Angular: Can`t resolve all parameters for Component

Question

I have downloaded a simple Angular app from this demo. After using npm i and ng serve I keep getting this message. Been trying to fix it, figured i will get some help here, since i have not found any solution elsewhere. Same thing happens to every other component.

introduction.component.ts

import { Component } from '@angular/core';
import { Router } from '@angular/router';


@Component({
  selector: 'codelab-quiz-intro',
  templateUrl: './introduction.component.html',
  styleUrls: ['./introduction.component.scss']
})
export class IntroductionComponent {

  constructor(private router: Router) {}

  startQuiz() {
    this.router.navigateByUrl('/question/1');
  }
}
  

app.module.ts

import { NgModule, NO_ERRORS_SCHEMA, CUSTOM_ELEMENTS_SCHEMA } from '@angular/core';
// import { CommonModule } from "@angular/common";
import {BrowserAnimationsModule} from "@angular/platform-browser/animations";
import {BrowserModule} from "@angular/platform-browser";
import { ReactiveFormsModule } from '@angular/forms';
import { MatCardModule } from '@angular/material/card';
import { MatRadioModule, MAT_RADIO_DEFAULT_OPTIONS } from '@angular/material/radio';
import { MatIconModule } from '@angular/material/icon';
import { MatButtonModule } from '@angular/material/button';
import { NgbModule } from '@ng-bootstrap/ng-bootstrap';
import { AccordionModule } from 'ngx-bootstrap/accordion';
import { Route, Router, RouterModule } from '@angular/router';
import { AppRoutingModule } from './app-routing.module';
import { AppComponent } from './app.component';
import { IntroductionComponent } from './containers/introduction/introduction.component';
import { QuestionComponent } from './containers/question/question.component';
import * as QuestionComponent2 from './components/question/question.component';
import { ResultsComponent } from './containers/results/results.component';

const routes: Route[] = [
  { path: 'intro', component: IntroductionComponent, pathMatch: 'full' },
  { path: 'question', component: QuestionComponent, pathMatch: 'full' },
  { path: 'question/:questionId', component: QuestionComponent, pathMatch: 'full' },
  { path: 'results', component: ResultsComponent, pathMatch: 'full' },
  { path: '', redirectTo: 'intro', pathMatch: 'full' }
];


@NgModule({
  declarations: [
    AppComponent,
    IntroductionComponent,
    QuestionComponent,
    QuestionComponent2.QuestionComponent,
    ResultsComponent,
  ],
  imports: [
    // CommonModule,
    BrowserModule,
    BrowserAnimationsModule,
    AppRoutingModule,
    ReactiveFormsModule,
    MatCardModule,
    MatRadioModule,
    MatIconModule,
    MatButtonModule,
    NgbModule,
    AccordionModule.forRoot()
  ],
  providers: [{
    provide: MAT_RADIO_DEFAULT_OPTIONS,
    useValue: { color: 'accent' },
  }],
  bootstrap: [ AppComponent ],
  schemas: [
    CUSTOM_ELEMENTS_SCHEMA,
    NO_ERRORS_SCHEMA
  ]
})
export class AppModule { }

app-routing.module.ts

import { NgModule } from '@angular/core';
import { Route, RouterModule } from '@angular/router';
import { IntroductionComponent } from './containers/introduction/introduction.component';
import { QuestionComponent } from './containers/question/question.component';
import { ResultsComponent } from './containers/results/results.component';

const routes: Route[] = [
  { path: 'intro', component: IntroductionComponent, pathMatch: 'full' },
  { path: 'question', component: QuestionComponent, pathMatch: 'full' },
  { path: 'question/:questionId', component: QuestionComponent, pathMatch: 'full' },
  { path: 'results', component: ResultsComponent, pathMatch: 'full' },
  { path: '', redirectTo: 'intro', pathMatch: 'full' }
];

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

Answer 1

Please add this config "emitDecoratorMetadata": true on tsconfig.spec.json file and it will work.

"compilerOptions": {
    "emitDecoratorMetadata": true,