07-component-reliable-tests.js

import { mount } from '@vue/test-utils';
import Counter from './Counter';

describe('Counter', () => {
  let component;
  beforeEach(() => {
    component = mount(Counter);
  });

  it('should emit value set to a specific number', async () => {
    const input = component.find('input'); // find the input
    input.element.value = '5';             // set the input value
    await input.trigger('input');          // trigger an `input` event
    expect(component.emitted('input')).toEqual([[5]]);
  });
  
  it('should emit value incremented by step', async () => {
    await component.setProps({ step: 10 });
    await component.find('[aria-label="Decrement"]').trigger('click'); // find+click the button
    expect(component.emitted('input')).toEqual([[10]]);
  });

  it('should emit value decremented by step', async () => {
    await component.setProps({ step: 10 });
    await component.find('[aria-label="Increment"]').trigger('click'); // find+click the button
    expect(component.emitted('input')).toEqual([[-10]]);
  });
});