将装饰器附加到 class 会导致 Typescript:TS2539 出现错误：无法分配给“AppModule”，因为它不是变量

Question

@NgModule({
imports: [
    BrowserModule,
    UpgradeModule
]
})

export class AppModule {

    constructor(private upgrade: UpgradeModule) {
    }

    ngDoBootstrap() {
         this.upgrade.bootstrap(document.documentElement, ['ng1migrate'], {strictDi: true});
    }
}

我正在尝试从 AngularJs(1.6.6) 和双引导升级到 Angular。 当我使用 webpack4 构建项目时，它给出了错误

tsconfig.json 供参考

{

"compilerOptions": {
  "baseUrl": "",
  "declaration": false,
  "experimentalDecorators": true,
  "emitDecoratorMetadata": true,
  "lib": ["es6", "dom","ES2015"],
  "mapRoot": "./",
  "module": "es6",
  "moduleResolution": "node",
  "outDir": "../dist/out-tsc",
  "sourceMap": true,
  "target": "es5",
  "typeRoots": [
    "../node_modules/@types"
  ]
}

}

webpack.config.js 供参考

const path = require('path');

module.exports = {
    entry: './src/app/main.ts',
    output: {
      path: path.resolve(__dirname, './src/dist'),
      filename: 'bundle.js'
    },

    resolve:{
        extensions:[".webpack.js",".web.js",".ts",".tsx",".js"]
    },

    module:{
        rules:[
            {
                test: /\.ts$/,
                loader: 'ng-annotate-loader?ngAnnotate=ng-annotate-patched!ts-loader',
            },
            {test:/\.tsx?$/, use:"ts-loader"},

        ]
    },
}

版本：“ts-loader”：“^7.0.1”，“typescript”：“^3.8.3”，“webpack”：“^4.43.0”，“webpack-cli”：“^3.3.11”