react · rubennorte · Jul 29, 2026 · Jul 29, 2026 · Jul 29, 2026
diff --git a/packages/react-native/Libraries/Blob/File.js b/packages/react-native/Libraries/Blob/File.js
@@ -4,10 +4,12 @@
  * 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
  */
 
+// flowlint unsafe-getters-setters:off
+
 'use strict';
 
 import type {BlobOptions} from './BlobTypes';

diff --git a/packages/react-native/Libraries/Blob/FileReader.js b/packages/react-native/Libraries/Blob/FileReader.js
@@ -4,10 +4,12 @@
  * 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
  */
 
+// flowlint unsafe-getters-setters:off
+
 import type {EventCallback} from '../../src/private/webapis/dom/events/EventTarget';
 import type Blob from './Blob';
 

diff --git a/packages/react-native/Libraries/Blob/URL.js b/packages/react-native/Libraries/Blob/URL.js
@@ -4,10 +4,12 @@
  * 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
  */
 
+// flowlint unsafe-getters-setters:off
+
 import type Blob from './Blob';
 
 import NativeBlobModule from './NativeBlobModule';
@@ -79,6 +81,7 @@ export class URL {
   // $FlowFixMe[missing-local-annot]
   constructor(url: string, base?: string | URL) {
     let baseUrl = null;
+    // $FlowFixMe[sketchy-null-string]
     if (!base || validateBaseUrl(url)) {
       this._url = url;
       if (this._url.includes('#')) {
@@ -112,13 +115,14 @@ export class URL {
       if (baseUrl.endsWith('/')) {
         baseUrl = baseUrl.slice(0, baseUrl.length - 1);
       }
-      if (!url.startsWith('/')) {
-        url = `/${url}`;
+      let path = url;
+      if (!path.startsWith('/')) {
+        path = `/${path}`;
       }
-      if (baseUrl.endsWith(url)) {
-        url = '';
+      if (baseUrl.endsWith(path)) {
+        path = '';
       }
-      this._url = `${baseUrl}${url}`;
+      this._url = `${baseUrl}${path}`;
     }
   }
 

diff --git a/packages/react-native/Libraries/Blob/URLSearchParams.js b/packages/react-native/Libraries/Blob/URLSearchParams.js
@@ -4,10 +4,12 @@
  * 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
  */
 
+// flowlint unsafe-getters-setters:off
+
 // Small subset from whatwg-url: https://github.com/jsdom/whatwg-url/tree/master/src
 // The reference code bloat comes from Unicode issues with URLs, so those won't work here.
 export class URLSearchParams {

diff --git a/packages/react-native/Libraries/Blob/URLSearchParams.js.flow b/packages/react-native/Libraries/Blob/URLSearchParams.js.flow
@@ -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
  */
 

diff --git a/packages/react-native/Libraries/StyleSheet/StyleSheet.js b/packages/react-native/Libraries/StyleSheet/StyleSheet.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
  */
 

diff --git a/packages/react-native/Libraries/StyleSheet/StyleSheet.js.flow b/packages/react-native/Libraries/StyleSheet/StyleSheet.js.flow
@@ -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
  */
 

diff --git a/packages/react-native/Libraries/StyleSheet/StyleSheetExports.js.flow b/packages/react-native/Libraries/StyleSheet/StyleSheetExports.js.flow
@@ -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
  */
 
@@ -86,9 +86,9 @@ declare export const flatten: typeof flattenStyle;
  * internally to process color and transform values. You should not use this
  * unless you really know what you are doing and have exhausted other options.
  */
-declare export const setStyleAttributePreprocessor: (
+declare export const setStyleAttributePreprocessor: <T>(
   property: string,
-  process: (nextProp: any) => any,
+  process: (nextProp: T) => unknown,
 ) => void;
 
 /**

diff --git a/packages/react-native/Libraries/StyleSheet/processFilter.js b/packages/react-native/Libraries/StyleSheet/processFilter.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 strict-local
  */
 
@@ -51,13 +51,13 @@ export default function processFilter(
   }
 
   if (typeof filter === 'string') {
-    filter = filter.replace(NEWLINE_REGEX, ' ');
+    const normalizedFilter = filter.replace(NEWLINE_REGEX, ' ');
 
     // matches on functions with args and nested functions like "drop-shadow(10 10 10 rgba(0, 0, 0, 1))"
     FILTER_FUNCTION_REGEX.lastIndex = 0;
     let matches;
 
