fix: fix render hook typing (#1811)

Author: mdjastrzebski

.github/actions/setup-deps-react-18/action.yml

@@ -0,0 +1,32 @@
+name: Setup deps (React 18)
+description: Setup Node.js and install dependencies
+
+runs:
+  using: composite
+  steps:
+    - name: Setup Node.js
+      uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4.4.0
+      with:
+        node-version-file: .nvmrc
+
+    - name: Cache deps
+      id: yarn-cache
+      uses: actions/cache@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
+      with:
+        path: |
+          ./node_modules
+          .yarn/install-state.gz
+        key: ${{ runner.os }}-yarn-${{ hashFiles('yarn.lock') }}-${{ hashFiles('**/package.json', '!node_modules/**') }}
+        restore-keys: |
+          ${{ runner.os }}-yarn-${{ hashFiles('yarn.lock') }}
+          ${{ runner.os }}-yarn-
+
+    - name: Install deps
+      if: steps.yarn-cache.outputs.cache-hit != 'true'
+      run: yarn install --immutable
+      shell: bash
+
+    - name: Switch to React 18
+      run: |
+        yarn add -D react@18.3.1 react-test-renderer@18.3.1 @types/react@18.3.1 @types/react-test-renderer@18.3.1 react-native@0.77.0 @react-native/babel-preset@0.77.0
+      shell: bash

.github/workflows/ci.yml

@@ -40,6 +40,19 @@ jobs:
       - name: Typecheck
         run: yarn typecheck
 
+  typecheck-react-18:
+    runs-on: ubuntu-latest
+    name: Typecheck React 18
+    steps:
+      - name: Checkout
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+
+      - name: Setup Node.js and deps
+        uses: ./.github/actions/setup-deps-react-18
+
+      - name: Typecheck
+        run: yarn typecheck
+
   test:
     runs-on: ubuntu-latest
     name: Test
@@ -66,12 +79,7 @@ jobs:
         uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
 
       - name: Setup Node.js and deps
-        uses: ./.github/actions/setup-deps
-
-      - name: Switch to React 18
-        run: |
-          yarn remove react react-test-renderer react-native @react-native/babel-preset
-          yarn add -D react@18.3.1 react-test-renderer@18.3.1 react-native@0.77.0 @react-native/babel-preset@0.77.0
+        uses: ./.github/actions/setup-deps-react-18
 
       - name: Test
         run: yarn test:ci

src/__tests__/render-hook-async.test.tsx

@@ -13,6 +13,12 @@ afterEach(() => {
   console.error = originalConsoleError;
 });
 
+function useSuspendingHook(promise: Promise<string>) {
+  // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+  // @ts-ignore: React 18 does not have `use` hook
+  return React.use(promise);
+}
+
 test('renderHookAsync renders hook asynchronously', async () => {
   const { result } = await renderHookAsync(() => {
     const [state, setState] = React.useState(1);
@@ -124,10 +130,6 @@ test('handles multiple state updates in effects', async () => {
 });
 
 testGateReact19('handles hook with suspense', async () => {
-  function useSuspendingHook(promise: Promise<string>) {
-    return React.use(promise);
-  }
-
   let resolvePromise: (value: string) => void;
   const promise = new Promise<string>((resolve) => {
     resolvePromise = resolve;
@@ -169,10 +171,6 @@ testGateReact19('handles hook suspense with error boundary', async () => {
   // eslint-disable-next-line no-console
   console.error = excludeConsoleMessage(console.error, ERROR_MESSAGE);
 
-  function useSuspendingHook(promise: Promise<string>) {
-    return React.use(promise);
-  }
-
   let rejectPromise: (error: Error) => void;
   const promise = new Promise<string>((_resolve, reject) => {
     rejectPromise = reject;

src/__tests__/render-hook.test.tsx

@@ -60,32 +60,29 @@ test('allows wrapper components', () => {
   expect(result.current).toEqual('provided');
 });
 
