Add createConnection option for http or https requests

[xv2]

Hi,
I need a possibility of using createConnection option in the http/https request:

createConnection A function that produces a socket/stream to use for the request when the agent option is not used. This can be used to avoid creating a custom Agent class just to override the default createConnection function. See agent.createConnection() for more details. Any Duplex stream is a valid return value.

You can read more info about this function in the Node.js documentation: https://nodejs.org/api/http.html#http_http_request_options_callback

NOTE: The createConnection of globalAgent isn't suitable for me because I use other connections

P.S. Thanks for your work and the best library for EventSource.

[aslakhellesoy]

Is this functionality in the spec? If not, why do you think we should deviate from the spec?

[xv2]

Of course this option isn't in EventSource specification. This option (createConnection) is only for Node.js® as other your options (in your code): proxy, rejectUnauthorized ...

[aslakhellesoy]

I suppose we could add it as a non-standard property on the eventSourceInitDict object. Any objections from anyone?

@xv2 send a pull request and we can discuss it.

[xv2]

@aslakhellesoy PR: #120

[thedillonb]

This would be extremely helpful as there doesn't currently seem to be a way to use UNIX domain sockets with this library.

[thedillonb]

Can we get a ruling on this?