Connect Firebase Realtime Database and Send email in our serverless environment

class FirebaseSourceGetFromRealtimeDb {
    async init() {
        // TODO: Create your firebase credential
        // More info at https://yepcode.io/docs/integrations/firebase/#credential-configuration
        this.firebase = yepcode.integration.firebase(
            "your-firebase-credential-name"
        );
        this.db = getDatabase(this.firebase);
        this.dbRef = ref(this.db);
    }

    async fetch(publish, done) {
        // TODO: Customize the path to the firebase object
        const snapshot = await get(child(this.dbRef, "/path-to-the-objects"));
        if (snapshot.exists()) {
            for (const item of Object.values(snapshot.val())) {
                await publish(item);
            }
        }
        done();
    }

    async close() {
        deleteApp(this.firebase);
    }
}

class SmtpTargetSendEmail {
    async init() {
        // TODO: Create your smtp credential
        // More info at https://yepcode.io/docs/integrations/smtp/#credential-configuration
        this.nodemailer = yepcode.integration.smtp("your-smtp-credential-name");
        this.items = [];
    }

    async consume(item) {
        // we save the items for later
        this.items.push(item);
        // we could send a mail per item here if we want to
    }

    async close() {
        // we want to send a resume mail so we send it at the end
        // TODO: Customize email content
        const text = `Here are the items we got:
    ${this.items.map((item) => ` * ${item.id}: ${item.name}`).join("\n")}`;
        // TODO: Customize email params: from, to and subject
        await this.nodemailer.sendMail({
            from: "your-email@example.com",
            to: "the-target@example.com",
            subject: `Choose your subject`,
            text,
        });
    }
}