switch useRenderGuard to an approach not accessing React's internals

.changeset/brown-bikes-divide.md

@@ -0,0 +1,5 @@
+---
+"@apollo/client": patch
+---
+
+switch `useRenderGuard` to an approach not accessing React's internals

.size-limits.json

@@ -1,4 +1,4 @@
 {
-  "dist/apollo-client.min.cjs": 39620,
+  "dist/apollo-client.min.cjs": 39561,
   "import { ApolloClient, InMemoryCache, HttpLink } from \"dist/index.js\" (production)": 32821
 }

src/react/hooks/internal/__tests__/useRenderGuard.test.tsx

@@ -2,7 +2,6 @@
 import React, { useEffect } from "rehackt";
 import { useRenderGuard } from "../useRenderGuard";
 import { render, waitFor } from "@testing-library/react";
-import { withCleanup } from "../../../../testing/internal";
 
 const UNDEF = {};
 const IS_REACT_19 = React.version.startsWith("19");
@@ -35,45 +34,3 @@ it("returns a function that returns `false` if called after render", async () =>
   });
   expect(result).toBe(false);
 });
-
-function breakReactInternalsTemporarily() {
-  const R = React as unknown as {
-    __SECRET_INTERNALS_DO_NOT_USE_OR_YOU_WILL_BE_FIRED: any;
-  };
-  const orig = R.__SECRET_INTERNALS_DO_NOT_USE_OR_YOU_WILL_BE_FIRED;
-
-  R.__SECRET_INTERNALS_DO_NOT_USE_OR_YOU_WILL_BE_FIRED = {};
-  return withCleanup({}, () => {
-    R.__SECRET_INTERNALS_DO_NOT_USE_OR_YOU_WILL_BE_FIRED = orig;
-  });
-}
-
-it("results in false negatives if React internals change", () => {
-  let result: boolean | typeof UNDEF = UNDEF;
-  function TestComponent() {
-    using _ = breakReactInternalsTemporarily();
-    const calledDuringRender = useRenderGuard();
-    result = calledDuringRender();
-    return <>Test</>;
-  }
-  render(<TestComponent />);
-  expect(result).toBe(false);
-});
-
-it("does not result in false positives if React internals change", async () => {
-  let result: boolean | typeof UNDEF = UNDEF;
-  function TestComponent() {
-    using _ = breakReactInternalsTemporarily();
-    const calledDuringRender = useRenderGuard();
-    useEffect(() => {
-      using _ = breakReactInternalsTemporarily();
-      result = calledDuringRender();
-    });
-    return <>Test</>;
-  }
-  render(<TestComponent />);
-  await waitFor(() => {
-    expect(result).not.toBe(UNDEF);
-  });
-  expect(result).toBe(false);
-});

src/react/hooks/internal/useRenderGuard.ts

@@ -1,23 +1,45 @@
 import * as React from "rehackt";
 
-function getRenderDispatcher() {
-  return (React as any).__SECRET_INTERNALS_DO_NOT_USE_OR_YOU_WILL_BE_FIRED
-    ?.ReactCurrentDispatcher?.current;
-}
-
-let RenderDispatcher: unknown = null;
+let Ctx: React.Context<null>;
 
-/*
-Relay does this too, so we hope this is safe.
-https://github.com/facebook/relay/blob/8651fbca19adbfbb79af7a3bc40834d105fd7747/packages/react-relay/relay-hooks/loadQuery.js#L90-L98
-*/
+function noop() {}
 export function useRenderGuard() {
-  // eslint-disable-next-line react-compiler/react-compiler
-  RenderDispatcher = getRenderDispatcher();
+  if (!Ctx) {
+    // we want the intialization to be lazy because `createContext` would error on import in a RSC
+    Ctx = React.createContext(null);
+  }
+
+  return React.useCallback(
+    /**
+     * @returns true if the hook was called during render
+     */ () => {
+      const orig = console.error;
+      try {
+        console.error = noop;
 
-  return React.useCallback(() => {
-    return (
-      RenderDispatcher != null && RenderDispatcher === getRenderDispatcher()
-    );
-  }, []);
+        /**
+         * `useContext` can be called conditionally during render, so this is safe.
+         * (Also, during render we would want to throw as a reaction to this anyways, so it
+         * wouldn't even matter if we got the order of hooks mixed up...)
+         *
+         * They cannot however be called outside of Render, and that's what we're testing here.
+         *
+         * Different versions of React have different behaviour on an invalid hook call:
+         *
+         * React 16.8 - 17: throws an error
+         * https://github.com/facebook/react/blob/2b93d686e359c7afa299e2ec5cf63160a32a1155/packages/react/src/ReactHooks.js#L18-L26
+         *
+         * React 18 & 19: `console.error` in development, then `resolveDispatcher` returns `null` and a member access on `null` throws.
+         * https://github.com/facebook/react/blob/58e8304483ebfadd02a295339b5e9a989ac98c6e/packages/react/src/ReactHooks.js#L28-L35
+         */
+        React["useContext" /* hide this from the linter */](Ctx);
+        return true;
+      } catch (e) {
+        return false;
+      } finally {
+        console.error = orig;
+      }
+    },
+    []
+  );
 }