From d5b4955507cca7d0ab773e8f66b6dfaa0c0147d1 Mon Sep 17 00:00:00 2001
From: Kristian Whittick <kristian.whittick@gmail.com>
Date: Sat, 17 Jan 2026 09:47:47 +0000
Subject: [PATCH] fix: replace deprecated Babel plugin-proposal-* with
 plugin-transform-*
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Replaces 6 deprecated Babel plugins with their maintained equivalents:
- @babel/plugin-proposal-class-properties → @babel/plugin-transform-class-properties
- @babel/plugin-proposal-numeric-separator → @babel/plugin-transform-numeric-separator
- @babel/plugin-proposal-nullish-coalescing-operator → @babel/plugin-transform-nullish-coalescing-operator
- @babel/plugin-proposal-optional-chaining → @babel/plugin-transform-optional-chaining
- @babel/plugin-proposal-private-methods → @babel/plugin-transform-private-methods
- @babel/plugin-proposal-private-property-in-object → @babel/plugin-transform-private-property-in-object

These proposals have been merged to the ECMAScript standard and the
proposal plugins are no longer maintained.

Resolves #13651
---
 packages/babel-preset-react-app/create.js    | 18 +++++++++---------
 packages/babel-preset-react-app/package.json | 12 ++++++------
 2 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/packages/babel-preset-react-app/create.js b/packages/babel-preset-react-app/create.js
index 126de46ee5c..b260b699e42 100644
--- a/packages/babel-preset-react-app/create.js
+++ b/packages/babel-preset-react-app/create.js
@@ -148,30 +148,30 @@ module.exports = function (api, opts, env) {
       // See discussion in https://github.com/facebook/create-react-app/issues/4263
       // Note:
       // 'loose' mode configuration must be the same for
-      // * @babel/plugin-proposal-class-properties
-      // * @babel/plugin-proposal-private-methods
-      // * @babel/plugin-proposal-private-property-in-object
+      // * @babel/plugin-transform-class-properties
+      // * @babel/plugin-transform-private-methods
+      // * @babel/plugin-transform-private-property-in-object
       // (when they are enabled)
       [
-        require('@babel/plugin-proposal-class-properties').default,
+        require('@babel/plugin-transform-class-properties').default,
         {
           loose: true,
         },
       ],
       [
-        require('@babel/plugin-proposal-private-methods').default,
+        require('@babel/plugin-transform-private-methods').default,
         {
           loose: true,
         },
       ],
       [
-        require('@babel/plugin-proposal-private-property-in-object').default,
+        require('@babel/plugin-transform-private-property-in-object').default,
         {
           loose: true,
         },
       ],
       // Adds Numeric Separators
-      require('@babel/plugin-proposal-numeric-separator').default,
+      require('@babel/plugin-transform-numeric-separator').default,
       // Polyfills the runtime needed for async/await, generators, and friends
       // https://babeljs.io/docs/en/babel-plugin-transform-runtime
       [
@@ -205,8 +205,8 @@ module.exports = function (api, opts, env) {
       // but not yet supported in webpack due to support missing from acorn.
       // These can be removed once webpack has support.
       // See https://github.com/facebook/create-react-app/issues/8445#issuecomment-588512250
-      require('@babel/plugin-proposal-optional-chaining').default,
-      require('@babel/plugin-proposal-nullish-coalescing-operator').default,
+      require('@babel/plugin-transform-optional-chaining').default,
+      require('@babel/plugin-transform-nullish-coalescing-operator').default,
     ].filter(Boolean),
     overrides: [
       isFlowEnabled && {
diff --git a/packages/babel-preset-react-app/package.json b/packages/babel-preset-react-app/package.json
index b7885c4b657..f627ab613c1 100644
--- a/packages/babel-preset-react-app/package.json
+++ b/packages/babel-preset-react-app/package.json
@@ -22,13 +22,13 @@
   ],
   "dependencies": {
     "@babel/core": "^7.16.0",
-    "@babel/plugin-proposal-class-properties": "^7.16.0",
     "@babel/plugin-proposal-decorators": "^7.16.4",
-    "@babel/plugin-proposal-nullish-coalescing-operator": "^7.16.0",
-    "@babel/plugin-proposal-numeric-separator": "^7.16.0",
-    "@babel/plugin-proposal-optional-chaining": "^7.16.0",
-    "@babel/plugin-proposal-private-methods": "^7.16.0",
-    "@babel/plugin-proposal-private-property-in-object": "^7.16.7",
+    "@babel/plugin-transform-class-properties": "^7.16.0",
+    "@babel/plugin-transform-nullish-coalescing-operator": "^7.16.0",
+    "@babel/plugin-transform-numeric-separator": "^7.16.0",
+    "@babel/plugin-transform-optional-chaining": "^7.16.0",
+    "@babel/plugin-transform-private-methods": "^7.16.0",
+    "@babel/plugin-transform-private-property-in-object": "^7.16.7",
     "@babel/plugin-transform-flow-strip-types": "^7.16.0",
     "@babel/plugin-transform-react-display-name": "^7.16.0",
     "@babel/plugin-transform-runtime": "^7.16.4",