Add test cases for setState(fn) + render phase updates

packages/react-reconciler/src/__tests__/ReactHooks-test.internal.js

@@ -669,6 +669,76 @@ describe('ReactHooks', () => {
  }).toThrow('is not a function');
  });
 
+ it('does not forget render phase useState updates inside an effect', () => {
+ const {useState, useEffect} = React;
+
+ function Counter() {
+ const [counter, setCounter] = useState(0);
+ if (counter === 0) {
+ setCounter(x => x + 1);
+ setCounter(x => x + 1);
+ }
+ useEffect(() => {
+ setCounter(x => x + 1);
+ setCounter(x => x + 1);
+ }, []);
+ return counter;
+ }
+
+ const root = ReactTestRenderer.create(null);
+ ReactTestRenderer.act(() => {
+ root.update(<Counter />);
+ });
+ expect(root).toMatchRenderedOutput('4');
+ });
+
+ it('does not forget render phase useReducer updates inside an effect with hoisted reducer', () => {
+ const {useReducer, useEffect} = React;
+
+ const reducer = x => x + 1;
+ function Counter() {
+ const [counter, increment] = useReducer(reducer, 0);
+ if (counter === 0) {
+ increment();
+ increment();
+ }
+ useEffect(() => {
+ increment();
+ increment();
+ }, []);
+ return counter;
+ }
+
+ const root = ReactTestRenderer.create(null);
+ ReactTestRenderer.act(() => {
+ root.update(<Counter />);
+ });
+ expect(root).toMatchRenderedOutput('4');
+ });
+
+ it('does not forget render phase useReducer updates inside an effect with inline reducer', () => {
+ const {useReducer, useEffect} = React;
+
+ function Counter() {
+ const [counter, increment] = useReducer(x => x + 1, 0);
+ if (counter === 0) {
+ increment();
+ increment();
+ }
+ useEffect(() => {
+ increment();
+ increment();
+ }, []);
+ return counter;
+ }
+
+ const root = ReactTestRenderer.create(null);
+ ReactTestRenderer.act(() => {
+ root.update(<Counter />);
+ });
+ expect(root).toMatchRenderedOutput('4');
+ });
+
  it('warns for bad useImperativeHandle first arg', () => {
  const {useImperativeHandle} = React;
  function App() {