SImple Rest Api with Firestore and Functions

marvel.js

const functions = require('firebase-functions');

const admin = require('firebase-admin');
admin.initializeApp();

exports.marvel = functions.https.onRequest(async (req, res) => {
	try {
		const listResult = await admin.firestore()
					.collection('marvel')
					.get()
					.then(snapshot => snapshot.docs.map(x => x.data()))
		res.json({ data: listResult })
	} catch (e) {
		const message = e.message;
		res.json({ data: null, error: message });
	}
});