NestJS项目启动报错：Cannot read properties of undefined (reading 'values')

错误信息 #

[Nest] 8792  - 06/10/2023, 3:32:29 pm   ERROR [ExceptionHandler] Cannot read properties of undefined (reading 'values')
TypeError: Cannot read properties of undefined (reading 'values')
    at ./api\services\node-app\node_modules\@nestjs-plus\discovery\src\discovery.service.ts:68:50     
    at arrayMap (./api\services\node-app\node_modules\lodash\lodash.js:653:23)
    at map (./api\services\node-app\node_modules\lodash\lodash.js:9622:14)
    at Function.flatMap (./api\services\node-app\node_modules\lodash\lodash.js:9325:26)
    at new DiscoveryService (./api\services\node-app\node_modules\@nestjs-plus\discovery\src\discovery.service.ts:67:7)
    at Injector.instantiateClass (./api\services\node-app\node_modules\@nestjs\core\injector\injector.js:365:19)
    at callback (./api\services\node-app\node_modules\@nestjs\core\injector\injector.js:65:45)        
    at Injector.resolveConstructorParams (./api\services\node-app\node_modules\@nestjs\core\injector\injector.js:144:24)
    at Injector.loadInstance (./api\services\node-app\node_modules\@nestjs\core\injector\injector.js:70:13)
    at Injector.loadProvider (./api\services\node-app\node_modules\@nestjs\core\injector\injector.js:97:9)
    at Injector.lookupComponentInImports (./api\services\node-app\node_modules\@nestjs\core\injector\injector.js:289:17)
    at Injector.lookupComponentInParentModules (./api\services\node-app\node_modules\@nestjs\core\injector\injector.js:252:33)
    at Injector.resolveComponentInstance (./api\services\node-app\node_modules\@nestjs\core\injector\injector.js:207:33)
    at resolveParam (./api\services\node-app\node_modules\@nestjs\core\injector\injector.js:128:38)   
    at async Promise.all (index 0)
    at Injector.resolveConstructorParams (./api\services\node-app\node_modules\@nestjs\core\injector\injector.js:143:27)
    at Injector.loadInstance (./api\services\node-app\node_modules\@nestjs\core\injector\injector.js:70:13)
    at Injector.loadProvider (./api\services\node-app\node_modules\@nestjs\core\injector\injector.js:97:9)
    at ./api\services\node-app\node_modules\@nestjs\core\injector\instance-loader.js:56:13
    at async Promise.all (index 0)
    at InstanceLoader.createInstancesOfProviders (./api\services\node-app\node_modules\@nestjs\core\injector\instance-loader.js:55:9)
    at ./api\services\node-app\node_modules\@nestjs\core\injector\instance-loader.js:40:13
    at async Promise.all (index 33)
    at InstanceLoader.createInstances (./api\services\node-app\node_modules\@nestjs\core\injector\instance-loader.js:39:9)
    at InstanceLoader.createInstancesOfDependencies (./api\services\node-app\node_modules\@nestjs\core\injector\instance-loader.js:22:13)
    at ./api\services\node-app\node_modules\@nestjs\core\nest-factory.js:108:17
    at Function.asyncRun (./api\services\node-app\node_modules\@nestjs\core\errors\exceptions-zone.js:22:13)
    at NestFactoryStatic.initialize (./api\services\node-app\node_modules\@nestjs\core\nest-factory.js:106:13)
    at NestFactoryStatic.create (./api\services\node-app\node_modules\@nestjs\core\nest-factory.js:42:9)

排查思路 #

• 版本兼容性检查：@nestjs-plus/discovery 与当前 @nestjs/core 版本不兼容是常见原因。对照两者的官方版本说明，升级或降级到匹配的版本。
• 模块导入验证：确认是否在 AppModule（或依赖该服务的模块）中正确导入 DiscoveryModule，示例代码：

  import { DiscoveryModule } from '@nestjs-plus/discovery';
  
  @Module({
    imports: [DiscoveryModule],
    // ...其他配置
  })
  export class AppModule {}
  

• 自定义代码排查：如果有基于 @nestjs-plus/discovery 编写的自定义装饰器或服务调用，检查是否存在依赖注入错误，比如未正确注入 DiscoveryService 或调用方法时参数缺失。
• 依赖缓存清理：删除 node_modules、package-lock.json（或 yarn.lock），重新执行 npm install（或 yarn install），排除依赖包损坏或缓存冲突。

额外调试配置 #

• Node.js 详细堆栈跟踪：启动应用时添加参数，获取更完整的调用链：

  node --trace-warnings dist/main.js
  

• NestJS 日志级别调整：在 main.ts 中手动设置 verbose 级别日志，输出更多初始化细节：

  async function bootstrap() {
    const app = await NestFactory.create(AppModule, {
      logger: ['log', 'error', 'warn', 'debug', 'verbose'],
    });
    await app.listen(3000);
  }
  bootstrap();
  

• 断点调试：在 VSCode 中直接在 node_modules/@nestjs-plus/discovery/src/discovery.service.ts 第68行附近设置断点，运行调试模式，查看具体哪个变量为 undefined，定位依赖注入失败的根源。

内容的提问来源于stack exchange，提问作者Dale