How do I structure Cloud Functions for Firebase to deploy multiple functions from multiple files?

Question

I would like to create multiple Cloud Functions for Firebase and deploy them all at the same time from one project. I would also like to separate each function into a separate file. Currently I can create multiple functions if I put them both in index.js such as:

exports.foo = functions.database.ref('/foo').onWrite(event => {
    ...
});

exports.bar = functions.database.ref('/bar').onWrite(event => {
    ...
});

However I would like to put foo and bar in separate files. I tried this:

/functions
|--index.js (blank)
|--foo.js
|--bar.js
|--package.json

where foo.js is

exports.foo = functions.database.ref('/foo').onWrite(event => {
    ...
});

and bar.js is

exports.bar = functions.database.ref('/bar').onWrite(event => {
    ...
});

Is there a way to accomplish this without putting all functions in index.js?

Answer 1

Ah, Cloud Functions for Firebase load node modules normally, so this works

structure:

/functions
|--index.js
|--foo.js
|--bar.js
|--package.json

index.js:

const functions = require('firebase-functions');
const fooModule = require('./foo');
const barModule = require('./bar');

exports.foo = functions.database.ref('/foo').onWrite(fooModule.handler);
exports.bar = functions.database.ref('/bar').onWrite(barModule.handler);

foo.js:

exports.handler = (event) => {
    ...
};

bar.js:

exports.handler = (event) => {
    ...
};