Idea: class-validator -> directive

[j]

I know directives aren't supported yet, but one sucky thing I've noticed is when you use class-validators and the front-end passes invalid data that fails for graphql input validation + class-validation errors, you'll get the graphql error first, then re-submit and get the class-validation error.

What would be cool is that if/when directives get supported, that the following could happen:

class Post {
  @Length(3, 50)
  @Field()
  title: string;
}

Would generate something like:

type Post {
  name: String! @ValidLength(3, 50)
}

Obviously, this is #goals, but just having directives would be a one up.

Even this would be cool:

class Post {
  @Field({ directives: "@constraint(minLength: 3, maxLength: 50)" })
  title: string;
}

And potentially allowing for:

Even this would be cool:

import { string, setup } from 'yup-type-graphql';

buildSchema({
  ...,
  directives: [setup()]
})

class Post {
  @Field({ directives: [string().min(3).max(50)] })
  title: string;
}

[MichalLytek]

the front-end passes invalid data that fails for graphql input validation + class-validation errors, you'll get the graphql error first, then re-submit and get the class-validation error

That's why you should validate your data first on the client side. And treat server validation only as a security feature for those who tries to call your mutations/queries manually.

I know directives aren't supported yet

I'm not sure if directives are evaluated just in time of validating the query against schema. Maybe you think about custom scalars?

yup-type-graphql

Yeah, I will provide integration for common libs and patterns + building blocks for making a custom ones. For now, class-validator support is hardcoded but with field metadata #124 and custom decorators #45 or middlewares, it's easy to provide this kind of integrations without relying on directives.

[MichalLytek]

Even this would be cool:

class Post {
  @Field({ directives: "@constraint(minLength: 3, maxLength: 50)" })
  title: string;
}

It's supported by #369

Even this would be cool:

import { string, setup } from 'yup-type-graphql';

buildSchema({
  // ...,
  directives: [setup()]
})

class Post {
  @Field({ directives: [string().min(3).max(50)] })
  title: string;
}

Agree but can be done by external libs like in this snippet.
You need to create standard GraphQL directives which are translated to class-validator or yup validation during directives execution.

There won't be any special built-in feature for that like for class-validator.

So closing this one 🔒