Type helpers loose class-validator/class-transformer metadata in Yarn PnP environments

Is there an existing issue for this?

• I have searched the existing issues

Current behavior

@nestjs/swagger uses @nestjs/mapped-types which uses class-validator and class-transformer (if they’re present) to inherit validation/transformer metadata.

1. @nestjs/swagger brings @nestjs/mapped-types as dependency.
2. @nestjs/mapped-types requires class-validator and class-transformer as optional peer dependencies.
3. @nestjs/swagger doesn’t provide class-validator and class-transformer.
4. @nestjs/swagger -> @nestjs/mapped-types checks whether class-validator and class-transformer are present, sees that they aren’t and doesn’t inherit metadata (ref).

Yarn PnP doesn’t allow implicit requirements which may cause undefined behaviour. It means Yarn PnP expects from @nestjs/swagger to satisfy @nestjs/mapped-types peer/optional dependencies since it’s the direct dependency.

Minimum reproduction code

https://gist.github.com/khmm12/c2a4bdab7dfa82d33f06c45a768ad6d7

Steps to reproduce

No response

Expected behavior

I see 2 possible solutions:

• @nestjs/swagger should specify @nestjs/mapped-types as peer dependency instead of dependency.
• @nestjs/swagger should specify class-validator and class-transformer as optional dependencies.

Package version

6.13

NestJS version

No response

Node.js version

No response

In which operating systems have you tested?

• macOS
• Windows
• Linux

Other

No response

[kamilmysliwiec]

Thanks for chiming in & clarifying @arcanis, and for a thorough discussion @khmm12. Appreciate your time!

Since it doesn’t hurt to explicitly add the inner package’s peer dependencies, let’s just add them in to be compatible with Yarn PnP. Would you like to create a PR @khmm12? Let me know if you’re busy and if so I’ll take care of this myself!

[khmm12]

@kamilmysliwiec I’ll create PRs for @nestjs/swagger and @nestjs/graphql 👍