AOT NgModule provider with dependencies, NullInjectorError

问题

I've tried the implementation in https://stackoverflow.com/a/43293449/513570:

@NgModule()
export class SampleModule {
  static forRoot(config: CustomConfig): ModuleWithProviders {
    // User config get logged here
    console.log(config);
    return {
      ngModule: SampleModule,
      providers: [SampleService, {provide: 'config', useValue: config}]
    };
  }
}

@Injectable()
export class SampleService {

  constructor(@Inject('config') private config:CustomConfig) {

const sConfig = {
    key: 'value'
};


@NgModule({
    declarations: [
        ...
    ],
    imports: [
        BrowserModule,
        HttpModule,
        IonicModule.forRoot(MyApp),
        IonicStorageModule.forRoot(),
        SampleModule.forRoot(sConfig),
    ],
    bootstrap: [IonicApp],
    entryComponents: [
        ...
    ],
    providers: [
        ...,
        // { provide: SampleService, useFactory: () => new SampleService(sConfig) 
    ],
})
export class AppModule { }

If the service is imported in providers (commented code) instead of imports, all works fine in development and AOT.

But the given code only code works fine in development mode. In AOT it raises the following error:

StaticInjectorError[l]: 
  StaticInjectorError[l]: 
    NullInjectorError: No provider for l!

I've been serving with live-reload and preserve log in chrome while compiling the app and at some point (before mangling I suppose) the error is:

StaticInjectorError[SampleService]: 
  StaticInjectorError[SampleService]: 
    NullInjectorError: No provider for SampleService!

I've also tried to provide with export const SampleServiceToken = new InjectionToken<string>('SampleService');

The only way it works is to provide the service in the main app @NgModule:

@NgModule({
    ...
    providers: [
        { provide: SampleService, useFactory: () => new SampleService(config) },
    ],
})

dependencies:

"@angular/common": "5.0.3",
"@angular/compiler": "5.0.3",
"@angular/compiler-cli": "5.0.3",
"@angular/core": "5.0.3",
"@angular/forms": "5.0.3",
"@angular/http": "5.0.3",
"@angular/platform-browser": "5.0.3",
"@angular/platform-browser-dynamic": "5.0.3",
"@ionic-native/core": "^4.4.0",
"@ionic-native/splash-screen": "4.4.0",
"@ionic-native/status-bar": "4.4.0",
"ionic-angular": "3.9.2",
"ionicons": "3.0.0",

来源：https://stackoverflow.com/questions/50881070/aot-ngmodule-provider-with-dependencies-nullinjectorerror