NullInjectorError: StaticInjectorError(DynamicTestModule)[ToastrService -> InjectionToken ToastConfig]: in tslint angular 8

import { ToastrModule } from 'ngx-toastr';

beforeEach(async(() => {
    TestBed.configureTestingModule({
      imports: [ToastrModule.forRoot()],

    })
      .compileComponents();
  }));

Add ToastrModule.forRoot() in imports as shown above and your error might be resolved

These approaches did not work for me. I had to provide my own value for the provider. This is what worked for me:

First, I declared my own "dummy" implementation:

const toastrService = {
    success: (message?: string, title?: string, override?: Partial<IndividualConfig>) => { },
    error: (message?: string, title?: string, override?: Partial<IndividualConfig>) => { }
  };

Then, I indicated the value to use in the providers section:

providers: [
        ...
        { provide: ToastrService, useValue: toastrService },
      ],