Try assigning fetch to globalThis if global assignment fails

In case it's a more modern yet rigid environment.

.eslintrc.js

@@ -277,5 +277,6 @@ module.exports = {
     trustedTypes: 'readonly',
     IS_REACT_ACT_ENVIRONMENT: 'readonly',
     AsyncLocalStorage: 'readonly',
+    globalThis: 'readonly',
   },
 };

packages/react/src/ReactFetch.js

@@ -42,92 +42,98 @@ function generateCacheKey(request: Request): string {
 if (enableCache && enableFetchInstrumentation) {
   if (typeof fetch === 'function') {
     const originalFetch = fetch;
-    try {
-      // eslint-disable-next-line no-native-reassign
-      fetch = function fetch(
-        resource: URL | RequestInfo,
-        options?: RequestOptions,
+    const cachedFetch = function fetch(
+      resource: URL | RequestInfo,
+      options?: RequestOptions,
+    ) {
+      const dispatcher = ReactCurrentCache.current;
+      if (!dispatcher) {
+        // We're outside a cached scope.
+        return originalFetch(resource, options);
+      }
+      if (
+        options &&
+        options.signal &&
+        options.signal !== dispatcher.getCacheSignal()
       ) {
-        const dispatcher = ReactCurrentCache.current;
-        if (!dispatcher) {
-          // We're outside a cached scope.
-          return originalFetch(resource, options);
-        }
+        // If we're passed a signal that is not ours, then we assume that
+        // someone else controls the lifetime of this object and opts out of
+        // caching. It's effectively the opt-out mechanism.
+        // Ideally we should be able to check this on the Request but
+        // it always gets initialized with its own signal so we don't
+        // know if it's supposed to override - unless we also override the
+        // Request constructor.
+        return originalFetch(resource, options);
+      }
+      // Normalize the Request
+      let url: string;
+      let cacheKey: string;
+      if (typeof resource === 'string' && !options) {
+        // Fast path.
+        cacheKey = simpleCacheKey;
+        url = resource;
+      } else {
+        // Normalize the request.
+        const request = new Request(resource, options);
         if (
-          options &&
-          options.signal &&
-          options.signal !== dispatcher.getCacheSignal()
+          (request.method !== 'GET' && request.method !== 'HEAD') ||
+          // $FlowFixMe: keepalive is real
+          request.keepalive
         ) {
-          // If we're passed a signal that is not ours, then we assume that
-          // someone else controls the lifetime of this object and opts out of
-          // caching. It's effectively the opt-out mechanism.
-          // Ideally we should be able to check this on the Request but
-          // it always gets initialized with its own signal so we don't
-          // know if it's supposed to override - unless we also override the
-          // Request constructor.
+          // We currently don't dedupe requests that might have side-effects. Those
+          // have to be explicitly cached. We assume that the request doesn't have a
+          // body if it's GET or HEAD.
+          // keepalive gets treated the same as if you passed a custom cache signal.
           return originalFetch(resource, options);
         }
-        // Normalize the Request
-        let url: string;
-        let cacheKey: string;
-        if (typeof resource === 'string' && !options) {
-          // Fast path.
-          cacheKey = simpleCacheKey;
-          url = resource;
-        } else {
-          // Normalize the request.
-          const request = new Request(resource, options);
-          if (
-            (request.method !== 'GET' && request.method !== 'HEAD') ||
-            // $FlowFixMe: keepalive is real
-            request.keepalive
-          ) {
-            // We currently don't dedupe requests that might have side-effects. Those
-            // have to be explicitly cached. We assume that the request doesn't have a
-            // body if it's GET or HEAD.
-            // keepalive gets treated the same as if you passed a custom cache signal.
-            return originalFetch(resource, options);
+        cacheKey = generateCacheKey(request);
+        url = request.url;
+      }
+      const cache = dispatcher.getCacheForType(createFetchCache);
+      const cacheEntries = cache.get(url);
+      let match;
+      if (cacheEntries === undefined) {
+        // We pass the original arguments here in case normalizing the Request
+        // doesn't include all the options in this environment.
+        match = originalFetch(resource, options);
+        cache.set(url, [cacheKey, match]);
+      } else {
+        // We use an array as the inner data structure since it's lighter and
+        // we typically only expect to see one or two entries here.
+        for (let i = 0, l = cacheEntries.length; i < l; i += 2) {
+          const key = cacheEntries[i];
+          const value = cacheEntries[i + 1];
+          if (key === cacheKey) {
+            match = value;
+            // I would've preferred a labelled break but lint says no.
+            return match.then(response => response.clone());
           }
-          cacheKey = generateCacheKey(request);
-          url = request.url;
         }
-        const cache = dispatcher.getCacheForType(createFetchCache);
-        const cacheEntries = cache.get(url);
-        let match;
-        if (cacheEntries === undefined) {
-          // We pass the original arguments here in case normalizing the Request
-          // doesn't include all the options in this environment.
-          match = originalFetch(resource, options);
-          cache.set(url, [cacheKey, match]);
-        } else {
-          // We use an array as the inner data structure since it's lighter and
-          // we typically only expect to see one or two entries here.
-          for (let i = 0, l = cacheEntries.length; i < l; i += 2) {
-            const key = cacheEntries[i];
-            const value = cacheEntries[i + 1];
-            if (key === cacheKey) {
-              match = value;
-              // I would've preferred a labelled break but lint says no.
-              return match.then(response => response.clone());
-            }
-          }
-          match = originalFetch(resource, options);
-          cacheEntries.push(cacheKey, match);
-        }
-        // We clone the response so that each time you call this you get a new read
-        // of the body so that it can be read multiple times.
-        return match.then(response => response.clone());
-      };
-      // We don't expect to see any extra properties on fetch but if there are any,
-      // copy them over. Useful for extended fetch environments or mocks.
-      Object.assign(fetch, originalFetch);
-    } catch (error) {
-      // Log even in production just to make sure this is seen if only prod is frozen.
-      // eslint-disable-next-line react-internal/no-production-logging
-      console.warn(
-        'React was unable to patch the fetch() function in this environment. ' +
-          'Suspensey APIs might not work correctly as a result.',
-      );
+        match = originalFetch(resource, options);
+        cacheEntries.push(cacheKey, match);
+      }
+      // We clone the response so that each time you call this you get a new read
+      // of the body so that it can be read multiple times.
+      return match.then(response => response.clone());
+    };
+    // We don't expect to see any extra properties on fetch but if there are any,
+    // copy them over. Useful for extended fetch environments or mocks.
+    Object.assign(cachedFetch, originalFetch);
+    try {
+      // eslint-disable-next-line no-native-reassign
+      fetch = cachedFetch;
+    } catch (error1) {
+      try {
+        // In case assigning it globally fails, try globalThis instead just in case it exists.
+        globalThis.fetch = cachedFetch;
+      } catch (error2) {
+        // Log even in production just to make sure this is seen if only prod is frozen.
+        // eslint-disable-next-line react-internal/no-production-logging
+        console.warn(
+          'React was unable to patch the fetch() function in this environment. ' +
+            'Suspensey APIs might not work correctly as a result.',
+        );
+      }
     }
   }
 }