-    while ((matches = FILTER_FUNCTION_REGEX.exec(filter))) {
+    while ((matches = FILTER_FUNCTION_REGEX.exec(normalizedFilter))) {
       let filterName = matches[1].toLowerCase();
       if (filterName === 'drop-shadow') {
         const dropShadow = parseDropShadow(matches[2]);
@@ -159,7 +159,7 @@ function _getFilterAmount(filterName: string, filterArgs: unknown): ?number {
     // blur takes any positive CSS length that is not a percent. In RN
     // we currently only have DIPs, so we are not parsing units here.
     case 'blur':
-      if ((unit && unit !== 'px') || filterArgAsNumber < 0) {
+      if ((Boolean(unit) && unit !== 'px') || filterArgAsNumber < 0) {
         return undefined;
       }
       return filterArgAsNumber;
@@ -173,7 +173,10 @@ function _getFilterAmount(filterName: string, filterArgs: unknown): ?number {
     case 'opacity':
     case 'saturate':
     case 'sepia':
-      if ((unit && unit !== '%' && unit !== 'px') || filterArgAsNumber < 0) {
+      if (
+        (Boolean(unit) && unit !== '%' && unit !== 'px') ||
+        filterArgAsNumber < 0
+      ) {
         return undefined;
       }
       if (unit === '%') {

diff --git a/packages/react-native/Libraries/StyleSheet/processTransformOrigin.js b/packages/react-native/Libraries/StyleSheet/processTransformOrigin.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
  */
 
@@ -20,10 +20,11 @@ const INDEX_Z = 2;
 
 /* eslint-disable no-labels */
 export default function processTransformOrigin(
-  transformOrigin: Array<string | number> | string,
+  transformOriginInput: Array<string | number> | string,
 ): Array<string | number> {
-  if (typeof transformOrigin === 'string') {
-    const transformOriginString = transformOrigin;
+  let transformOrigin: Array<string | number>;
+  if (typeof transformOriginInput === 'string') {
+    const transformOriginString = transformOriginInput;
     TRANSFORM_ORIGIN_REGEX.lastIndex = 0;
     const transformOriginArray: Array<string | number> = ['50%', '50%', 0];
 
@@ -111,6 +112,8 @@ export default function processTransformOrigin(
     }
 
     transformOrigin = transformOriginArray;
+  } else {
+    transformOrigin = transformOriginInput;
   }
 
   if (__DEV__) {

diff --git a/packages/react-native/Libraries/StyleSheet/setNormalizedColorAlpha.js b/packages/react-native/Libraries/StyleSheet/setNormalizedColorAlpha.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
  */
 
@@ -17,15 +17,16 @@
  * alpha should be number between 0 and 1
  */
 function setNormalizedColorAlpha(input: number, alpha: number): number {
-  if (alpha < 0) {
-    alpha = 0;
-  } else if (alpha > 1) {
-    alpha = 1;
+  let normalizedAlpha = alpha;
+  if (normalizedAlpha < 0) {
+    normalizedAlpha = 0;
+  } else if (normalizedAlpha > 1) {
+    normalizedAlpha = 1;
   }
 
-  alpha = Math.round(alpha * 255);
+  normalizedAlpha = Math.round(normalizedAlpha * 255);
   // magic bitshift guarantees we return an unsigned int
-  return ((input & 0xffffff00) | alpha) >>> 0;
+  return ((input & 0xffffff00) | normalizedAlpha) >>> 0;
 }
 
 export default setNormalizedColorAlpha;
diff --git a/packages/react-native/ReactNativeApi.d.ts b/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<<d895833bed3d3c274a6647773deaa023>>
+ * @generated SignedSource<<9e84d3a75a150cc9d571738d15f28d91>>
  *
  * This file was generated by scripts/js-api/build-types/index.js.
  */
@@ -371,9 +371,9 @@ declare const sequence: typeof $$AnimatedImplementation.sequence
 declare const sequenceImpl: (
   animations: Array<CompositeAnimation>,
 ) => CompositeAnimation
-declare const setStyleAttributePreprocessor: (
+declare const setStyleAttributePreprocessor: <T>(
   property: string,
-  process: (nextProp: any) => any,
+  process: (nextProp: T) => unknown,
 ) => void
 declare const Settings: typeof Settings_default
 declare let Settings_default: {
@@ -5937,7 +5937,7 @@ export {
   StatusBarProps, // c2a44d88
   StatusBarStyle, // 78f53eea
   StyleProp, // fa0e9b4a
-  StyleSheet, // e734acd4
+  StyleSheet, // 94c9aa8e
   SubmitBehavior, // c4ddf490
   Switch, // f495bab3
   SwitchChangeEvent, // 899635b1

