[enzyme-adapter-react-16] [fix] mount: wrap simulate() in ReactTestUtils.act()

Wraps the mount simulate method in ReactTestUtils.act() to correctly allow component interactions to be tested in a synchronous way Fixes #2084

Author: petersendidit

packages/enzyme-adapter-react-16/src/ReactSixteenAdapter.js

@@ -474,7 +474,9 @@ class ReactSixteenAdapter extends EnzymeAdapter {
  if (!eventFn) {
  throw new TypeError(`ReactWrapper::simulate() event '${event}' does not exist`);
  }
- eventFn(adapter.nodeToHostNode(node), mock);
+ wrapAct(() => {
+ eventFn(adapter.nodeToHostNode(node), mock);
+ });
  },
  batchedUpdates(fn) {
  return fn();

packages/enzyme-test-suite/test/shared/methods/simulate.jsx

@@ -13,6 +13,8 @@ import {
 
 import {
  memo,
+ useEffect,
+ useState,
 } from '../../_helpers/react-compat';
 
 export default function describeSimulate({
@@ -316,5 +318,30 @@ export default function describeSimulate({
  expect(handleClick).to.have.property('callCount', 3);
  });
  });
+
+ describeIf(is('>= 16.8'), 'hooks', () => {
+ // TODO: fix for shallow when useEffect works for shallow
+ itIf(!isShallow, 'works with `useEffect` simulated events', () => {
+ const effectSpy = sinon.spy();
+ function ComponentUsingEffectHook() {
+ useEffect(effectSpy);
+ const [counter, setCounter] = useState(0);
+
+ return (
+ <button type="button" onClick={() => setCounter(counter + 1)}>{counter}</button>
+ );
+ }
+ const wrapper = Wrap(<ComponentUsingEffectHook />);
+
+ const button = wrapper.find('button');
+ expect(button.text()).to.equal('0');
+ expect(effectSpy).to.have.property('callCount', 1);
+
+ button.simulate('click');
+
+ expect(button.text()).to.equal('1');
+ expect(effectSpy).to.have.property('callCount', 2);
+ });
+ });
  });
 }