The simulate method is Error!

[zenjava]

link : http://airbnb.io/enzyme/docs/api/ReactWrapper/simulate.html
``

class Foo extends React.Component {
  constructor(props) {
    super(props);
    this.state = { count: 0 };
  }
  render() {
    const { count } = this.state;
    return (
      <div>
        <div className={`clicks-${count}`}>
          {count} clicks
        </div>
        <a href="url" onClick={() => { this.setState({ count: count + 1 }); }}>
          Increment
        </a>
      </div>
    );
  }
}

const wrapper = mount(<Foo />);

expect(wrapper.find('.clicks-0').length).to.equal(1); 
wrapper.find('a').simulate('click');
expect(wrapper.find('.clicks-1').length).to.equal(1) // expected 0 to euqal 1 <===== the error

``

[ljharb]

What version of enzyme and react are you using?

What if you wrapper.update() after the simulate?

[zenjava]

import React from 'react';
import enzyme, { mount, shallow, } from 'enzyme';
import { expect, } from 'chai';
import Adapter from 'enzyme-adapter-react-16';

enzyme.configure({ adapter: new Adapter(), });


describe('Test', () => {
  it('simulate', () => {
    class Foo extends React.Component {
      constructor (props) {
        super(props);
        this.state = { count: 0, };
      }

      render () {
        const { count, } = this.state;
        return (
          <div>
            <div className={`clicks-${count}`}>
              {count} clicks
            </div>
            <a href="url" onClick={() => {
              this.setState({ count: count + 1, });
            }}>
              Increment
            </a>
          </div>
        );
      }
    }

    const wrapper = mount(<Foo/>);

    expect(wrapper.find('.clicks-0').length).to.equal(1);
    wrapper.find('a').simulate('click');
    wrapper.update();
    expect(wrapper.find('.clicks-1').length).to.equal(1); //<==== is error
  });

});

"react": "16.0.0",
"react-dev-utils": "3.0.2",
"react-dom": "16.0.0",
"react-error-overlay": "1.0.9",

"enzyme": "3.1.1",
"enzyme-adapter-react-16": "1.0.0",

[ljharb]

hmm; this might be a duplicate of #1229; does #1229 (comment) help?

[zenjava]

I am update enzyme-adapter-react-16 to 1.1.0. Run result is OK.I think that is enzyme bug,but fix 1.1.0.

[zenjava]

I see the code, The following code fixes to change the problem.
1.1.0 : const node = findCurrentFiberUsingSlowPath(vnode); --fixed
1.0.0 : const node = vnode.alternate !== null ? vnode.alternate : vnode;

[ljharb]

Sounds like v1.1.0 fixed it.