Shallow test renderer calls shouldComponentUpdate on forceUpdate

[d4rky-pl]

There is no extra guard or clause in enqueueForceUpdate when calling render which means the render always calls shouldComponentUpdate which can block even forced re-render during tests.

This for example breaks shallow rendering in Enzyme when using MobX and observables.

Minimal test case:

import React from 'react'
import ShallowRenderer from 'react-test-renderer/shallow';
const renderer = new ShallowRenderer();

class TestComponent extends React.Component {
  render() { return <span/> }
}

describe('forceUpdate', () => {
  it('does not call shouldComponentUpdate', () => {
    let called = 0
    TestComponent.prototype.shouldComponentUpdate = () => called += 1
    const component = renderer.render(<TestComponent/>);
    renderer._instance.forceUpdate()
    expect(called).toBe(0) // <- this throws because called === 1
  })
})

[gaearon]

React 16.1.0-beta has been released. Please update react, react-dom, and react-test-renderer (if you use it) to this version and let us know if it solved the issue! We’d appreciate if you could test before Monday when we plan to get 16.1.0 out.

[d4rky-pl]

@gaearon Hey, it seems that I actually botched this fix - the shouldComponentUpdate() is no longer called but the component is still not rerendered properly (check was done in wrong if clause). I've sent another PR that resolves this, please check #11439.

Apologies for extra noise!