From c85c5b5ee6c031d78dee314f6a47de8ab037a9d0 Mon Sep 17 00:00:00 2001
From: Oskar Eichler <oskar@songstats.com>
Date: Mon, 31 Aug 2026 02:48:30 +0300
Subject: [PATCH 1/2] Preserve nested Platform write targets

---
 .../__tests__/inline-platform-plugin-test.js  | 18 ++++++++++
 .../src/inline-platform-plugin.js             | 34 ++++++++++++++-----
 2 files changed, 43 insertions(+), 9 deletions(-)

diff --git a/packages/react-native-babel-preset/src/__tests__/inline-platform-plugin-test.js b/packages/react-native-babel-preset/src/__tests__/inline-platform-plugin-test.js
index 92bb4aac073..8632b1a7141 100644
--- a/packages/react-native-babel-preset/src/__tests__/inline-platform-plugin-test.js
+++ b/packages/react-native-babel-preset/src/__tests__/inline-platform-plugin-test.js
@@ -308,6 +308,24 @@ describe('unsafe positions', () => {
     expect(output).toContain('delete Platform.OS');
   });
 
+  test('does not replace a target nested in an assignment pattern', () => {
+    expectUnchanged(`
+      import {Platform} from 'react-native';
+      [Platform.OS] = values;
+      ({os: Platform.OS} = value);
+    `);
+  });
+
+  test('does not replace for-in or for-of assignment targets', () => {
+    expectUnchanged(`
+      import {Platform} from 'react-native';
+      for (Platform.OS in object) {}
+      for ([Platform.OS] in nestedObject) {}
+      for (Platform.OS of values) {}
+      for ([Platform.OS] of nestedValues) {}
+    `);
+  });
+
   test('does not inline computed access', () => {
     const output = transform(`
       import {Platform} from 'react-native';
diff --git a/packages/react-native-babel-preset/src/inline-platform-plugin.js b/packages/react-native-babel-preset/src/inline-platform-plugin.js
index c818ff3331d..dae21540364 100644
--- a/packages/react-native-babel-preset/src/inline-platform-plugin.js
+++ b/packages/react-native-babel-preset/src/inline-platform-plugin.js
@@ -395,15 +395,31 @@ module.exports = function inlinePlatformPlugin(
   function isWriteTarget(
     path /*: NodePath<MemberExpression> */,
   ) /*: boolean */ {
-    const {parent, node} = path;
-    if (parent.type === 'AssignmentExpression' && parent.left === node) {
-      return true;
-    }
-    if (parent.type === 'UpdateExpression' && parent.argument === node) {
-      return true;
-    }
-    if (parent.type === 'UnaryExpression' && parent.operator === 'delete') {
-      return true;
+    let child /*: Node */ = path.node;
+    let parentPath = path.parentPath;
+
+    while (parentPath != null) {
+      const parent = parentPath.node;
+      if (
+        (parent.type === 'AssignmentExpression' ||
+          parent.type === 'ForInStatement' ||
+          parent.type === 'ForOfStatement') &&
+        parent.left === child
+      ) {
+        return true;
+      }
+      if (parent.type === 'UpdateExpression' && parent.argument === child) {
+        return true;
+      }
+      if (
+        parent.type === 'UnaryExpression' &&
+        parent.operator === 'delete' &&
+        parent.argument === child
+      ) {
+        return true;
+      }
+      child = parent;
+      parentPath = parentPath.parentPath;
     }
     return false;
   }

From a7af44d27d4c0a693aa891d40e8feda717f13395 Mon Sep 17 00:00:00 2001
From: Oskar Eichler <oskar@songstats.com>
Date: Mon, 31 Aug 2026 17:01:16 +0700
Subject: [PATCH 2/2] Keep reads inside write targets inlineable

---
 .../src/__tests__/inline-platform-plugin-test.js     | 12 ++++++++++++
 .../src/inline-platform-plugin.js                    | 11 +++++++++++
 2 files changed, 23 insertions(+)

diff --git a/packages/react-native-babel-preset/src/__tests__/inline-platform-plugin-test.js b/packages/react-native-babel-preset/src/__tests__/inline-platform-plugin-test.js
index 8632b1a7141..c5d32add21c 100644
--- a/packages/react-native-babel-preset/src/__tests__/inline-platform-plugin-test.js
+++ b/packages/react-native-babel-preset/src/__tests__/inline-platform-plugin-test.js
@@ -316,6 +316,18 @@ describe('unsafe positions', () => {
     `);
   });
 
+  test('replaces reads nested inside an assignment target', () => {
+    const output = transform(`
+      import {Platform} from 'react-native';
+      target[Platform.OS] = value;
+      [target[Platform.OS]] = values;
+      ({[Platform.OS]: target} = value);
+    `);
+
+    expect(output).not.toContain('Platform.OS');
+    expect(output.match(/"ios"/g)).toHaveLength(3);
+  });
+
   test('does not replace for-in or for-of assignment targets', () => {
     expectUnchanged(`
       import {Platform} from 'react-native';
diff --git a/packages/react-native-babel-preset/src/inline-platform-plugin.js b/packages/react-native-babel-preset/src/inline-platform-plugin.js
index dae21540364..ecc198882ef 100644
--- a/packages/react-native-babel-preset/src/inline-platform-plugin.js
+++ b/packages/react-native-babel-preset/src/inline-platform-plugin.js
@@ -418,6 +418,17 @@ module.exports = function inlinePlatformPlugin(
       ) {
         return true;
       }
+
+      const nestedWriteTarget =
+        parent.type === 'ArrayPattern' ||
+        parent.type === 'ObjectPattern' ||
+        (parent.type === 'ObjectProperty' && parent.value === child) ||
+        (parent.type === 'RestElement' && parent.argument === child) ||
+        (parent.type === 'AssignmentPattern' && parent.left === child);
+      if (!nestedWriteTarget) {
+        return false;
+      }
+
       child = parent;
       parentPath = parentPath.parentPath;
     }