Error when running karma without internet connection

Expected behavior

I would expect to be able to run unittests even when I do not have an internet connection available. My internet provider decided to ditch my connection today, I was working from home and I thought well, while they fix this I’ll go write some more unittests. No go. Apparently something goes wrong when it tries to lookup address information (which is not available).

Actual behavior

I get the following error:

C:\Users\project_name\node_modules\karma\lib\runner.js:65
      throw e
      ^

Error: getaddrinfo ENOENT localhost:9877
    at Object.exports._errnoException (util.js:849:11)
    at errnoException (dns.js:31:15)
    at GetAddrInfoReqWrap.onlookup [as oncomplete] (dns.js:77:26)

Enviroment Details

• Karma version (output of karma --version): 0.13.22 (reproducible on 1.3.0)
• Relevant part of your karma.config.js file: None
• Other info:
• Running Windows 10.
• Running this in Webstorm 11 (though it also happens running CLI commands).

See: https://github.com/RobertDiebels/karma-test/tree/master for further details.

Steps to reproduce the behaviour

1. Disconnect from all your networks.
2. run command karma start
3. run command karma run --conf karma.conf.js --file jasmine-test.spec.js
4. Behold the error message

This is reproducible on Karma version: 1.3.0 just ran the steps above again.

[maksimr]

I can confirm that problem exist, but problem in karma run command only

karma start work as expected, karma run does not work if disable network

[yaacovCR]

Consider node-offline-localhost.

Add the following before the breaking code:

require('node-offline-localhost').always();

And it just works (hopefully), at least until RFC 3493 gets fixed.

Full disclosure: I authored this package to streamline https in my dev environment when offline.