ConfigService Injection Issue in Nx/NestJS Library

[ziyaDev]

Current Behavior

I created a new Nx-based NestJS library and used the ConfigService from @nestjs/config. The ConfigModule is imported in the library, and the ConfigService is injected into one of the services. However, when I use this service in a consuming NestJS app, I encounter the following error:

[Nest] 21784  - 12/01/2024, 7:33:51 AM   ERROR [ExceptionsHandler] Cannot read properties of undefined (reading 'get')

TypeError: Cannot read properties of undefined (reading 'get')
    at EnvService.getServerEnv (/Users/ziyadev/Desktop/repos/fannaq/dist/apps/testing/webpack:/packages/env/src/nestjs/env.service.ts:12:38)

This indicates that ConfigService is not properly injected, even though ConfigModule has been imported both in the library and as a global module in the app.

Expected Behavior

The ConfigService should be correctly injected into the library service, and configuration values should be accessible without errors.

GitHub Repo

No response

Steps to Reproduce

Nx Report

Node           : 20.15.1
OS             : darwin-x64
Native Target  : x86_64-macos

nx (global)        : 20.0.0
nx                 : 20.0.0
@nx/nest           : 20.0.0
@nx/workspace      : 20.0.0
@nestjs/config     : 2.3.1
typescript         : 5.5.4

Failure Logs

> nx run testing:build:development

asset main.js 11.6 KiB [emitted] (name: main) 1 related asset
asset assets/.gitkeep 0 bytes [emitted] [from: apps/testing/src/assets/.gitkeep] [copied]
orphan modules 2.77 KiB [orphan] 4 modules
runtime modules 670 bytes 3 modules
built modules 8.16 KiB [built]
  modules by path ./ 8.04 KiB
    modules by path ./apps/testing/src/app/*.ts 4.56 KiB
      ./apps/testing/src/app/app.module.ts 1.34 KiB [built] [code generated]
      ./apps/testing/src/app/app.controller.ts 1.6 KiB [built] [code generated]
      ./apps/testing/src/app/app.service.ts 1.62 KiB [built] [code generated]
    ./apps/testing/src/main.ts 665 bytes [built] [code generated]
    ./packages/env/src/nestjs/index.ts + 4 modules 2.83 KiB [not cacheable] [built] [code generated]
  modules by path external "@nestjs/ 126 bytes
    external "@nestjs/common" 42 bytes [built] [code generated]
    external "@nestjs/core" 42 bytes [built] [code generated]
    external "@nestjs/config" 42 bytes [built] [code generated]
webpack 5.96.1 compiled successfully in 7317 ms

———————————————————————————————————————————————————————————————————————————————————————————————————————————————

 NX   Successfully ran target build for project testing (13s)

Debugger listening on ws://localhost:9229/d9d08e05-e76b-4972-98e9-200ab780f2ab

Debugger listening on ws://localhost:9229/d9d08e05-e76b-4972-98e9-200ab780f2ab
For help, see: https://nodejs.org/en/docs/inspector

[Nest] 21784  - 12/01/2024, 7:33:41 AM     LOG [NestFactory] Starting Nest application...
[Nest] 21784  - 12/01/2024, 7:33:41 AM     LOG [InstanceLoader] EnvModule dependencies initialized +25ms
[Nest] 21784  - 12/01/2024, 7:33:41 AM     LOG [InstanceLoader] ConfigHostModule dependencies initialized +3ms
[Nest] 21784  - 12/01/2024, 7:33:41 AM     LOG [InstanceLoader] ConfigModule dependencies initialized +1ms
[Nest] 21784  - 12/01/2024, 7:33:41 AM     LOG [InstanceLoader] ConfigModule dependencies initialized +0ms
[Nest] 21784  - 12/01/2024, 7:33:41 AM     LOG [InstanceLoader] AppModule dependencies initialized +0ms
[Nest] 21784  - 12/01/2024, 7:33:41 AM     LOG [RoutesResolver] AppController {/api}: +11ms
[Nest] 21784  - 12/01/2024, 7:33:41 AM     LOG [RouterExplorer] Mapped {/api, GET} route +4ms
[Nest] 21784  - 12/01/2024, 7:33:41 AM     LOG [NestApplication] Nest application successfully started +3ms
[Nest] 21784  - 12/01/2024, 7:33:41 AM     LOG 🚀 Application is running on: http://localhost:3000/api
[Nest] 21784  - 12/01/2024, 7:33:50 AM     LOG [EnvService] undefined
[Nest] 21784  - 12/01/2024, 7:33:51 AM   ERROR [ExceptionsHandler] Cannot read properties of undefined (reading 'get')

