Is there an existing issue for this?

• I have searched the existing issues

Current behavior

In issue #12264, we discussed problems with types related to ReflectableDecorator and CreateDecoratorOptions.transform.
However, this has not been fixed everywhere. There may be other functions, but I only found Reflector.getAllAndOverride, Reflector.getAll and Reflector.getAllAndMerge.
Here is an example of a fix:

function getAllAndOverride<TParam = any, TTransformed = TParam, T extends ReflectableDecorator<TParam, TTransformed>>(
    decorator: T,
    targets: (Type<any> | Function)[],
): T extends ReflectableDecorator<infer RParam, infer RTransformed> ? RTransformed : unknown;
// to
function getAllAndOverride<
    TParam = any,
    TTransformed = TParam,
    T extends ReflectableDecorator<TParam, TTransformed> = ReflectableDecorator<any>,
>(
    decorator: T,
    targets: (Type<any> | Function)[],
): T extends ReflectableDecorator<infer RParam, infer RTransformed> ? RTransformed : unknown;

Minimum reproduction code

Steps to reproduce

No response

Expected behavior

Ideally, the typing system would be able to detect the return value on the transform property, and use that as the return value of the Refector methods.

Package

• I don't know. Or some 3rd-party package
• @nestjs/common
• @nestjs/core
• @nestjs/microservices
• @nestjs/platform-express
• @nestjs/platform-fastify
• @nestjs/platform-socket.io
• @nestjs/platform-ws
• @nestjs/testing
• @nestjs/websockets
• Other (see below)

Other package

No response

NestJS version

10.3.7

Packages versions

10.3.7

Node.js version

20.8.1

In which operating systems have you tested?

• macOS
• Windows
• Linux

Other

No response