diff --git a/packages/react-native/src/private/specs_DEPRECATED/modules/NativeAccessibilityManager.js b/packages/react-native/src/private/specs_DEPRECATED/modules/NativeAccessibilityManager.js
@@ -4,46 +4,47 @@
  * 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 {TurboModule} from '../../../../Libraries/TurboModule/RCTExport';
+import type {UnsafeObject} from '../../../../Libraries/Types/CodegenTypes';
 
 import * as TurboModuleRegistry from '../../../../Libraries/TurboModule/TurboModuleRegistry';
 
 export interface Spec extends TurboModule {
   readonly getCurrentBoldTextState: (
     onSuccess: (isBoldTextEnabled: boolean) => void,
-    onError: (error: Object) => void,
+    onError: (error: UnsafeObject) => void,
   ) => void;
   readonly getCurrentGrayscaleState: (
     onSuccess: (isGrayscaleEnabled: boolean) => void,
-    onError: (error: Object) => void,
+    onError: (error: UnsafeObject) => void,
   ) => void;
   readonly getCurrentInvertColorsState: (
     onSuccess: (isInvertColorsEnabled: boolean) => void,
-    onError: (error: Object) => void,
+    onError: (error: UnsafeObject) => void,
   ) => void;
   readonly getCurrentReduceMotionState: (
     onSuccess: (isReduceMotionEnabled: boolean) => void,
-    onError: (error: Object) => void,
+    onError: (error: UnsafeObject) => void,
   ) => void;
   readonly getCurrentDarkerSystemColorsState?: (
     onSuccess: (isDarkerSystemColorsEnabled: boolean) => void,
-    onError: (error: Object) => void,
+    onError: (error: UnsafeObject) => void,
   ) => void;
   readonly getCurrentPrefersCrossFadeTransitionsState?: (
     onSuccess: (prefersCrossFadeTransitions: boolean) => void,
-    onError: (error: Object) => void,
+    onError: (error: UnsafeObject) => void,
   ) => void;
   readonly getCurrentReduceTransparencyState: (
     onSuccess: (isReduceTransparencyEnabled: boolean) => void,
-    onError: (error: Object) => void,
+    onError: (error: UnsafeObject) => void,
   ) => void;
   readonly getCurrentVoiceOverState: (
     onSuccess: (isScreenReaderEnabled: boolean) => void,
-    onError: (error: Object) => void,
+    onError: (error: UnsafeObject) => void,
   ) => void;
   readonly setAccessibilityContentSizeMultipliers: (JSMultipliers: {
     readonly extraSmall?: ?number,

diff --git a/packages/react-native/src/private/specs_DEPRECATED/modules/NativeActionSheetManager.js b/packages/react-native/src/private/specs_DEPRECATED/modules/NativeActionSheetManager.js
@@ -4,11 +4,12 @@
  * 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 {TurboModule} from '../../../../Libraries/TurboModule/RCTExport';
+import type {UnsafeObject} from '../../../../Libraries/Types/CodegenTypes';
 
 import * as TurboModuleRegistry from '../../../../Libraries/TurboModule/TurboModuleRegistry';
 
@@ -45,7 +46,7 @@ export interface Spec extends TurboModule {
     failureCallback: (error: {
       readonly domain: string,
       readonly code: string,
-      readonly userInfo?: ?Object,
+      readonly userInfo?: ?UnsafeObject,
       readonly message: string,
     }) => void,
     successCallback: (completed: boolean, activityType: ?string) => void,

diff --git a/packages/react-native/src/private/specs_DEPRECATED/modules/NativeAlertManager.js b/packages/react-native/src/private/specs_DEPRECATED/modules/NativeAlertManager.js
@@ -4,18 +4,19 @@
  * 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 {TurboModule} from '../../../../Libraries/TurboModule/RCTExport';
+import type {UnsafeObject} from '../../../../Libraries/Types/CodegenTypes';
 
 import * as TurboModuleRegistry from '../../../../Libraries/TurboModule/TurboModuleRegistry';
 
 export type Args = {
   title?: string,
   message?: string,
-  buttons?: Array<Object>, // TODO(T67565166): have a better type
+  buttons?: Array<UnsafeObject>, // TODO(T67565166): have a better type
   type?: string,
   defaultValue?: string,
   cancelButtonKey?: string,