How to create nested validations

[iagomelanias]

Describe the issue
Hello! 👋
I'm trying to validated InputType. A specific field has it's own type. It looks like below:

@InputType()
export class RecipeInput {
  @Field()
  @Type(() => AuthorInput)
  author: AuthorInput;
}

The CustomerInput looks like this:

@InputType()
export class AuthorInput {
  @Field()
  @Length(1, 255)
  firstName: string;
}

TypeGraphQL builds the schema correctly, but class-transformer does not validate the nested input. I also tried to add the @ValidateNested decorator, but i get the following error:

"constraints": {
  "nestedValidation": "nested property customer must be either object or array"
}

Error: Argument Validation Error,
  at Object.<anonymous> (/Users/iago/Drive/Code/api/node_modules/type-graphql/resolvers/validate-arg.js:21:19),
  at Generator.throw (<anonymous>),
  at rejected (/Users/iago/Drive/Code/api/node_modules/tslib/tslib.js:105:69),
  at process.internalTickCallback (internal/process/next_tick.js:77:7)

I found a test case which contains a nested input type, but i didn't find any test case using validations.

As mentioned in this comment, it looks like the nested object is not converted to AuthorInput class, the property author is [Object: null prototype].

So, with the current limitations, is there any way to implement a nested validation?

Are you able to make a PR that fix this?
I don't think so, but i can add some test cases to ensure this is properly covered.

Additional context

• TypeGraphQL Version: 0.15.0
• Node Version: v11.1.0

[MichalLytek]

The test case is only for schema generation, not for runtime instance check nor nested validation (unfortunately).

So closing this as duplicate of #133 🔒

As a temporary workaround you need to perform the validation manually in resolvers, I think that class-transformer-validator would be the best (one-liner).