main.ts:8:7 - error TS2345: Argument of type '{ readConcern: { level: "majority"; }; writeConcern: { w: string; }; }' is not assignable to parameter of type 'MongoClientOptions'.
  Object literal may only specify known properties, and 'writeConcern' does not exist in type 'MongoClientOptions'.

8       writeConcern: { w: 'majority' },
        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


Found 1 error in main.ts:8

import { MongoClient } from 'mongodb';

async function run() {
  const client = new MongoClient(
    'mongodb://localhost',
    {
      readConcern: { level: 'majority' },
      writeConcern: { w: 'majority' },
    }
  );

  try {
    await client.connect();

    const database = client.db('test');
    const hellos = database.collection('hellos');

    const query = { name: 'abc' };
    const hello = await hellos.findOne(query);

    console.log(hello);
  } finally {
    await client.close();
  }
}
run().catch(console.dir);