Button click test - ts

app.component.ts

import { Component } from '@angular/core';
import { TestService } from './test-service/test.service';
import { Router } from '@angular/router';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent {
  title = 'button-click-test';
  errorMessage = '';
  successMessage = '';

  constructor(private router: Router, private testService: TestService) { }

  clickAction() {
    this.testService.callAPI().subscribe(
      (response) => {
        this.successMessage = response.body.message;
        this.router.navigate(['/teste']);
      },
      errorResponse => {
        this.errorMessage = errorResponse.message;
      }
    );
  }
}