coro-http does not generate error nor returns when remote immediately closes the connection

[edubart]

When doing a HTTP request with coro-http and the remote immediately closes the connection without a response the coroutine never returns, ideally it should throw an error.

Test exampe:

local http = require 'coro-http'
coroutine.wrap(function()
  local ok, err = pcall(function()
    http.request('GET', 'http://www.google.com:443/')
  end)
  if ok then print('success')
  else print('error:', err) end
end)()

In the above example because we are forcing connecting to port 443 (the https port) while using HTTP protocol the remote will imediatelly close the connection because of invalid protocol.

When running with luvit the above example ends with no messages, it should print the error instead.

[SinisterRectus]

There is a bit of a descrepency between how errors are handled between some of the coro packages. Some return nil, err, some throw the error. Changing this now may break things, though.

HTTP responses are a little different though since the code and reason are in the response metadata table. Depending upon the server, you may also get more information in the response body.

[creationix]

I like the assert style error handling because it gives the caller the option to ignore errors without having to use error catching. Generally I only like to throw hard errors in cases of user error (invalid argument types, for example), but things that are outside the control of the programmer (like a website being down) are a different type of error and I like the soft error in returning nil, err.

[SinisterRectus]

I agree, I prefer that style.

Some discrepancies I am referring to are:

• coro-http asserts net.connect, coro-websocket does not
• there are error calls in the websocket handshake closure, but the handshake and websocket.connect use the nil, err style. I'm not sure if this is an oversight.

[creationix]

I'd be fine with PRs making it more consistent. We can bump major versions if it's a breaking change.

[SinisterRectus]

I'll see what I can do then. It'll take some time to deconstruct everything, but it shouldn't be too challenging.