Use react@17 for useSyncExternalStore shim tests (#28055)

The tests for the shim need to test with ReactDOM.render in React 17.

packages/use-sync-external-store/package.json

@@ -20,5 +20,9 @@
   "license": "MIT",
   "peerDependencies": {
     "react": "^16.8.0 || ^17.0.0 || ^18.0.0"
+  },
+  "devDependencies": {
+    "react-17": "npm:react@^17",
+    "react-dom-17": "npm:react-dom@^17"
   }
 }

packages/use-sync-external-store/src/__tests__/useSyncExternalStoreShared-test.js

@@ -29,22 +29,21 @@ describe('Shared useSyncExternalStore behavior (shim and built-in)', () => {
     jest.resetModules();
 
     if (gate(flags => flags.enableUseSyncExternalStoreShim)) {
-      // Remove useSyncExternalStore from the React imports so that we use the
-      // shim instead. Also removing startTransition, since we use that to
-      // detect outdated 18 alphas that don't yet include useSyncExternalStore.
-      //
-      // Longer term, we'll probably test this branch using an actual build
-      // of React 17.
+      // Test the shim against React 17.
       jest.mock('react', () => {
-        const {
-          // eslint-disable-next-line no-unused-vars
-          startTransition: _,
-          // eslint-disable-next-line no-unused-vars
-          useSyncExternalStore: __,
-          ...otherExports
-        } = jest.requireActual('react');
-        return otherExports;
+        return jest.requireActual(
+          __DEV__
+            ? 'react-17/umd/react.development.js'
+            : 'react-17/umd/react.production.min.js',
+        );
       });
+      jest.mock('react-dom', () =>
+        jest.requireActual(
+          __DEV__
+            ? 'react-dom-17/umd/react-dom.development.js'
+            : 'react-dom-17/umd/react-dom.production.min.js',
+        ),
+      );
     }
 
     React = require('react');
@@ -100,6 +99,7 @@ describe('Shared useSyncExternalStore behavior (shim and built-in)', () => {
       // createLegacyRoot directly.
       return ReactDOMClient.createRoot(container);
     } else {
+      // This ReactDOM.render is from the React 17 npm module.
       ReactDOM.render(null, container);
       return {
         render(children) {
@@ -594,6 +594,15 @@ describe('Shared useSyncExternalStore behavior (shim and built-in)', () => {
       );
     }).toErrorDev(
       'The result of getSnapshot should be cached to avoid an infinite loop',
+      {
+        withoutStack: gate(flags => {
+          if (flags.enableUseSyncExternalStoreShim) {
+            // Stacks don't work when mixing the source and the npm package.
+            return flags.source;
+          }
+          return false;
+        }),
+      },
     );
   });
 

scripts/jest/setupTests.js

@@ -170,9 +170,14 @@ if (process.env.REACT_CLASS_EQUIVALENCE_TEST) {
         return message;
       }
       const re = /react.dev\/errors\/(\d+)?\??([^\s]*)/;
-      const matches = message.match(re);
+      let matches = message.match(re);
       if (!matches || matches.length !== 3) {
-        return message;
+        // Some tests use React 17, when the URL was different.
+        const re17 = /error-decoder.html\?invariant=(\d+)([^\s]*)/;
+        matches = message.match(re17);
+        if (!matches || matches.length !== 3) {
+          return message;
+        }
       }
       const code = parseInt(matches[1], 10);
       const args = matches[2]

yarn.lock

@@ -12838,6 +12838,14 @@ rc@^1.0.1, rc@^1.1.6, rc@^1.2.8:
     prop-types "^15.6.2"
     scheduler "^0.13.0"
 
+"react-17@npm:react@^17":
+  version "17.0.2"
+  resolved "https://registry.yarnpkg.com/react/-/react-17.0.2.tgz#d0b5cc516d29eb3eee383f75b62864cfb6800037"
+  integrity sha512-gnhPt75i/dq/z3/6q/0asP78D0u592D5L1pd7M8P+dck6Fu/jJeL6iVVK23fptSUZj8Vjf++7wXA8UNclGQcbA==
+  dependencies:
+    loose-envify "^1.1.0"
+    object-assign "^4.1.1"
+
 "react-dom-15@npm:react-dom@^15":
   version "15.6.2"
   resolved "https://registry.yarnpkg.com/react-dom/-/react-dom-15.6.2.tgz#41cfadf693b757faf2708443a1d1fd5a02bef730"
@@ -12858,6 +12866,15 @@ rc@^1.0.1, rc@^1.1.6, rc@^1.2.8:
     prop-types "^15.6.2"
     scheduler "^0.13.0"
 
+"react-dom-17@npm:react-dom@^17":
+  version "17.0.2"
+  resolved "https://registry.yarnpkg.com/react-dom/-/react-dom-17.0.2.tgz#ecffb6845e3ad8dbfcdc498f0d0a939736502c23"
+  integrity sha512-s4h96KtLDUQlsENhMn1ar8t2bEa+q/YAtj8pPPdIjPDGBDIVNsrD9aXNWqspUe6AzKCIG0C1HZZLqLV7qpOBGA==
+  dependencies:
+    loose-envify "^1.1.0"
+    object-assign "^4.1.1"
+    scheduler "^0.20.2"
+
 react-is@^16.8.1, react-is@^17.0.1, "react-is@npm:react-is":
   version "17.0.2"
   resolved "https://registry.yarnpkg.com/react-is/-/react-is-17.0.2.tgz#e691d4a8e9c789365655539ab372762b0efb54f0"
@@ -13524,6 +13541,14 @@ scheduler@^0.13.0:
     loose-envify "^1.1.0"
     object-assign "^4.1.1"
 
+scheduler@^0.20.2:
+  version "0.20.2"
+  resolved "https://registry.yarnpkg.com/scheduler/-/scheduler-0.20.2.tgz#4baee39436e34aa93b4874bddcbf0fe8b8b50e91"
+  integrity sha512-2eWfGgAqqWFGqtdMmcL5zCMK1U8KlXv8SQFGglL3CEtd0aDVDWgeF/YoCmvln55m5zSk3J/20hTaSBeSObsQDQ==
+  dependencies:
+    loose-envify "^1.1.0"
+    object-assign "^4.1.1"
+
 schema-utils@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/schema-utils/-/schema-utils-1.0.0.tgz#0b79a93204d7b600d4b2850d1f66c2a34951c770"