warning: possible EventEmitter memory leak detected

[DiogoDoreto]

Hello, I'm getting the following warning when testing my app:

(node) warning: possible EventEmitter memory leak detected. 11 connection listeners added. Use emitter.setMaxListeners() to increase limit.
Trace
    at Server.addListener (events.js:239:17)
    at Server._listen2 ([...]\node_modules\loopback\node_modules\continuation-local-storage\node_modules\async-listener\index.js:65:10)
    at listen (net.js:1270:10)
    at Server.listen (net.js:1366:5)
    at Test.serverAddress ([...]\node_modules\supertest\lib\test.js:56:33)
    at new Test ([...]\node_modules\supertest\lib\test.js:36:12)
    at Object.obj.(anonymous function) [as post] ([...]\node_modules\supertest\index.js:25:14)
    at test ([...]\test\models\userTest.js:264:10)
    at wrappedPromise.propagateAslWrapper ([...]\node_modules\loopback\node_modules\continuation-local-storage\node_modules\async-listener\index.js:375:23)
    at wrappedPromise.<anonymous> ([...]\node_modules\loopback\node_modules\continuation-local-storage\node_modules\async-listener\glue.js:188:31)
    at wrappedPromise.proxyWrapper [as __asl_wrapper] ([...]\node_modules\loopback\node_modules\continuation-local-storage\node_modules\async-listener\index.js:382:29)
    at [...]\node_modules\loopback\node_modules\continuation-local-storage\node_modules\async-listener\index.js:402:26
    at process._tickDomainCallback (node.js:411:9)
    at process.<anonymous> ([...]\node_modules\loopback\node_modules\continuation-local-storage\node_modules\async-listener\index.js:19:15)

Should the listener allocated on line 65 be deallocated in your library or this problem may come from the package that is using this library?

[nicolasgramlich]

@DiogoDoreto did you find a solution/workaround for this?

[DiogoDoreto]

@nicolasgramlich No, I haven't found any. It isn't critical on my case because it isn't interfering on the results of my tests, it's just an annoying message.

[Qard]

Both this issue and #29 are producing the same error and both have stack traces pointing to loopback and supertest. I suspect this has something to do with how loopback uses express and that breaks how supertest interacts with it. I'll have to investigate further, though I probably won't have time to look into it for a couple days.

This may also be an issue with loopback itself. If you haven't already, I'd recommend bringing this issue to their attention.

[dh376]

I also have problem with this...
I also use Loopback and it only happens when I do supertest.agent(app).
Someone really needs to figure out whats going on...
For now, I'm just not using supertest.agent and it works fine.

[eldh]

Don't know if this helps anyone, but I ran into this in our app that uses continuation-local-storage and worked around it by mocking it with this mock:

export default {
  getNamespace: (name) => namespaces[name] || getNamespace(),
  createNamespace: (name) => {
    namespaces[name] = getNamespace()
    return namespaces[name]
  },
}

const getNamespace = () => ({
  get: () => {},
  set: () => {},
  run: (fn) => { fn() },
  bindEmitter: () => {},
})

const namespaces = {}

[eldh]

btw I'm not using loopback.

[niftylettuce]

same issue here