Including one-to-many relationship in UserAttributes

[Thyra]

I'm using lucia with prisma in SvelteKit and my users can have permissions attached to them like so:

model User {
  id            String       @id // lucia prefers to use string IDs by default
  email         String       @unique
  password_hash String
  permissions   Permission[]
  sessions      Session[]
}

model Session {
  id        String   @id // here lucia requires it to be a string
  userId    String
  expiresAt DateTime
  user      User     @relation(references: [id], fields: [userId], onDelete: Cascade)
}

model Permission {
  id          Int     @id @default(autoincrement())
  name        String
  users       User[]
}

I would like to include these permissions in the UserAttributes so I can easily access them through the session and not load them from the DB again and again. But just naively including them in the getUserAttributes hook does not seem to work, it simply becomes undefined

export const lucia = new Lucia(adapter, {
	sessionCookie: {
		attributes: {
			secure: !dev // set to `true` when using HTTPS
		}
	},
	getUserAttributes: (attributes) => {
		return {
			email: attributes.email,
			permissions: attributes.permissions,
		};
	}
});

Is there a way to do this? (I'm on lucia v3.2.0 currently).

[Thyra]

Of course I can "manually" add them to the object but it requires an additional call to the DB and makes the downstream code uglier because I always have to await user.permissions

 async function getUserPermissions(userId) {
	const user = await prisma.user.findFirst({
		where: { id: userId },
		include: { permissions: true }
	});
	if (!user) return [];
	return user.permissions.map((permission) => permission.name);
}

export const lucia = new Lucia(adapter, {
	sessionCookie: {
		attributes: {
			secure: !dev // set to `true` when using HTTPS
		}
	},
	getUserAttributes: (attributes) => {
		return {
			// attributes has the type of DatabaseUserAttributes
			email: attributes.email,
			name: attributes.name,
			permissions: getUserPermissions(attributes.id) 
		};
	}
});