Adding Library configs using `forRoot()` and `InjectionToken` with angular5

Question

I'm writing an Angular library named where I need to pass in a configuration object in the.forRoot() of the module import.的 Angular 库，我需要在模块导入的 .forRoot() 中传入一个配置对象。

I'm trying to do this with InjectionToken, but when I run my application(installed build with ) with ng build--prod , I got an error just like this安装的构建）时，我收到了这样的错误

ERROR in Error during template compile of 'TestModule' Function calls are not supported in decorators but 'libModule' was called.

import { NgModule } from '@angular/core';
import { CONFIG, Config } from './config';
import { LibService } from './libService';

@NgModule({ ... })
export class LibModule {
    static forRoot(config?: any): ModuleWithProviders {
        return {
            ngModule: LibModule,
            providers: [
                LibService, 
                { provide: CONFIG, useValue: config }
            ]
        };
    }
}

import { InjectionToken } from '@angular/core';

export const CONFIG = new InjectionToken<Config>('config');

export interface Config {
    key?: string;
}

import { Observable } from "rxjs/Observable";
import { Injectable, Inject } from "@angular/core";
import { Config, LIB_CONFIG } from "./config";

@Injectable()
export class LibService {

  private key: string;

  constructor(
    @Inject(LIB_CONFIG) config: any
  ) { 
    this.key = config.KEY;
    console.log('ewrwerwerwrewrewr'+this.key);
  }
}

import { NgModule } from '@angular/core';
import { LibModule } from 'some-library';

@NgModule({
    imports: [
        libModule.forRoot({
            // <-- config values here
        })
    ]
})

Answer 1

For my case, I remove the debug statement before return of forRoot function.

Reference: https://github.com/angular/angular-cli/issues/9358#issuecomment-435288467