Add stable React.act export (#28160)

Starting in version 19, users can import the `act` testing API from the
`react` package instead of using a renderer specific API, like
`react-dom/test-utils`.

Author: acdlite

fixtures/dom/src/__tests__/nested-act-test.js

@@ -20,7 +20,7 @@ describe('unmocked scheduler', () => {
   beforeEach(() => {
     jest.resetModules();
     React = require('react');
-    DOMAct = React.unstable_act;
+    DOMAct = React.act;
     TestRenderer = require('react-test-renderer');
     TestAct = TestRenderer.act;
   });
@@ -61,7 +61,7 @@ describe('mocked scheduler', () => {
       require.requireActual('scheduler/unstable_mock')
     );
     React = require('react');
-    DOMAct = React.unstable_act;
+    DOMAct = React.act;
     TestRenderer = require('react-test-renderer');
     TestAct = TestRenderer.act;
   });

packages/react-devtools-shared/src/__tests__/storeComponentFilters-test.js

@@ -19,7 +19,9 @@ describe('Store component filters', () => {
   let utils;
 
   const act = async (callback: Function) => {
-    if (React.unstable_act != null) {
+    if (React.act != null) {
+      await React.act(callback);
+    } else if (React.unstable_act != null) {
       await React.unstable_act(callback);
     } else {
       callback();

packages/react-devtools-shared/src/__tests__/utils.js

@@ -21,7 +21,9 @@ export function act(
   const {act: actTestRenderer} = require('react-test-renderer');
   // Use `require('react-dom/test-utils').act` as a fallback for React 17, which can be used in integration tests for React DevTools.
   const actDOM =
-    require('react').unstable_act || require('react-dom/test-utils').act;
+    require('react').act ||
+    require('react').unstable_act ||
+    require('react-dom/test-utils').act;
 
   actDOM(() => {
     actTestRenderer(() => {

packages/react-dom/src/__tests__/ReactDOMHydrationDiff-test.js

@@ -25,7 +25,7 @@ describe('ReactDOMServerHydration', () => {
     React = require('react');
     ReactDOMClient = require('react-dom/client');
     ReactDOMServer = require('react-dom/server');
-    act = React.unstable_act;
+    act = React.act;
 
     console.error = jest.fn();
     container = document.createElement('div');

packages/react-dom/src/__tests__/ReactTestUtilsActUnmockedScheduler-test.js

@@ -32,7 +32,7 @@ beforeEach(() => {
   yields = [];
   React = require('react');
   ReactDOMClient = require('react-dom/client');
-  act = React.unstable_act;
+  act = React.act;
   container = document.createElement('div');
   document.body.appendChild(container);
 });

packages/react-dom/src/test-utils/ReactTestUtils.js

@@ -39,7 +39,9 @@ const getFiberCurrentPropsFromNode = EventInternals[2];
 const enqueueStateRestore = EventInternals[3];
 const restoreStateIfNeeded = EventInternals[4];
 
-const act = React.unstable_act;
+// TODO: Add a warning if this API is accessed with advice to switch to
+// importing directly from the React package instead.
+const act = React.act;
 
 function Event(suffix) {}
 

packages/react-reconciler/src/__tests__/ReactActWarnings-test.js

@@ -28,7 +28,7 @@ describe('act warnings', () => {
     React = require('react');
     Scheduler = require('scheduler');
     ReactNoop = require('react-noop-renderer');
-    act = React.unstable_act;
+    act = React.act;
     useState = React.useState;
     Suspense = React.Suspense;
     startTransition = React.startTransition;

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

@@ -20,7 +20,7 @@ describe('ReactFiberHostContext', () => {
   beforeEach(() => {
     jest.resetModules();
     React = require('react');
-    act = React.unstable_act;
+    act = React.act;
     ReactFiberReconciler = require('react-reconciler');
     ConcurrentRoot =
       require('react-reconciler/src/ReactRootTags').ConcurrentRoot;

packages/react-reconciler/src/__tests__/ReactIsomorphicAct-test.js

@@ -28,7 +28,7 @@ describe('isomorphic act()', () => {
     ReactNoop = require('react-noop-renderer');
     DiscreteEventPriority =
       require('react-reconciler/constants').DiscreteEventPriority;
-    act = React.unstable_act;
+    act = React.act;
     use = React.use;
     Suspense = React.Suspense;
     startTransition = React.startTransition;

packages/react-reconciler/src/__tests__/ReactSchedulerIntegration-test.js

@@ -370,7 +370,7 @@ describe('`act` bypasses Scheduler methods completely,', () => {
     }
 
     const root = ReactNoop.createRoot();
-    const publicAct = React.unstable_act;
+    const publicAct = React.act;
     const prevIsReactActEnvironment = global.IS_REACT_ACT_ENVIRONMENT;
     try {
       global.IS_REACT_ACT_ENVIRONMENT = true;