[Flight] Add getCacheForType() to the dispatcher

fixtures/flight/server/cli.server.js

@@ -17,13 +17,28 @@ const app = express();
 // Application
 app.get('/', function(req, res) {
   if (process.env.NODE_ENV === 'development') {
-    for (var key in require.cache) {
-      delete require.cache[key];
-    }
+    // This doesn't work in ESM mode.
+    // for (var key in require.cache) {
+    //   delete require.cache[key];
+    // }
   }
   require('./handler.server.js')(req, res);
 });
 
+app.get('/todos', function(req, res) {
+  res.setHeader('Access-Control-Allow-Origin', '*');
+  res.json([
+    {
+      id: 1,
+      text: 'Shave yaks',
+    },
+    {
+      id: 2,
+      text: 'Eat kale',
+    },
+  ]);
+});
+
 app.listen(3001, () => {
   console.log('Flight Server listening on port 3001...');
 });

fixtures/flight/src/App.server.js

@@ -1,4 +1,5 @@
 import * as React from 'react';
+import {fetch} from 'react-fetch';
 
 import Container from './Container.js';
 
@@ -8,11 +9,17 @@ import {Counter as Counter2} from './Counter2.client.js';
 import ShowMore from './ShowMore.client.js';
 
 export default function App() {
+  const todos = fetch('http://localhost:3001/todos').json();
   return (
     <Container>
       <h1>Hello, world</h1>
       <Counter />
       <Counter2 />
+      <ul>
+        {todos.map(todo => (
+          <li key={todo.id}>{todo.text}</li>
+        ))}
+      </ul>
       <ShowMore>
         <p>Lorem ipsum</p>
       </ShowMore>

packages/react-debug-tools/src/ReactDebugHooks.js

@@ -13,6 +13,7 @@ import type {
   MutableSourceSubscribeFn,
   ReactContext,
   ReactProviderType,
+  ReactCache,
 } from 'shared/ReactTypes';
 import type {
   Fiber,
@@ -23,6 +24,7 @@ import type {OpaqueIDType} from 'react-reconciler/src/ReactFiberHostConfig';
 import {NoMode} from 'react-reconciler/src/ReactTypeOfMode';
 
 import ErrorStackParser from 'error-stack-parser';
+import invariant from 'shared/invariant';
 import ReactSharedInternals from 'shared/ReactSharedInternals';
 import {REACT_OPAQUE_ID_TYPE} from 'shared/ReactSymbols';
 import {
@@ -100,6 +102,10 @@ function nextHook(): null | Hook {
   return hook;
 }
 
+function readCache(): ReactCache {
+  invariant(false, 'Not implemented.');
+}
+
 function readContext<T>(
   context: ReactContext<T>,
   observedBits: void | number | boolean,
@@ -298,6 +304,7 @@ function useOpaqueIdentifier(): OpaqueIDType | void {
 }
 
 const Dispatcher: DispatcherType = {
+  readCache,
   readContext,
   useCallback,
   useContext,

packages/react-dom/src/server/ReactPartialRendererHooks.js

@@ -14,6 +14,7 @@ import type {
   MutableSourceGetSnapshotFn,
   MutableSourceSubscribeFn,
   ReactContext,
+  ReactCache,
 } from 'shared/ReactTypes';
 import type PartialRenderer from './ReactPartialRenderer';
 
@@ -214,6 +215,10 @@ export function resetHooksState(): void {
   workInProgressHook = null;
 }
 
+function readCache(): ReactCache {
+  invariant(false, 'Not implemented.');
+}
+
 function readContext<T>(
   context: ReactContext<T>,
   observedBits: void | number | boolean,
@@ -492,6 +497,7 @@ export function setCurrentPartialRenderer(renderer: PartialRenderer) {
 }
 
 export const Dispatcher: DispatcherType = {
+  readCache,
   readContext,
   useContext,
   useMemo,

packages/react-fetch/src/ReactFetchBrowser.js

@@ -7,9 +7,9 @@
  * @flow
  */
 
-import type {Wakeable} from 'shared/ReactTypes';
+import type {Wakeable, ReactCache} from 'shared/ReactTypes';
 
-import {readCache} from 'react/unstable-cache';
+import * as React from 'react';
 
 const Pending = 0;
 const Resolved = 1;
@@ -36,6 +36,14 @@ type Result = PendingResult | ResolvedResult | RejectedResult;
 const nativeFetch = window.fetch;
 const fetchKey = {};
 
+const ReactCurrentDispatcher =
+  React.__SECRET_INTERNALS_DO_NOT_USE_OR_YOU_WILL_BE_FIRED
+    .ReactCurrentDispatcher;
+
+function readCache(): ReactCache {
+  return ReactCurrentDispatcher.current.readCache();
+}
+
 function readResultMap(): Map<string, Result> {
   const resources = readCache().resources;
   let map = resources.get(fetchKey);

packages/react-fetch/src/ReactFetchNode.js

@@ -7,12 +7,11 @@
  * @flow
  */
 
-import type {Wakeable} from 'shared/ReactTypes';
+import type {Wakeable, ReactCache} from 'shared/ReactTypes';
 
 import * as http from 'http';
 import * as https from 'https';
-
-import {readCache} from 'react/unstable-cache';
+import * as React from 'react';
 
 type FetchResponse = {|
   // Properties
@@ -75,6 +74,14 @@ type RejectedResult = {|
 
 type Result<V> = PendingResult | ResolvedResult<V> | RejectedResult;
 
+const ReactCurrentDispatcher =
+  React.__SECRET_INTERNALS_DO_NOT_USE_OR_YOU_WILL_BE_FIRED
+    .ReactCurrentDispatcher;
+
+function readCache(): ReactCache {
+  return ReactCurrentDispatcher.current.readCache();
+}
+
 const fetchKey = {};
 
 function readResultMap(): Map<string, Result<FetchResponse>> {