Refactor "unique:users,email" validation

[wimski]

The following definition exists with validation for user email uniqueness.

input RegisterInput {
    name: String! @rules(apply: ["required", "string"])
    email: String! @rules(apply: ["required", "email", "unique:users,email"])
    password: String! @rules(apply: ["required", "confirmed"])
    password_confirmation: String! @rules(apply: ["required", "string"])
    verification_url: VerificationUrlInput
}

This validation has two potential issues:

• The authenticatable model could be stored in another table than users.
• The unique identifier for the authenticatable model could be something else than email.

Further investigation is needed how to solve this.

[wimski]

@daniel-de-wit I've come to the conclusion that there is no conclusive way to dynamically determine any deviations from the standard email unique constraint. 99% of cases will have 'users' with an 'email' field that should be unique. For those that deviate, they can change the schema which should be published anyway. So I consider this a non-issue.