I can't module.exports more than 1 function

Question

If I do the following:

// at the end of database.js
module.exports = mongoConnect;
module.exports = getDb;

// app.js
const mongoConnect = require('./util/database').mongoConnect;
mongoConnect();

I get the error: ERROR: mongoConnect is not a function.

But if I instead export them like this:

// at the end of database.js
module.exports = {
    mongoConnect,
    getDb,
};

Then running console.log(mongoConnect) in app.js gives the following:

{
    mongoConnect: [Function: mongoConnect],
    getDb: [Function: getDb],
}

and app.js can use mongoConnect just fine.

Why can't I use the first format?

Answer 1

You are overwriting the exports, thus only the last value is saved. Besides, when directly assigning exports, then require('...') will be that exact exports.

Your second example is how you're meant to export multiple values:

// module
module.exports = {
    mongoConnect,
    getDb,
};

// other module
const module = require('./module');
module.getDb(...);

// or alternatively
const { getDb } = require('./module');
getDb(...);