serverless-offline ignores custom status code

[frsechet]

I tried to configure serverless to return a 204, but after struggling for a while and deploying, it turns out serverless offline is not handling custom status codes properly.

Using an empty function:

module.exports.hello = async () => { 
  // do nothing
};

and the following serverless.yml file:

service: test

plugins:
  - serverless-offline

provider:
  name: aws
  runtime: nodejs10.x
  stage: dev
  region: eu-west-3

functions:
  hello:
    handler: handler.hello
    events:
      - http:
          path: test
          method: GET
          integration: lambda
          cors: true
          response:
            statusCodes:
              204:
                pattern: ''

You can reproduce the issue by calling the endpoint locally:

$ curl -D - http://localhost:3000/test
HTTP/1.1 200 OK
vary: origin
access-control-allow-credentials: true
access-control-expose-headers: WWW-Authenticate,Server-Authorization
cache-control: no-cache
content-length: 0
Date: Sun, 09 Jun 2019 10:03:57 GMT
Connection: close

and deployed:

$ curl -D - https://whatever.execute-api.eu-west-3.amazonaws.com/dev/test
HTTP/1.1 204 No Content
Content-Type: application/json
Content-Length: 0
Connection: close
Date: Sun, 09 Jun 2019 10:03:24 GMT
x-amzn-RequestId: d1ba59d9-8a9d-11e9-b887-6ff35cfdb83c
Access-Control-Allow-Origin: *
x-amz-apigw-id: bAbo8FRhCGYFVgw=
X-Amzn-Trace-Id: Root=1-5cfcd96c-aecdcffcf84993249296f498;Sampled=0
X-Cache: Miss from cloudfront
Via: 1.1 e3572bc2867545c7e2bf0953e1795991.cloudfront.net (CloudFront)
X-Amz-Cf-Pop: LHR61-C1
X-Amz-Cf-Id: buAkx6Ft8RgDrCu0mMRElU2ZIR3zCFPrZzWRkRJ5wasTxB1baqFDTg==

[dherault]

Hello @frsechet, I will work on both bugs soon.

[frsechet]

No worries, thanks a lot for what you do! They are not urgent to me. I would gladly propose a PR but I am quite in a rush for now, sorry about that. I will surely contribute something over the summer :-) (and/or buy you a beer as we are both in Paris!)

Found another one while writing this one: try curl -I on both requests (offline/deployed) instead of curl -D -. Deployed generates a 403 (because there is no http event for HEAD requests), but sls-offline gladly accepts it as a GET. Would you like me to open another issue for that one?

[dherault]

Yes another issue would be nice thanks :)

[amnous]

Hi, could please let me know issue has been resolved

[FredReinink]

Hi there, this issue has come up where I work and I would like to start working on this. I was wondering if someone who has experience with the codebase or knows anything about this issue would be willing to give me some thoughts or input. Thanks.