Model.create in a transaction

With the recent introduction of transactions, various methods now accept an additional session option. Unfortunately it made things a bit tricky for Model.create.

Model.create accepts options only if given an array. This means that a simple statement like this:

const instance = await SomeModel.create({
  prop1: true,
  prop2: 123
});

now becomes:

const instance = (await SomeModel.create([{
  prop1: true,
  prop2: 123
}], {session: ...}))[0];

It’s becoming hard to read, so it would be awesome if there would be a way to create a single document without having to pass an array.

[c-eliasson]

@mushfau that’s because the create method accepts either an array of docs, or 1-n docs as a spread. Mongoose can’t differentiate between your options object and an intended doc. It thinks your options object is yet another document you want to insert, but since no properties match you schema, the only thing inserted is the _id.

The docs actually mention this:

To specify options, docs must be an array, not a spread.

[vkarpov15]

@c-eliasson the ‘cannot create namespace’ error is a pretty common pain point when testing with transactions. You can use Model.createCollection() or the autoCreate option to work around this.

And re: SomeModel(obj).save(session), that was a typo that I fixed. It should be SomeModel(obj).save({ session }), see docs. Sorry about the confusion.