Don't minify symbols in production builds

This disables symbol renaming in production builds. The original
variable and function names are preserved. All other forms of
compression applied by Closure (dead code elimination, inlining, etc)
are unchanged — the final program is identical to what we were
producing before, just in a more readable form.

The motivation is to make it easier to debug React issues that only
occur in production — the same reason we decided to start shipping
sourcemaps in #28827 and #28827.

However, because most apps run their own minification step on their
npm dependencies, it's not necessary for us to minify the symbols
before publishing — it'll be handled the app, if desired.

This is the same strategy Meta has used to ship React for years. The
React build itself has unminified symbols, but they get minified as part
of Meta's regular build pipeline.

Even if an app does not minify their npm dependencies, gzip covers
most of the cost of symbol renaming anyway.

This saves us from having to ship sourcemaps, which means even apps that
don't have sourcemaps configured will be able to debug the React build
as easily as they would any other npm dependency.

Author: acdlite

dangerfile.js

@@ -43,8 +43,8 @@ const SIGNIFICANCE_THRESHOLD = 0.002;
 const CRITICAL_ARTIFACT_PATHS = new Set([
   // We always report changes to these bundles, even if the change is
   // insignificant or non-existent.
-  'oss-stable/react-dom/cjs/react-dom.production.min.js',
-  'oss-experimental/react-dom/cjs/react-dom.production.min.js',
+  'oss-stable/react-dom/cjs/react-dom.production.js',
+  'oss-experimental/react-dom/cjs/react-dom.production.js',
   'facebook-www/ReactDOM-prod.classic.js',
   'facebook-www/ReactDOM-prod.modern.js',
 ]);

fixtures/packaging/systemjs-builder/prod/config.js

@@ -1,9 +1,8 @@
 System.config({
   paths: {
-    react:
-      '../../../../build/oss-experimental/react/umd/react.production.min.js',
+    react: '../../../../build/oss-experimental/react/umd/react.production.js',
     'react-dom':
-      '../../../../build/oss-experimental/react-dom/umd/react-dom.production.min.js',
+      '../../../../build/oss-experimental/react-dom/umd/react-dom.production.js',
     schedule:
       '../../../../build/oss-experimental/scheduler/umd/schedule.development',
   },

package.json

@@ -94,7 +94,6 @@
     "shelljs": "^0.8.5",
     "signedsource": "^2.0.0",
     "targz": "^1.0.1",
-    "terser": "^5.30.3",
     "through2": "^3.0.1",
     "tmp": "^0.1.0",
     "typescript": "^3.7.5",

packages/eslint-plugin-react-hooks/npm/index.js

@@ -3,7 +3,7 @@
 // TODO: this doesn't make sense for an ESLint rule.
 // We need to fix our build process to not create bundles for "raw" packages like this.
 if (process.env.NODE_ENV === 'production') {
-  module.exports = require('./cjs/eslint-plugin-react-hooks.production.min.js');
+  module.exports = require('./cjs/eslint-plugin-react-hooks.production.js');
 } else {
   module.exports = require('./cjs/eslint-plugin-react-hooks.development.js');
 }

packages/jest-react/npm/index.js

@@ -1,7 +1,7 @@
 'use strict';
 
 if (process.env.NODE_ENV === 'production') {
-  module.exports = require('./cjs/jest-react.production.min.js');
+  module.exports = require('./cjs/jest-react.production.js');
 } else {
   module.exports = require('./cjs/jest-react.development.js');
 }

packages/react-art/npm/index.js

@@ -1,7 +1,7 @@
 'use strict';
 
 if (process.env.NODE_ENV === 'production') {
-  module.exports = require('./cjs/react-art.production.min.js');
+  module.exports = require('./cjs/react-art.production.js');
 } else {
   module.exports = require('./cjs/react-art.development.js');
 }

packages/react-cache/npm/index.js

@@ -1,7 +1,7 @@
 'use strict';
 
 if (process.env.NODE_ENV === 'production') {
-  module.exports = require('./cjs/react-cache.production.min.js');
+  module.exports = require('./cjs/react-cache.production.js');
 } else {
   module.exports = require('./cjs/react-cache.development.js');
 }

packages/react-client/npm/flight.js

@@ -1,7 +1,7 @@
 'use strict';
 
 if (process.env.NODE_ENV === 'production') {
-  module.exports = require('./cjs/react-client-flight.production.min.js');
+  module.exports = require('./cjs/react-client-flight.production.js');
 } else {
   module.exports = require('./cjs/react-client-flight.development.js');
 }

packages/react-debug-tools/npm/index.js

@@ -1,7 +1,7 @@
 'use strict';
 
 if (process.env.NODE_ENV === 'production') {
-  module.exports = require('./cjs/react-debug-tools.production.min.js');
+  module.exports = require('./cjs/react-debug-tools.production.js');
 } else {
   module.exports = require('./cjs/react-debug-tools.development.js');
 }

packages/react-dom/npm/index.js

@@ -32,7 +32,7 @@ if (process.env.NODE_ENV === 'production') {
   // DCE check should happen before ReactDOM bundle executes so that
   // DevTools can report bad minification during injection.
   checkDCE();
-  module.exports = require('./cjs/react-dom.production.min.js');
+  module.exports = require('./cjs/react-dom.production.js');
 } else {
   module.exports = require('./cjs/react-dom.development.js');
 }