const mongoClient = require('mongodb').MongoClient; 
const url = 'mongodb+srv://vidya:vidya%402219@cluster0.ea8nbt4.mongodb.net'; //'mongodb://localhost:27017' 

console.log(`> Connecting to mongoDB @ ${url}`); mongoClient.connect(url, { useNewUrlParser: true, useUnifiedTopology: true }) .then(client => { if (!client) { console.log('> Failed to connect mongoDB - no client'); } else { console.log('> Connected'); db = client.db('test'); db.listCollections({ name: { $not: { $regex: /system.+$/i } } }).toArray() .then(collections => { console.log(collections); client.close(); }); } }).catch(err => { console.log(`> Failed to connect mongoDB - ${err}`); process.exit(); });

MongoServerError: can't get regex from filter doc Error parsing value [{$not [{$regex {"pattern": "system.+$", "options": "i"}}]}] to RegEx: Must specify $regex field
    at Connection.onMessage (/Users/vidyasagar/Desktop/error mongodb/node_modules/mongodb/lib/cmap/connection.js:210:30)
    at MessageStream.<anonymous> (/Users/vidyasagar/Desktop/error mongodb/node_modules/mongodb/lib/cmap/connection.js:63:60)
    at MessageStream.emit (node:events:378:20)
    at processIncomingData (/Users/vidyasagar/Desktop/error mongodb/node_modules/mongodb/lib/cmap/message_stream.js:132:20)
    at MessageStream._write (/Users/vidyasagar/Desktop/error mongodb/node_modules/mongodb/lib/cmap/message_stream.js:33:9)
    at writeOrBuffer (node:internal/streams/writable:400:12)
    at _write (node:internal/streams/writable:341:10)
    at MessageStream.Writable.write (node:internal/streams/writable:345:10)
    at TLSSocket.ondata (node:internal/streams/readable:750:22)
    at TLSSocket.emit (node:events:378:20) {
  ok: 0,
  code: 8000,
  codeName: 'AtlasError',
  [Symbol(errorLabels)]: Set(0) {}
}