mongodb-nodejs-driver, DeprecationWarning: collection.count is deprecated

I want to get the count of posts documents using:

db.collection('posts').count()

But, I got a warning:

DeprecationWarning: collection.count is deprecated, and will be removed in a future version. Use collection.countDocuments or collection.estimatedDocumentCount instead

Here is my mongodb nodejs driver version:

  "dependencies": {
    "mongodb": "^3.1.0"
  },
  "devDependencies": {
    "@types/mongodb": "^3.1.0",
    "chai": "^4.1.2",
    "mocha": "^5.1.1",
    "ts-node": "^7.0.0",
    "tslint": "^5.10.0",
    "typescript": "^2.9.2"
  }

There is no countDocuments or estimatedDocumentCount in index.d.ts file.

How can I solve this warning?

Solution

As you figured out, starting from MongoDB Node.JS driver v3.1 the count() method has been deprecated and will be replaced with :

These methods have been added to node-mongodb-native package itself. For example, via the MongoDB Node.JS driver you should be able to do:

db.collection("posts").countDocuments(
  {}, // filters
  {}, // options
  function(error, result) {
    console.log(result);
  }
);