Compatibility with standard-schema

[BrunnerLivio]

Is there an existing issue that is already proposing this?

• I have searched the existing issues

Is your feature request related to a problem? Please describe it

There are numerous schema validators out there. This has spawned an ecosystem around NestJS with various integrations such as nestjs-valibot and many others.

Describe the solution you'd like

NestJS could support stanadard-schema which recently hit 1.0.0:

Standard Schema is a common interface designed to be implemented by JavaScript and TypeScript schema libraries.

With that a commonly shared ValidationPipe could be offered directly from the framework instead of copy/pasting the integrations from the docs site.

Teachability, documentation, adoption, migration strategy

Guide on how to accept Standard Schema: https://standardschema.dev/#how-do-i-accept-standard-schemas-in-my-library

• Offer a general ValidationPipe that is compatible with standard-schema
• Update the docs how the ValidationPipe can be utilised with different schema libraries

What is the motivation / use case for changing the behavior?

I think it makes NestJS more future-proof with any future schema/validation library that might come

[BrunnerLivio]

Notably, there is an issue open on class-validator side around this topic as well:
typestack/class-validator#2577

[micalevisk]

I like the ideia but I think this should start as a 3rd-party lib to see community's adoption

[kamilmysliwiec]

I guess there's nothing we can do until class-validator supports the standard schema too (to avoid breaking changes)

[0x0bit]

Unfortunately, the class-validator isn't updated much anymore。typestack/class-validator#1775

[micalevisk]

@0x0bit well

[0x0bit]

@0x0bit出色地

But he didn't spend any more time in the repository; the latest update was only a month ago.

[niemyjski]

Would be nice to get standard-schema across the finish line and some resources added to class-validator. PR: typestack/class-validator#2588

[GregoireBellon]

I initiated a PR for class-validator to support the Standard Schema, and it led me to think that NestJs should not wait for it to be merged before adding support for standard-schema.

Standard Schema assumes that the validator is closely tied to the schema it uses to validate a DTO, and that a DTO can be a standard JavaScript object.

Class-validator's validator stores all validation constraints in a singleton context called "ValidationMetadata" and it relies on the DTO's constructor to identify the validation constraints related to the DTO. This means a DTO must be an instance of a class.

This difference in philosophy means that class-validator will need additional APIs to support Standard Schema's approach.

I think that building a new Validation Pipe, or adapting the current pipe to support standard-schema would be easier to maintain and faster to implement (especially since class-validator's repository does not seem not very active).

The nest-zod package basically contains all the logic we need; we just need to replace "zod" with "standard schema".

[niemyjski]

Thanks for your pr! I think it would be extremely beneficial to be apart of the core library. I think new maintainers is key and simplifying the library possibly for easier maintenance and scope.

[0x0bit]

I think that building a new Validation Pipe, or adapting the current pipe to support standard-schema would be easier to maintain and faster to implement (especially since class-validator's repository does not seem not very active).

Absolutely！！！