ASSERTION ERROR: Type passed in is not ComponentType, it does not have 'ɵcmp' property

Question

I get this error whenever the app is running, though is not causing me problems in current development (i think) I would like to understand this error and know where it comes, because I'm completely lost, I can't even post relevant code. But i'll try..

So these are the main routes (appModule):

const routes: Routes = [
  {path:'home', component:HomeComponent, canActivate:[AuthGuardService]},
  {path:'detail/:id', component:DetailComponent},
  {path: 'register', component: RegisterComponent},
  {path:'login', component: LoginComponent},
  {path:'', redirectTo:'login', pathMatch: 'full'},
  {path:'**',  redirectTo:'login'}

];

@NgModule({
  imports: [RouterModule.forRoot(routes)],
  exports: [RouterModule]
})
export class AppRoutingModule { }

I have a core module where all the components are registed, and i'm importing the RouterModule.forChild([]) :

@NgModule({
  declarations: [HomeComponent, DetailComponent, RegisterComponent, LoginComponent],
  imports: [
    CommonModule,
    FormsModule,
    ReactiveFormsModule,
    RouterModule.forChild([])
  ]
})
export class CoreModule { }

The package.json:

{
  "name": "mat-shop",
  "version": "0.0.0",
  "scripts": {
    "ng": "ng",
    "start": "ng serve",
    "build": "ng build",
    "test": "ng test",
    "lint": "ng lint",
    "e2e": "ng e2e"
  },
  "private": true,
  "dependencies": {
    "@angular/animations": "~9.1.9",
    "@angular/cdk": "^9.2.4",
    "@angular/common": "~9.1.9",
    "@angular/compiler": "~9.1.9",
    "@angular/core": "~9.1.9",
    "@angular/forms": "~9.1.9",
    "@angular/localize": "~9.1.9",
    "@angular/material": "^9.2.4",
    "@angular/platform-browser": "~9.1.9",
    "@angular/platform-browser-dynamic": "~9.1.9",
    "@angular/router": "~9.1.9",
    "@ng-bootstrap/ng-bootstrap": "^6.1.0",
    "bootstrap": "^4.4.0",
    "rxjs": "~6.5.4",
    "tslib": "^1.10.0",
    "zone.js": "~0.10.2"
  },
  "devDependencies": {
    "@angular-devkit/build-angular": "~0.901.7",
    "@angular/cli": "~9.1.7",
    "@angular/compiler-cli": "~9.1.9",
    "@types/node": "^12.11.1",
    "@types/jasmine": "~3.5.0",
    "@types/jasminewd2": "~2.0.3",
    "codelyzer": "^5.1.2",
    "jasmine-core": "~3.5.0",
    "jasmine-spec-reporter": "~4.2.1",
    "karma": "~5.0.0",
    "karma-chrome-launcher": "~3.1.0",
    "karma-coverage-istanbul-reporter": "~2.1.0",
    "karma-jasmine": "~3.0.1",
    "karma-jasmine-html-reporter": "^1.4.2",
    "protractor": "~7.0.0",
    "ts-node": "~8.3.0",
    "tslint": "~6.1.0",
    "typescript": "~3.8.3"
  }
}

EDIT appModule

@NgModule({
  declarations: [
    AppComponent,
  ],
  imports: [
    BrowserModule,
    HttpClientModule,
    BrowserAnimationsModule,
    CoreModule,
    NgbModule

  ],
  providers: [DataService, fakeBackendProvider, AuthService, AuthGuardService, ShoppingCartService ],
  bootstrap: [AppComponent, HttpClient]

I never seen this error.Is it an Angular 9 issue? Am I doing something wrong?

Answer 1

This error may come due to two common mistakes

When you load module instead of component or vice versa then this error comes.

1. Loading Module instead of Component ie

{
   path: 'login',
   component: LoginModule // mistake
}

2. Loading Component instead of Module ie

{
   path: 'login',
   loadChildren: () => import('./login.module').then(m => m.LoginComponent) // mistake
}

Answer 2

You have HttpClient in bootstrap array of your appmodule. That's why it is giving this error.

Answer 3

I had the same error, happened when I did use the matDialog.open() method which need to have a component and not a module .

be sure to import the component you're using

1. the.module file into the main.module.ts

import { YourModalModule } from './your-modal.module.ts'// <-- .module.ts
//...
@NgModule({
imports: [
  YourModalModule
]
})

2. the.component file into the main.component.ts

import { YourModalModule } from './your-modal.component.ts' // <-- .component.ts
//...
const confirmDialogRef = this._matDialog.open(YourModuleComponent, {})
// ...

Edit
Also got the same error while working in a library .

the path to the import was pointing to the .umd which isn't correct

import { YourModuleComponent } from 'dist/website/bundles/my-lib.umd' // <-- mistake

const routes: Routes = [{ path: '', component: YourModuleComponent }]

import { YourModuleComponent } from './your-module.component' // <-- correct

const routes: Routes = [{ path: '', component: YourModuleComponent }]

Answer 4

I got this error when I accidently deleted the @ character from the @Component decorator in a page's Typescript file. For example:

@Component({
    selector: 'app-reset-password',
    templateUrl: './reset-password.page.html',
    styleUrls: ['./reset-password.page.scss'],
})
export class ResetPasswordPage {}

Answer 5

You will also get this error when you are opening matDialog and you pass any different type other than a component .

I passed directive instead of the component to dialog.open method.

this.dialog.open(
  MyDirective, //Make sure this is component
  {...}
);

Answer 6

I just had the same issue, but nothing was wrong with my module or component files and their imports. I just deleted the.angular folder and ran yarn run build again and everything worked perfectly.