make it work for mounted folders

[xiankai]

I was trying to get this to work in conjunction with the jspm hot reloader. However with my project on a shared folder in the VM, the file change events were not being emitted.

After doing some checking, I chanced upon paulmillr/chokidar#242 and it turns out that it's a known issue that requires a simple configuration change.

[capaj]

@xiankai thanks for reporting this. I don't develop on mounted drives so I never ran into it. I am a bit hesitant to merge this because chokidar performs better when not polling for changes.
Do you think that it would be possible to make sure that the base folder is mounted with https://www.npmjs.com/package/node-df and then enable it only if true?
I want to introduce .chokidar or some similar config like that which might be used to configure chokidar even more. But if we can make it smart even without any configs, I think we should try.

[xiankai]

Sorry, I didn't know there was a performance drawback to the config change. As for node-df, I am not sure how that package works, but in my case (using vagrant on virtualbox), it is virtualbox that is mounting the folder and thus kinda out of the scope of the VM. Additionally, I'm not sure if there's an easy way to check whether the folder is mounted or not (Docker and other VM providers come to mind, too many different cases).

I am definitely in favor of a config file though.

[capaj]

@xiankai the simplest solution was to extend chokidar options with a chokidar prop from opts. So version 0.2.1 should resolve this issue.
Just use

chokidarEvEmitter({port: 8090, path: '.', chokidar: {usePolling: true}})

wherever you're calling chokidar-scoket-emitter