app.js

const MongoClient = require('mongodb').MongoClient;
const assert = require('assert');
const circulationRepo = require('./repos/circulationRepo');
const data = require('./circulation.json');

const url = "mongodb://localhost:27017";
const dbName = "circulation";

async function main() {
  const client = new MongoClient(url);
  await client.connect();

  try {
    const results = await circulationRepo.loadData(data);
    assert.equal(data.length, results.insertedCount);

    const getData = await circulationRepo.get();
    assert.equal(data.length, getData.length);

    const filterData = await circulationRepo.get({Newspaper: getData[4].Newspaper}); 
    assert.deepEqual(filterData[0], getData[4]);

    const limitData = await circulationRepo.get({}, 3);
    assert.equal(limitData.length, 3);

    const id = getData[4]._id.toString();
    const byId = await circulationRepo.getById(id);
    assert.deepEqual(byId, getData[4]);

    const newItem = {
      "Newspaper": "My paper",
      "Daily Circulation, 2004": 1,
      "Daily Circulation, 2013": 2,
      "Change in Daily Circulation, 2004-2013": -100,
      "Pulitzer Prize Winners and Finalists, 1990-2003": 44,
      "Pulitzer Prize Winners and Finalists, 2004-2014": 41,
      "Pulitzer Prize Winners and Finalists, 1990-2014": 85
  };
  const addedItem = await circulationRepo.add(newItem);
  assert(addedItem._id);
  const addedItemQuery = await circulationRepo.getById(addedItem._id);
  assert.deepEqual(addedItemQuery, newItem);

  const updatedItem = await circulationRepo.update(addedItem._id,  {
    "Newspaper": "My new paper",
    "Daily Circulation, 2004": 1,
    "Daily Circulation, 2013": 2,
    "Change in Daily Circulation, 2004-2013": -100,
    "Pulitzer Prize Winners and Finalists, 1990-2003": 44,
    "Pulitzer Prize Winners and Finalists, 2004-2014": 41,
    "Pulitzer Prize Winners and Finalists, 1990-2014": 85
});

assert.equal(updatedItem.Newspaper, "My new paper");
const newAddedItemQuery = await circulationRepo.getById(addedItem._id);
  assert.equal(newAddedItemQuery.Newspaper, "My new paper");

const removed = await circulationRepo.remove(addedItem._id);
assert(removed);
const deletedItem = await circulationRepo.getById(addedItem._id);
assert.equal(deletedItem, null);

const avgFinalists = await circulationRepo.averageFinalists();
console.log('Average Finalists: ' + avgFinalists);

const avgByChange = await circulationRepo.averageFinalistsByChange();
console.log(avgByChange);

  } catch (error) {
        console.log(error);
  } finally {
    const admin = client.db(dbName).admin();

    await client.db(dbName).dropDatabase();
    console.log(await admin.listDatabases());

    client.close();
  }
}

main();