scripts/flow/environment.js

@@ -18,6 +18,8 @@ declare var __REACT_DEVTOOLS_GLOBAL_HOOK__: any; /*?{
   inject: ?((stuff: Object) => void)
 };*/
 
+declare var globalThis: Object;
+
 declare var queueMicrotask: (fn: Function) => void;
 declare var reportError: (error: mixed) => void;
 

scripts/rollup/validate/eslintrc.cjs2015.js

@@ -16,6 +16,7 @@ module.exports = {
     WeakSet: 'readonly',
     Uint16Array: 'readonly',
     Reflect: 'readonly',
+    globalThis: 'readonly',
     // Vendor specific
     MSApp: 'readonly',
     __REACT_DEVTOOLS_GLOBAL_HOOK__: 'readonly',

scripts/rollup/validate/eslintrc.esm.js

@@ -15,6 +15,7 @@ module.exports = {
     WeakSet: 'readonly',
     Uint16Array: 'readonly',
     Reflect: 'readonly',
+    globalThis: 'readonly',
     // Vendor specific
     MSApp: 'readonly',
     __REACT_DEVTOOLS_GLOBAL_HOOK__: 'readonly',

scripts/rollup/validate/eslintrc.fb.js

@@ -15,6 +15,7 @@ module.exports = {
     WeakSet: 'readonly',
     Uint16Array: 'readonly',
     Reflect: 'readonly',
+    globalThis: 'readonly',
     // Vendor specific
     MSApp: 'readonly',
     __REACT_DEVTOOLS_GLOBAL_HOOK__: 'readonly',

scripts/rollup/validate/eslintrc.rn.js

@@ -14,6 +14,7 @@ module.exports = {
     WeakMap: 'readonly',
     WeakSet: 'readonly',
     Reflect: 'readonly',
+    globalThis: 'readonly',
     // Vendor specific
     MSApp: 'readonly',
     __REACT_DEVTOOLS_GLOBAL_HOOK__: 'readonly',

scripts/rollup/validate/eslintrc.umd.js

@@ -14,6 +14,7 @@ module.exports = {
     WeakSet: 'readonly',
     Uint16Array: 'readonly',
     Reflect: 'readonly',
+    globalThis: 'readonly',
     // Vendor specific
     MSApp: 'readonly',
     __REACT_DEVTOOLS_GLOBAL_HOOK__: 'readonly',
@@ -24,7 +25,6 @@ module.exports = {
     module: 'readonly',
     define: 'readonly',
     require: 'readonly',
-    globalThis: 'readonly',
     global: 'readonly',
     // Internet Explorer
     setImmediate: 'readonly',