Invalid response when body is empty

[Dennor]

Expected behaviour

HTTP/1.1 200 OK
Server: nginx
Content-Type: text/plain; charset=utf-8
Content-Length: 122
Connection: keep-alive
Keep-Alive: timeout=20
Date: Wed, 06 Dec 2017 13:13:17 GMT

When response is returned and is empty, it should stay empty.

Actual behaviour

HTTP/1.1 200 OK
Server: nginx
Content-Type: text/plain; charset=utf-8
Content-Length: 122
Connection: keep-alive
Keep-Alive: timeout=20
Date: Wed, 06 Dec 2017 13:13:17 GMT

{"id":27,"executed_at":"2017-12-06T13:13:17.344436Z","status":"success","duration":810,"result":{"stdout":"","stderr":""}}

Steps to reproduce

socket.yml

name: fail-case
description: Description of fail-case
version: 0.0.1

endpoints:
  fail-case:
    file: fail-case.js
    description: Empty response
    parameters:
    response:

src/fail-case.js

import Server from 'syncano-server';

export default async ctx => {
  const {response} = Server(ctx);
  return response('', 200, 'text/plain', {});
};

package.json

{
  "license": "MIT",
  "dependencies": {
    "syncano-server": "beta"
  },
  "devDependencies": {
    "eslint": "^4.12.1"
  }
}

Details

npx s version

0.53.0

When script returns an empty response, it replaces it with script execution info. Sometimes empty response is an expected behaviour. It can be useful for application/octet-stream and text/plain content-type responses, but it also fails at empty application/json.

[23doors]

Hey @Dennor! It seems that here the issue is not with the response being empty but with returning it from a Promise. This should work without async keyword. If you need async here - we should be able to add support for exporting async functions in a few days.

[Dennor]

import Server from 'syncano-server';

export default async ctx => {
  const {response} = Server(ctx);
  return response('text', 200, 'text/plain', {});
};

With code like this, the response I'm getting is:

HTTP/1.1 200 OK
Server: nginx
Content-Type: text/plain; charset=utf-8
Content-Length: 4
Connection: keep-alive
Keep-Alive: timeout=20
Date: Wed, 06 Dec 2017 14:05:25 GMT

text

I'm using syncano-cli@beta by the way, so async gets transpiled away.

[23doors]

As I mentioned in above comment - async here is the issue. Transpiled or not - async in export is not fully handled in terms of return response.

[Dennor]

import Server from 'syncano-server';

export default ctx => {
  const {response} = Server(ctx);
  return response('', 200, 'text/plain', {});
};

Still getting:

HTTP/1.1 200 OK
Server: nginx
Content-Type: text/plain; charset=utf-8
Content-Length: 120
Connection: keep-alive
Keep-Alive: timeout=20
Date: Wed, 06 Dec 2017 14:10:45 GMT

{"id":51,"executed_at":"2017-12-06T14:10:45.141419Z","status":"success","duration":4,"result":{"stdout":"","stderr":""}}

As I've said, every other response, except for response with empty body, as in:

return response('', 200, 'application/json', {});
return response('', 200, 'application/octet-stream', {});
return response('', 200, 'text/plain', {});

is returning, what it's supposed to be returning. When the body is empty I'm getting execution context state. Tested just now both, with and without async keyword.

[23doors]

You are right. Turns out that both handling async in backend part and incorrectly checking content are an issue here.

[Idered]

@Dennor @23doors I've removed content check as suggested in Syncano/syncano-server-js#99 . It will now always call underneath setResponse. I guess that resolves this issue. Right @Dennor ?

[mkucharz]

@Dennor @23doors are we good here?

[mkucharz]

@Dennor @23doors @Idered closing.