::Base.Iterators.Pairs{Symbol,Any,Tuple{Symbol,Symbol,Symbol},NamedTuple{(:iofunction, :reuse_limit, :verbose),Tuple{getfield(HTTP.WebSockets, Symbol("##3#4")){Bool,getfield(Main, Symbol("##3#4")),String},Int64,Int64}}}, ::Function, ::String, ::HTTP.URIs.URI, ::Array{Pair{SubString{String},SubString{String}},1}, ::Nothing) at /home/degraafc/.julia/packages/HTTP/fJZFG/src/HTTP.jl:299
 [20] #request at ./none:0 [inlined]
 [21] #request#6 at /home/degraafc/.julia/packages/HTTP/fJZFG/src/HTTP.jl:313 [inlined]
 [22] #request at ./none:0 [inlined]
 [23] #open#7 at /home/degraafc/.julia/packages/HTTP/fJZFG/src/HTTP.jl:338 [inlined]
 [24] #open at ./none:0 [inlined]
 [25] #open#2(::Bool, ::Bool, ::Base.Iterators.Pairs{Union{},Union{},Tuple{},NamedTuple{(),Tuple{}}}, ::Function, ::getfield(Main, Symbol("##3#4")), ::String) at /home/degraafc/.julia/packages/HTTP/fJZFG/src/WebSockets.jl:89
 [26] open(::Function, ::String) at /home/degraafc/.julia/packages/HTTP/fJZFG/src/WebSockets.jl:80
 [27] top-level scope at none:0

[christopher-dG]

Okay so after some digging: I thought that this package was receiving a different response from the server compared to WebSockets.jl because of the thrown exception, but it turns out that they both receive the same response, but only HTTP's implementation throws an error for non-1000 status. I'll take a look at the RFC to make sure we're sending the right stuff and also check what response we should be expecting.

[christopher-dG]

5.5.1:

If an endpoint receives a Close frame and did not previously send a Close frame, the endpoint MUST send a Close frame in response. (When sending a Close frame in response, the endpoint typically echos the status code it received.)