-const useMyHook = (param: number | undefined) => {
-  return param;
-};
+function useMyHook<T>(param: T) {
+  return { param };
+}
 
 test('props type is inferred correctly when initial props is defined', () => {
-  const { result, rerender } = renderHook((num: number | undefined) => useMyHook(num), {
+  const { result, rerender } = renderHook((num: number) => useMyHook(num), {
     initialProps: 5,
   });
-
-  expect(result.current).toBe(5);
+  expect(result.current.param).toBe(5);
 
   rerender(6);
-
-  expect(result.current).toBe(6);
+  expect(result.current.param).toBe(6);
 });
 
 test('props type is inferred correctly when initial props is explicitly undefined', () => {
   const { result, rerender } = renderHook((num: number | undefined) => useMyHook(num), {
     initialProps: undefined,
   });
 
-  expect(result.current).toBeUndefined();
+  expect(result.current.param).toBeUndefined();
 
   rerender(6);
-
-  expect(result.current).toBe(6);
+  expect(result.current.param).toBe(6);
 });
 
 /**

src/__tests__/suspense-fake-timers.test.tsx

@@ -16,6 +16,8 @@ afterEach(() => {
 });
 
 function Suspending({ promise, testID }: { promise: Promise<unknown>; testID: string }) {
+  // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+  // @ts-ignore React 18 does not have `use` hook
   React.use(promise);
   return <View testID={testID} />;
 }

src/__tests__/suspense.test.tsx

@@ -14,6 +14,8 @@ afterEach(() => {
 });
 
 function Suspending({ promise, testID }: { promise: Promise<unknown>; testID: string }) {
+  // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+  // @ts-ignore React 18 does not have `use` hook
   React.use(promise);
   return <View testID={testID} />;
 }

src/render-hook.tsx

@@ -2,15 +2,16 @@ import * as React from 'react';
 
 import render from './render';
 import renderAsync from './render-async';
+import type { RefObject } from './types';
 
 export type RenderHookResult<Result, Props> = {
-  result: React.RefObject<Result>;
+  result: RefObject<Result>;
   rerender: (props: Props) => void;
   unmount: () => void;
 };
 
 export type RenderHookAsyncResult<Result, Props> = {
-  result: React.RefObject<Result>;
+  result: RefObject<Result>;
   rerenderAsync: (props: Props) => Promise<void>;
   unmountAsync: () => Promise<void>;
 };
@@ -39,7 +40,7 @@ export function renderHook<Result, Props>(
   hookToRender: (props: Props) => Result,
   options?: RenderHookOptions<Props>,
 ): RenderHookResult<Result, Props> {
-  const result: React.RefObject<Result | null> = React.createRef();
+  const result = React.createRef<Result>() as RefObject<Result>;
 
   function HookContainer({ hookProps }: { hookProps: Props }) {
     const renderResult = hookToRender(hookProps);
@@ -58,8 +59,7 @@ export function renderHook<Result, Props>(
   );
 
   return {
-    // Result should already be set after the first render effects are run.
-    result: result as React.RefObject<Result>,
+    result: result,
     rerender: (hookProps: Props) => rerenderComponent(<HookContainer hookProps={hookProps} />),
     unmount,
   };
@@ -69,7 +69,7 @@ export async function renderHookAsync<Result, Props>(
   hookToRender: (props: Props) => Result,
   options?: RenderHookOptions<Props>,
 ): Promise<RenderHookAsyncResult<Result, Props>> {
-  const result: React.RefObject<Result | null> = React.createRef();
+  const result = React.createRef<Result>() as RefObject<Result>;
 
   function TestComponent({ hookProps }: { hookProps: Props }) {
     const renderResult = hookToRender(hookProps);
@@ -88,8 +88,7 @@ export async function renderHookAsync<Result, Props>(
   );
 
   return {
-    // Result should already be set after the first render effects are run.
-    result: result as React.RefObject<Result>,
+    result: result,
     rerenderAsync: (hookProps: Props) =>
       rerenderComponentAsync(<TestComponent hookProps={hookProps} />),
     unmountAsync,

src/types.ts

@@ -1,3 +1,8 @@
+/** `RefObject` type from React 19. */
+export type RefObject<T> = {
+  current: T;
+};
+
 /**
  * Location of an element.
  */