Make remaining Utilities modules Flow strict-local (#57739)

Summary:
Pull Request resolved: #57739

Upgrade `deepDiffer`, `codegenNativeCommands`, `Dimensions`, and `ReactNativeTestTools` from `flow` to `flow strict-local`, preserving both public type signatures and runtime behavior. These modules operate on values of arbitrary shape, so the unavoidable `any` and `Function` usages are marked with scoped `$FlowFixMe[unclear-type]` rather than tightened.

`Dimensions.addEventListener` deliberately keeps its original `handler: Function` signature. Flow types object properties invariantly, so any precise payload annotation would reject existing subscribers that annotate the payload with their own object shapes, forcing unrelated call sites to change. The generated API snapshot is therefore unchanged for `Dimensions`.

Changelog: [Internal]

Reviewed By: javache

Differential Revision: D113763789

Author: rubennorte

packages/react-native/Libraries/Utilities/Dimensions.js

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -111,6 +111,8 @@ class Dimensions {
    */
   static addEventListener(
     type: 'change',
+    /* $FlowFixMe[unclear-type] Callers annotate the payload with assorted
+     * object shapes that any precise signature would reject. */
     handler: Function,
   ): EventSubscription {
     invariant(

packages/react-native/Libraries/Utilities/ReactNativeTestTools.js

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -163,7 +163,9 @@ function maximumDepthOfJSON(node: ?ReactTestRendererJSON): number {
   }
 }
 
-function renderAndEnforceStrictMode(element: React.Node): any {
+function renderAndEnforceStrictMode(
+  element: React.Node,
+): ReactTestRendererType {
   expectNoConsoleError();
   return renderWithStrictMode(element);
 }
@@ -217,7 +219,8 @@ function scrollToBottom(instance: ReactTestInstance) {
 // To make error messages a little bit better, we attach a custom toString
 // implementation to a predicate
 function withMessage(fn: Predicate, message: string): Predicate {
-  (fn as any).toString = () => message;
+  // $FlowFixMe[cannot-write] Deliberately overriding toString on the predicate.
+  fn.toString = () => message;
   return fn;
 }
 

packages/react-native/Libraries/Utilities/codegenNativeCommands.js

@@ -4,30 +4,40 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
+import type {HostInstance} from '../../src/private/types/HostInstance';
+
 const {dispatchCommand} = require('../ReactNative/RendererProxy');
 
 type NativeCommandsOptions<T = string> = Readonly<{
   supportedCommands: ReadonlyArray<T>,
 }>;
 
+declare function castCommandObject<T extends interface {}>(commandObj: {
+  [keyof T]: (...ReadonlyArray<unknown>) => void,
+}): T;
+function castCommandObject(commandObj: interface {}) {
+  return commandObj;
+}
+
 function codegenNativeCommands<T extends interface {}>(
-  options: NativeCommandsOptions<keyof T>,
+  options: NativeCommandsOptions<keyof T & string>,
 ): T {
   const commandObj: {[keyof T]: (...ReadonlyArray<unknown>) => void} = {};
 
   options.supportedCommands.forEach(command => {
-    // $FlowFixMe[missing-local-annot]
-    commandObj[command] = (ref, ...args) => {
-      // $FlowFixMe[incompatible-type]
+    commandObj[command] = (
+      ref: HostInstance,
+      ...args: Array<unknown>
+    ): void => {
       dispatchCommand(ref, command, args);
     };
   });
 
-  return commandObj as any as T;
+  return castCommandObject(commandObj);
 }
 
 export default codegenNativeCommands;

packages/react-native/Libraries/Utilities/differ/__tests__/deepDiffer-itest.js

@@ -136,7 +136,7 @@ describe('deepDiffer', function () {
     expect(
       deepDiffer(
         () => {},
-        x => x,
+        (x: unknown) => x,
       ),
     ).toBe(false);
     const f = () => {};
@@ -146,7 +146,7 @@ describe('deepDiffer', function () {
     expect(
       deepDiffer(
         () => {},
-        x => x,
+        (x: unknown) => x,
         undefined,
         {unsafelyIgnoreFunctions: false},
       ),
@@ -160,7 +160,7 @@ describe('deepDiffer', function () {
     expect(
       deepDiffer(
         () => {},
-        x => x,
+        (x: unknown) => x,
         {unsafelyIgnoreFunctions: false},
       ),
     ).toBe(true);

packages/react-native/Libraries/Utilities/differ/deepDiffer.js

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -29,8 +29,8 @@ function unstable_setLogListeners(listeners: ?LogListeners) {
  * @returns {bool} true if different, false if equal
  */
 function deepDiffer(
-  one: any,
-  two: any,
+  one: unknown,
+  two: unknown,
   maxDepthOrOptions: Options | number = -1,
   maybeOptions?: Options,
 ): boolean {
@@ -73,7 +73,9 @@ function deepDiffer(
     return true;
   }
   if (Array.isArray(one)) {
-    // We know two is also an array because the constructors are equal
+    if (!Array.isArray(two)) {
+      return true;
+    }
     const len = one.length;
     if (two.length !== len) {
       return true;

packages/react-native/Libraries/Utilities/useWindowDimensions.js

@@ -27,9 +27,10 @@ export default function useWindowDimensions():
   useEffect(() => {
     function handleChange({
       window,
-    }: {
+    }: Readonly<{
       window: DisplayMetrics | DisplayMetricsAndroid,
-    }) {
+      ...
+    }>) {
       if (
         dimensions.width !== window.width ||
         dimensions.height !== window.height ||

packages/react-native/ReactNativeApi.d.ts

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<efd59db9214ec5f9de127d9b01190bc6>>
+ * @generated SignedSource<<05c2ae417d791bd248bc677e89f0f307>>
  *
  * This file was generated by scripts/js-api/build-types/index.js.
  */
@@ -1730,7 +1730,7 @@ declare class CellRenderMask {
 declare type Clipboard = typeof Clipboard
 declare type codegenNativeCommands = typeof codegenNativeCommands
 declare function codegenNativeCommands_default<T extends {}>(
-  options: NativeCommandsOptions<keyof T>,
+  options: NativeCommandsOptions<keyof T & string>,
 ): T
 declare type codegenNativeComponent = typeof codegenNativeComponent
 declare function codegenNativeComponent_default<Props extends {}>(
@@ -6051,7 +6051,7 @@ export {
   VirtualizedSectionListInstance, // 12b706d5
   VirtualizedSectionListProps, // 52c34787
   WrapperComponentProvider, // 9b4247f6
-  codegenNativeCommands, // 628a7c0a
+  codegenNativeCommands, // 322f3f4e
   codegenNativeComponent, // 520daa94
   findNodeHandle, // 93f80214
   processColor, // 6e877698

packages/rn-tester/js/examples/Dimensions/DimensionsExample.js

@@ -15,7 +15,7 @@ import * as React from 'react';
 import {useEffect, useState} from 'react';
 import {Button, Dimensions, View, useWindowDimensions} from 'react-native';
 
-type Props = {dim: string};
+type Props = {dim: 'screen' | 'window'};
 
 function DimensionsSubscription(props: Props) {
   const [dims, setDims] = useState(() => Dimensions.get(props.dim));