NG10/NG7 unit testing component unit test example

src_tests_test.component.spec.ts

import { Component } from '@angular/core';
import { TestBed } from '@angular/core/testing';
import { customNsTestBedAfterEach, customNsTestBedBeforeEach } from './setup';
@Component({
  selector: 'test-comp',
  template: '' // template is blank, because code does not have NO_ERRORS_SCHEMA and also we don't care. only testing functions in component 
})
class TestComponent{

  hello(): string { return 'hello'; }
}

let component: TestComponent;
describe('Test Component', () => {
  beforeEach(customNsTestBedBeforeEach(
    [],
    [ TestComponent ],
    []
  ));

  afterEach(() => customNsTestBedAfterEach());

  describe('Function Tests -', () => { 
    beforeEach(() => {
      component = TestBed.inject(TestComponent);
    });
    
    describe('hello()', () => {
      it('should say "hello"', () => {
          expect(component.hello()).toEqual('hello');
      });
    });
  });
});