use default ports if empty/invalid (fixes #110)

[cvan]

my use case is wanting the port to not start at 9966 by default

see #110 (comment) and #110 (comment)

let me know if there's any way I can make this change kosher

[mattdesl]

Cool, I think this is alright since I've also been trying to find ways of using environment variables without relying on Unix-isms.

[yoshuawuyts]

Oh no, this introduces hard to debug bugs. E.g. "Why is my port 3000 if I'm passing a port variable?" Only after diving into budo source and logging values out will it be found that the port is not the one you thought you were setting, signalling a problem outside budo. budo should not do something unexpected but rather fail explicitly.

For simple use cases it might not be a problem, for more integrated solutions (who know what people use this for) this will break and bite people. 👎 we should revert this.

[mattdesl]

Hmm. I agree this can cause surprise down the line.

Is there a way to do what @cvan is doing without relying on UNIX-only shell stuff? Maybe package.json config for env vars?

[yoshuawuyts]

I think the only reliable way of getting anything done on Windows is relying on libuv / Node itself. E.g. the solution posted about using JavaScript to work around this would be valid for Windows. Though it's clunky, it's reliable. Definitely better than swallowing errors.

[cvan]

No no no, this is introduces hard to debug bugs. E.g. "Why is my port 3000 if I'm passing a port variable?" Only after diving into budo source and logging values out will it be found that the port is not the one you thought you were setting, signalling a problem outside budo. budo should not do something unexpected but rather fail explicitly.

For simple use cases it might not be a problem, for more integrated solutions (who know what people use this for) this will break and bite people. 👎 we should revert this.

budo was actually doing exactly what I didn't expect it to do - force a default port to start at without my ability to change the default.

I expected it to work like http-server (where PORT=5000 http-server starts the server at http://0.0.0.0:5000/). But budo doesn't/didn't.

[yoshuawuyts]

I expected it to work like http-server

That's a separate from this issue; arguably it would make sense that budo can act based on a BUDO_PORT variable set, with --port taking priority over that. Would that resolve your issue?

What's currently going on, however, is that instead of handling an error budo goes off and does something it shouldn't.

[mattdesl]

Ok, will revert this change back to how it was before.