Cannot extend ValidationPipe properly

[bombard1004]

Is there an existing issue for this?

• I have searched the existing issues

Current behavior

I'm trying to extend ValidationPipe to create a CustomPipe, but I've noticed that the injection of the CustomPipe doesn't work properly.

Specifically, even though there is no provider for the first parameter of CustomPipe, Nest ignores it. If the provider exists, the injection works fine.

I believe this is because the @Optional() applied to the first parameter of ValidationPipe is applied to the subclass (CustomPipe) as well. This seems to happen because @Optional stores the index of the parameter in the metadata.

Minimum reproduction code

https://stackblitz.com/edit/nestjs-typescript-starter-ktzqni?file=src%2Fapp.module.ts,src%2FcustomPipe.ts

Steps to reproduce

1. npm install && npm start
2. see error

Expected behavior

I think Nest should prevent @Optional from propagating to child classes so that the injection of child classes can be done correctly, because the same problem occurs when we try to extend any class that uses @Optional, not just ValidationPipe.

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

10.2.6

Packages versions

{
  "name": "nest-typescript-starter",
  "private": true,
  "version": "1.0.0",
  "description": "Nest TypeScript starter repository",
  "license": "MIT",
  "scripts": {
    "build": "nest build",
    "format": "prettier --write \"src/**/*.ts\" \"test/**/*.ts\"",
    "start": "nest start",
    "start:dev": "nest start --watch",
    "start:debug": "nest start --debug --watch",
    "start:prod": "node dist/main",
    "lint": "eslint \"{src,apps,libs,test}/**/*.ts\" --fix",
    "test": "jest",
    "test:watch": "jest --watch",
    "test:cov": "jest --coverage",
    "test:debug": "node --inspect-brk -r tsconfig-paths/register -r ts-node/register node_modules/jest/bin/jest --runInBand",
    "test:e2e": "jest --config ./test/jest-e2e.json"
  },
  "dependencies": {
    "@nestjs/common": "^10.0.0",
    "@nestjs/core": "^10.0.0",
    "@nestjs/platform-express": "^10.0.0",
    "reflect-metadata": "^0.1.13",
    "rxjs": "^7.8.1"
  },
  "devDependencies": {
    "@nestjs/cli": "^10.0.1",
    "@nestjs/schematics": "^10.0.1",
    "@nestjs/testing": "^10.0.0",
    "@swc/cli": "^0.1.62",
    "@swc/core": "^1.3.64",
    "@types/express": "^4.17.17",
    "@types/jest": "^29.5.2",
    "@types/node": "^20.3.1",
    "@types/supertest": "^2.0.12",
    "@typescript-eslint/eslint-plugin": "^5.59.11",
    "@typescript-eslint/parser": "^5.59.11",
    "eslint": "^8.42.0",
    "eslint-config-prettier": "^8.8.0",
    "eslint-plugin-prettier": "^4.2.1",
    "jest": "^29.5.0",
    "prettier": "^2.8.8",
    "source-map-support": "^0.5.21",
    "supertest": "^6.3.3",
    "ts-jest": "^29.1.0",
    "ts-loader": "^9.4.3",
    "ts-node": "^10.9.1",
    "tsconfig-paths": "^4.2.0",
    "typescript": "^5.1.3"
  },
  "jest": {
    "moduleFileExtensions": [
      "js",
      "json",
      "ts"
    ],
    "rootDir": "src",
    "testRegex": ".*\\.spec\\.ts$",
    "transform": {
      "^.+\\.(t|j)s$": "ts-jest"
    },
    "collectCoverageFrom": [
      "**/*.(t|j)s"
    ],
    "coverageDirectory": "../coverage",
    "testEnvironment": "node"
  }
}

Node.js version

18.18.0

In which operating systems have you tested?

• macOS
• Windows
• Linux

Other

No response

[kamilmysliwiec]

#2581