Test cursor hasNext

index.spec.js

const { MongoClient } = require('mongodb');
const assert = require('assert');

describe('mongodb cursor issue', function() {
  this.timeout(2000);

  let client;
  let dbName;
  let db;
  let collection;

  beforeEach(async () => {
    dbName = `test-${Date.now()}`;
    client = await MongoClient.connect(
      'mongodb://localhost:27017',
      { useUnifiedTopology: true }
    );

    db = client.db(dbName);
    collection = db.collection('coll1');
  });

  afterEach(async () => {
    await db.dropDatabase();
    client.close(true);
  });

  it('should fetch the right document range', async() => {
    await collection.insertMany([
      {doc: 1},
      {doc: 2},
      {doc: 3}
    ]);

    const cursor = collection
      .find({}, { projection: { _id: 0 }})
      .skip(1)
      .limit(1);

    const results = [];

    while(await cursor.hasNext()) {
      results.push(await cursor.next());
    }

    assert.deepEqual(results, [{doc: 2}]);
  });
});

package.json

{
  "name": "test-cursor-hasnext",
  "version": "1.0.0",
  "main": "index.js",
  "license": "MIT",
  "dependencies": {
    "mongodb": "3.5.4"
  },
  "scripts": {
    "test": "mocha index.spec.js"
  },
  "devDependencies": {
    "mocha": "^7.1.0"
  }
}