From 16ca3afb1d221e6c576774d17499da5f48389dde Mon Sep 17 00:00:00 2001
From: W3D <koliakolmikov@gmail.com>
Date: Sat, 4 Apr 2026 22:47:28 +0200
Subject: [PATCH] [GENERAL][FIXED] - Fix WHATWG spec violations in URL and
 URLSearchParams polyfills

Summary:
Three spec violations in the URL/URLSearchParams polyfills:

1. URLSearchParams.size returned the number of unique keys (Map.size)
   instead of the total number of name-value pairs per the WHATWG spec.

2. URLSearchParams string constructor split on every '=' character,
   dropping parts of values that contain '='. Only the first '='
   should be treated as a key-value separator.

3. URL.hash getter used a regex that stopped at '/', breaking
   fragment identifiers like #/users/123 common in SPA routing.
---
 packages/react-native/Libraries/Blob/URL.js        |  4 ++--
 .../react-native/Libraries/Blob/URLSearchParams.js | 14 ++++++++++----
 .../Libraries/Blob/__tests__/URL-test.js           |  2 +-
 3 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/packages/react-native/Libraries/Blob/URL.js b/packages/react-native/Libraries/Blob/URL.js
index f4f879a51214..f65b3762796b 100644
--- a/packages/react-native/Libraries/Blob/URL.js
+++ b/packages/react-native/Libraries/Blob/URL.js
@@ -123,8 +123,8 @@ export class URL {
   }
 
   get hash(): string {
-    const hashMatch = this._url.match(/#([^/]*)/);
-    return hashMatch ? `#${hashMatch[1]}` : '';
+    const hashIndex = this._url.indexOf('#');
+    return hashIndex !== -1 ? this._url.slice(hashIndex) : '';
   }
 
   get host(): string {
diff --git a/packages/react-native/Libraries/Blob/URLSearchParams.js b/packages/react-native/Libraries/Blob/URLSearchParams.js
index d325f7bb25a8..c3570513b2cd 100644
--- a/packages/react-native/Libraries/Blob/URLSearchParams.js
+++ b/packages/react-native/Libraries/Blob/URLSearchParams.js
@@ -14,7 +14,11 @@ export class URLSearchParams {
   _searchParams: Map<string, string[]> = new Map();
 
   get size(): number {
-    return this._searchParams.size;
+    let count = 0;
+    for (const values of this._searchParams.values()) {
+      count += values.length;
+    }
+    return count;
   }
 
   constructor(params?: Record<string, string> | string | [string, string][]) {
@@ -33,9 +37,11 @@ export class URLSearchParams {
           if (!pair) {
             return;
           }
-          const [key, value] = pair
-            .split('=')
-            .map(part => decodeURIComponent(part.replace(/\+/g, ' ')));
+          const eqIndex = pair.indexOf('=');
+          const rawKey = eqIndex === -1 ? pair : pair.slice(0, eqIndex);
+          const rawValue = eqIndex === -1 ? '' : pair.slice(eqIndex + 1);
+          const key = decodeURIComponent(rawKey.replace(/\+/g, ' '));
+          const value = decodeURIComponent(rawValue.replace(/\+/g, ' '));
           this.append(key, value);
         });
     } else if (Array.isArray(params)) {
diff --git a/packages/react-native/Libraries/Blob/__tests__/URL-test.js b/packages/react-native/Libraries/Blob/__tests__/URL-test.js
index 72467dc08ebb..86ae866482be 100644
--- a/packages/react-native/Libraries/Blob/__tests__/URL-test.js
+++ b/packages/react-native/Libraries/Blob/__tests__/URL-test.js
@@ -110,7 +110,7 @@ describe('URL', function () {
       ['key1', 'value2'],
       ['key2', 'value3'],
     ]);
-    expect(paramsFromArray.size).toBe(2);
+    expect(paramsFromArray.size).toBe(3);
     expect(paramsFromArray.getAll('key1')).toEqual(['value1', 'value2']);
     expect(paramsFromArray.get('key2')).toBe('value3');