TypeError: Cannot read properties of undefined (reading 'get')
    at EnvService.getServerEnv (/Users/ziyadev/Desktop/repos/fannaq/dist/apps/testing/webpack:/packages/env/src/nestjs/env.service.ts:12:38)
    at AppService.getData (/Users/ziyadev/Desktop/repos/fannaq/dist/apps/testing/webpack:/apps/testing/src/app/app.service.ts:12:32)
    at AppController.getData (/Users/ziyadev/Desktop/repos/fannaq/dist/apps/testing/webpack:/apps/testing/src/app/app.controller.ts:11:28)
    at /Users/ziyadev/Desktop/repos/fannaq/node_modules/@nestjs/core/router/router-execution-context.js:38:29
    at InterceptorsConsumer.intercept (/Users/ziyadev/Desktop/repos/fannaq/node_modules/@nestjs/core/interceptors/interceptors-consumer.js:12:20)
    at /Users/ziyadev/Desktop/repos/fannaq/node_modules/@nestjs/core/router/router-execution-context.js:46:60
    at /Users/ziyadev/Desktop/repos/fannaq/node_modules/@nestjs/core/router/router-proxy.js:9:23
    at Layer.handle [as handle_request] (/Users/ziyadev/Desktop/repos/fannaq/node_modules/express/lib/router/layer.js:95:5)
    at next (/Users/ziyadev/Desktop/repos/fannaq/node_modules/express/lib/router/route.js:149:13)
    at Route.dispatch (/Users/ziyadev/Desktop/repos/fannaq/node_modules/express/lib/router/route.js:119:3)

Package Manager Version

No response

Operating System

• macOS
• Linux
• Windows
• Other (Please specify)

Additional Information

No response

[ziyaDev]

The issue seems to be related to the SWC compiler. In the webpack.config.js, changing the compiler option from swc to tsc resolves the problem:

...
NxAppWebpackPlugin({
      target: 'node',
      compiler: 'tsc', // Switched from 'swc' to 'tsc' and the issue is gone
     ...
 
    }),

[ndcunningham]

Hi, thanks for reporting this issue.

Can you provide a small repro highlighting the issue?

NestJS has a specific requirement for monorepos, it could be that we missed something for NxAppWebpackPlugin

[ziyaDev]

Here’s a small repro along with the NxAppWebpackPlugin configuration I’m using:

const { NxAppWebpackPlugin } = require('@nx/webpack/app-plugin');
const { join } = require('node:path');

module.exports = {
  output: {
    path: join(__dirname, '../../dist/apps/testing'),
  },
  plugins: [
    new NxAppWebpackPlugin({
      target: 'node',
      compiler: 'tsc',
      main: './src/main.ts',
      tsConfig: './tsconfig.app.json',
      assets: ['./src/assets'],
      optimization: false,
      outputHashing: 'none',
      generatePackageJson: false,
      progress: false,
    }),
  ],
};

project.json:

"targets": {
    "build": {
      "executor": "@nx/webpack:webpack",
      "outputs": ["{options.outputPath}"],
      "defaultConfiguration": "production",
      "options": {
        "outputPath": "dist/apps/testing",
        "webpackConfig": "apps/testing/webpack.config.cjs",
        "main": "apps/testing/src/main.ts",
        "tsConfig": "apps/testing/tsconfig.app.json",
        "assets": ["apps/testing/src/assets"],
        "inspect": true
      },
      "configurations": {
        "development": {},
        "production": {}
      }
    },
    "serve": {
      "executor": "@nx/js:node",
      "defaultConfiguration": "development",
      "dependsOn": [
        "build",
        {
          "dependencies": true,
          "target": "build"
        }
      ],
      "options": {
        "buildTarget": "testing:build",
        "runBuildTargetDependencies": true
      },
      "configurations": {
        "development": {
          "buildTarget": "testing:build:development"
        },
        "production": {
          "buildTarget": "testing:build:production"
        }
      }
    }
  }