Unique Constraints
👨💼 We have a
@unique constraint on several fields. The id is fine because
that's either generated by the database or hard-coded. But the username and
email fields are generated by faker which can technically generate the same
values twice in a row. Here's how we're doing it currently:export function createUser() {
const firstName = faker.person.firstName()
const lastName = faker.person.lastName()
const username = faker.internet.userName({
firstName: firstName.toLowerCase(),
lastName: lastName.toLowerCase(),
})
return {
username,
name: `${firstName} ${lastName}`,
email: `${username}@example.com`,
}
}
If faker generated the same first and last name then we'd be in trouble. Our
seed script would fail to create a user.
So let's fix that with
enforce-unique. Here's an
example of how to use this:const uniqueEmailEnforcer = new UniqueEnforcer()
const email = uniqueEmailEnforcer.enforce(() => faker.internet.email())
On top of that, it's possible the username is too long or the wrong case. We're
going to want to limit usernames in our app to be lower case, only 20
characters, and alphanumeric. So we'll want to do something about that as well.
Can you deal with these things? The emoji should help guide you through this.
🐨 When you're ready to go, run the seed script:
npx prisma db seed
🐨 And then open up the Prisma Studio to see your generated data:
npx prisma studio