Avoid restarting server in development when changed file(s) not used by server bundle.

[benjamn]

Most importantly, this change means that changes to files not used by the server bundle will not trigger a server restart.

Fixes #10449 by implementing the strategy I described in this comment: #10414 (comment)

[pmogollons]

@benjamn this is an awesome improvement. Got the full page reload time from 8s to 5s.

Is there a way to be able to include something like this in a module that is loaded on server and client and still get the benefits?

// /startup/both/index.js

import { Meteor } from 'meteor/meteor';

if (Meteor.isProduction) {
  require('./routes');
}

import './slingshot';
import './registerApi';

Just having there the require or the import makes the server to restart even if not actually imported.

[benjamn]

@pmogollons Great to hear it's working so well!

I would love your help testing a slightly simpler implementation of this functionality, coming soon (probably in 1.8.2-rc.7), once #10763 is merged.

To answer your question, in Meteor 1.8.3, we want to tackle tree shaking / dead code elimination, which involves pruning the dependency tree while scanning imports in the ImportScanner. I believe it should be possible to treat values like Meteor.isProduction as constants during this process, and eliminate those branches if their conditions are false, so that the ./routes dependency would not show up at all in the production bundle.