Generate Firestore backup

backup.ts

export async function exportData(projectId: string, clientEmail: string, privateKey: string) {
    const timestamp = moment().format('YYYY-MM-DD_x');
    const name = `projects/${projectId}/databases/(default)`;
    const outputUriPrefix = `gs://${projectId}.appspot.com/backups/${timestamp}`;

    const fsAdmin = new v1.FirestoreAdminClient({
        projectId,
        credentials: {
            client_email: clientEmail,
            private_key: privateKey
        }
    });

    return new Promise((resolve, reject) => {
        fsAdmin.exportDocuments({ name, outputUriPrefix }, (err: Error, operation: any) => {
            if (err) {
                reject(err);
            } else {
                console.log(`Long running operation: ${operation.name}`);
                resolve(outputUriPrefix);
            }
        });
    });
}