Algo deu errado.

O login não funcionou, ele não foi para a outra página.

import { Component, OnInit } from '@angular/core';
import { FormBuilder, FormGroup, Validators } from '@angular/forms';
import { Router } from '@angular/router';
import { AuthService } from 'src/app/core/auth.service';

@Component({
    templateUrl: './signin.component.html'
})
export class SignInComponent implements OnInit{ 

    loginForm:FormGroup;

    constructor( 
        private formBuilder: FormBuilder,
        private authService: AuthService,
        private router:Router) {}

    ngOnInit(): void {
        this.loginForm = this.formBuilder.group({
            userName: ['', Validators.required],
            password: ['', Validators.required]
        });
    }

    login() {

        const userName = this.loginForm.get('userName').value;
        const password = this.loginForm.get('password').value;

        this.authService
            .authenticate(userName, password)
            .subscribe(
                () => this.router.navigate(['user', userName]),
                err => {
                    console.log(err);
                    this.loginForm.reset();
                }
            );
    }
}