Mongoose connection

[adamhavel]

I have an issue using Mongoose connection as shown in the provided example. I connect to MongoDB this way:

const { connection } = await mongoose.connect(`mongodb://mongo:${dbPort}/${dbName}`, {
     useUnifiedTopology: true,
     useNewUrlParser: true,
     useCreateIndex: true
});

When creating the session store, this doesn't work, because getClient doesn't return Promise but connect-mongo expects one:
clientPromise: connection.getClient()

Therefore, I have to do this:
clientPromise: Promise.resolve(connection.getClient()).

[mingchuno]

{
  // Consider this block scope, `connection` is not promise in here and show does `client`
  const { connection } = await mongoose.connect(`mongodb://mongo:${dbPort}/${dbName}`, {
       useUnifiedTopology: true,
       useNewUrlParser: true,
       useCreateIndex: true
  });
  const client = connection.getClient()
}
// if this block scope is inside an async function and what you get will be a promise

[adamhavel]

I'm not sure I understand what you are getting at. This is the official example:

const clientP = mongoose.connect(
  'mongodb://root:example@127.0.0.1:27017',
  { useNewUrlParser: true, useUnifiedTopology: true }
).then(m => m.connection.getClient())

The only reason the clientP in the example is a Promise is because it's returned by the then function which always wraps its return value in Promise.resolve. Because I'm not using Promises this way, but employ await instead, I don't get a Promise.

My point: clientPromise should internally wrap the given value with Promise.resolve and not make the user conform to one specific way of dealing with asynchrony.

[jackharrhy]

Is there an issue with clientPromise being Promise<MongoClient> | MongoClient | undefined instead of Promise<MongoClient> | undefined?

You can just as easily await mongoose.connect(... as you can mongoose.connect(...).then( it, therefore removing the need to ever be handling a Promise to a connection.

Because of clientPromise expecting a promise, I'll have to go the same route as @adamhavel and wrap it in a Promise.resolve.

[mingchuno]

Created 4.3.0 release: https://github.com/jdesboeufs/connect-mongo/blob/master/CHANGELOG.md#430---2021-03-08