We have an app running on the MEAN stack and are using MongooseJS as our ORM. Now, we have 2 collections *event* and *eventV2*. We are looking to drop the *event* collection and rename the *eventV2* collection to just *event*.

migration.js

var mongoose = require('mongoose');  
var async = require('async'); 

var db = 'mongodb://localhost/myawesomeapp';

mongoose.connect(db, function (err) {  
    if (err) { throw err; }  
    
    async.series([_dropCollection, _renameCollection], function (err, result) {  
        if (err) { throw err; }  
        console.info('Completed successfully! Result: ' + result);  
        process.exit();  
    });  
});

function _dropCollection(callback) {  
    mongoose.connection.db.dropCollection('event', function (err, result) {  
        if (err) { callback(err); }  
        callback(null, result);  
    });  
}

function _renameCollection(callback) {  
    mongoose.connection.db.renameCollection('eventV2', 'event', function (err, result) {  
        if (err) { callback(err); }  
        callback(null, result);  
    });  
}