how to properly expose an ES class function residing inside a module? I have a little class for loading a config file:

// index.js:

class Config {
    constructor(path) {
        this.path = path || this.defaultPath;
        this.config = fs.readFileSync(this.path, { encoding: 'utf8' });
        this.config = JSON.parse(this.config);
    }
    get() {
        return this.config;
    }
}
Config.prototype.defaultPath = './config/config.json';

module.exports = {
    Config: Config,
};


And I test it like so:

// test.js: 

const index = require('../index');

let config;

describe('config ', () =&gt; {
    before(() =&gt; {
        config = new index.Config().get();
    });
}); 


It works, but I'm wary of including a capitalized property in module.exports (mostly because I haven't seen this done before). Is there a best practice for achieving this in other ways? Should I just make the config class into its own .js file?
I'm not aware of any best practice here, so this answer is my own hunch.

I would stick with using an uppercase 'C' for the exported member name.

In JavaScript, the usual protocol is to use an uppercase name for a function that should be new from, rather than called directly e.g.

function Config()

to show that the function should be used with a new call, to treat it as a constructor. e.g.

var config = new Config();

As you are exposing a class from your module, in other words a function that can be new'd up from, then I would stick with using a capital C.