OrientJS pipe exsample

orientjs-stream.js

const OrientDBClient = require("orientjs").OrientDBClient;
const fs = require("fs");
const { Transform } = require("stream");

const dbConnectionData = {
  host: "localhost",
  port: 2424
};

const dbData = {
  username: "admin",
  password: "admin",
  name: "demodb"
};

const writeStream = (session, path, query) => {
  return new Promise((resolve, reject) => {
    const file = fs.createWriteStream(path);
    let counter = 0;
    let transform = new Transform({
      objectMode: true,
      transform(transaction, encoding, callback) {
        callback(null, JSON.stringify(transaction));
      }
    });

    session
      .query(query)
      .on("data", () => counter++)
      .pipe(transform)
      .pipe(file);

    file.on("finish", () => {
      resolve(counter);
    });
  });
};

(async () => {
  const client = await OrientDBClient.connect(dbConnectionData);
  const session = await client.session(dbData);
  const results = await writeStream(session, "big.json", "select from V");

  await session.close();
  await client.close();
})();