// This code logs errors and read from collection in infinite loop
const dbServiceProvider = 'test';
const connString = 'mongodb://xxx:27017,xxx:27017,xxx:27017';
const options = {
  useNewUrlParser: true,
  useUnifiedTopology: true,
  poolSize: 2,
  ssl: true,
  authSource: 'admin',
  replicaSet: 'xxx',
  auth: { user: 'xxx', password: 'xxx' },
};
async function wait(ms) {
  return new Promise((resolve) => {
    setTimeout(resolve, ms);
  });
}
async function connect() {
  const client = await MongoClient.connect(connString, options);
  client.on('error', (error) => {
    if (error) {
      logger.fatal(error, `Event close client: ${error.message}`);
      process.exit(1);
    }
  });
  client.on('close', (info) => {
    logger.warn('CLOSING!', info);
  });
  client.on('serverClosed', (info) => {
    logger.warn('serverClosed!', info);
  });

  // reconnectFailed event works only with useUnifiedTopology = false
  client.topology.on('reconnectFailed', (error) => {
    logger.fatal(error, `reconnectFailed: ${error.message}`);
    process.exit(1);
  });
  return client.db(dbServiceProvider);
}

async function test() {
  const dbClient = await connect();
  while (true) {
    await wait(2000);
    try {
      // const loopResult = await dbManager.findOneById(dbServiceProvider, collection, result._id);
      const result = await dbClient.collection(collection).find({}).limit(1).toArray();
      // logger.info(loopResult, 'data loaded');
      console.log('data loaded');
    } catch (e) {
      logger.error(e, 'error');
    }
  }
}

test();