Clean up null values in mongo

clean-up-nulls-in-mongo.js

const collectionNames = db.getCollectionNames();

for (const name of collectionNames) {
  var coll = db.getCollection(name);
  var cursor = coll.find();
  while (cursor.hasNext()) {
    var doc = cursor.next();
    var keys = {};
    var hasNull = false;
    for (var x in doc) {
      const json = JSON.stringify()
      if (x != "_id" && (doc[x] == null || (Array.isArray(doc[x]) && doc[x].length == 0) || (typeof doc[x] === 'object' && Object.keys(doc[x]).length == 0 ) )) {
        keys[x] = 1;
        hasNull = true;
      }
    }
    if (hasNull) {
      coll.updateOne({ _id: doc._id }, { $unset: keys });
    }
  }
}