From 84f1391f29f4b14c132b9bc745072144ab6cd49e Mon Sep 17 00:00:00 2001
From: Madison Steiner <awsmadi@amazon.com>
Date: Wed, 11 Mar 2026 00:14:43 +0000
Subject: [PATCH] perf(runtime): enable webpack compress and mangle
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Enable Terser compression and mangling for the jsii runtime bundle.
This reduces bundle size and improves require() time at startup.

- compress: true — enables dead code elimination and constant folding
- mangle: true — shortens local variable names
- keep_classnames: true — preserves class names used in error messages
  (serialization.ts:1296, objects.ts:131) and stack traces
- keep_fnames: true — preserves function names for readable stack traces
  sent to language runtimes via the jsii protocol
- Both keep_* options set at terserOptions top level AND inside mangle
  to protect against both compress and mangle passes

Estimated 10-50ms faster initial require() due to smaller bundle size.
---
 packages/@jsii/runtime/webpack.config.js | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/packages/@jsii/runtime/webpack.config.js b/packages/@jsii/runtime/webpack.config.js
index 81ebe00e7b..f00a6e6ae2 100644
--- a/packages/@jsii/runtime/webpack.config.js
+++ b/packages/@jsii/runtime/webpack.config.js
@@ -38,12 +38,16 @@ module.exports = {
     minimizer: [
       new TerserPlugin({
         terserOptions: {
-          compress: false,
+          keep_classnames: true,
+          keep_fnames: true,
+          compress: true,
           format: {
-            beautify: true,
             comments: 'some',
           },
-          mangle: false,
+          mangle: {
+            keep_classnames: true,
+            keep_fnames: true,
+          },
         },
         extractComments: false,
       }),