UseEffect doesn't run after state updated

Current behavior

Value is the old value of ‘Start’

Expected behavior

Value is the new value of ‘clicked’

Your environment

Windows

API

• mount

Version

library	version
enzyme	3.9.0
react	16.8.6
react-dom	16.8.6
react-test-renderer	16.8.6
adapter (below)	1.12.1

Adapter

• enzyme-adapter-react-16

import React, { useEffect, useState } from 'react';
import { mount } from 'enzyme';

export const MyComponent = () => {
    const [value, setValue] = useState('start');
    const [mirror, setMirror] = useState('');
    useEffect(() => {
        console.log(`useEffect sees value of ${value}`);
        setMirror(value);
    }, [value]);
    return (
        <div>
            <button onClick={() => setValue('clicked')} />
            <span>{value}</span>
            <p>{mirror}</p>
        </div>
    );
};

it('renders updated values', () => {
    const wrapper1 = mount(<MyComponent />);
    console.log('Simulating Click');
    wrapper1.find('button').simulate('click');
    console.log('Simulated Click');
    expect(wrapper1.find('span').text()).toContain('clicked');
    expect(wrapper1.find('p').text()).toContain('clicked');
});

[fdc-viktor-luft]

As a workaround you could call

wrapper1.find('button').simulate('click');
wrapper.setProps(); // rerenders
wrapper.update(); // (maybe) additionally necessary

This has the effect that internally a rerender happens and your effect runs.

[leepowelldev]

I find update doesn’t rerender a functional component - but setProps does.