BSON serialization from getServerSideProps

[arnaudriegert]

Feature request

Is your feature request related to a problem? Please describe.

getServerSideProps has been a huge help, and it would be an even bigger one if it allowed us to return objects containing BSON, for instance results from a query to a MongoDB database.

Describe the solution you'd like

I would like the serializer that's called at the end of getServerSideProps to handle BSON just like the one called in API routes when I do res.json(...).

Describe alternatives you've considered

Right now, in getServerSideProps I call an API route that does the database fetching and the serializing, so that I can insert the json from that route into the returned props.
But it won't work, for instance, when I want to serialize context.req.user which I define in my authentication middleware.

The alternative would be to call manually a BSON-compatible serializer before returning the props. But since Next.js seems to already have on at hand for the API routes, I thought maybe we could just use the same one.

[arnaudriegert]

Ok I just realized that the serializer on the API routes was just JSON.stringify.

So for instance in my case this works:

export const getServerSideProps = async (context) => {
  return { user: JSON.parse(JSON.stringify(context.req.user)) }
}

but this doesn't:

export const getServerSideProps = async (context) => {
  return { user: context.req.user }
}

It would be nice if we could use the second syntax :)

[timneutkens]

You can read more about why this is the behavior here: #12156 (comment)

It's there to prevent you from introducing hydration bugs