feat: nested type proposal

[ibellver]

Currently without using the class-transformer there is no option to work with the nested elements and also with troubles related with this typestack/class-transformer#563

This is a proposal to create a decorator for that purpose without depending on class-transformer, when you are using only class-validator decorators

Usage

@ValidateNested()
@NestedType(() => NestedClass)
nestedTypeWithObject: NestedClass | null | undefined;

@ValidateNested({ each: true })
@NestedType(() => NestedClass)
nestedTypeWithArray: NestedClass[]

The decorator is not altering the previous behavior, so, no regressions or breaking changes are expected. The decorator is only taken into account when present in a class attribute, in that case, it will have preference when detecting the nested type.

The name of the decorator is only a proposal

I hope you find this useful
Greetings 😄

[ibellver]

There is also an alternative, problably cleaner and more aligned with the library. Instead of a new decorator we can just add a new property to the current options of the @JSONSchema decortator.

Something like

@ValidateNested({ each: true })
@JSONSchema({
    nestedType: () => NestedClass
})
nestedTypeWithArray: NestedClass[]

If you see it's interesting I can implement that approach.