Reproduce Issue 25484 nextjs vercel/next.js#25484

deep.thought.js

@@ -0,0 +1,7 @@
+import { guid } from "@/scripts/util";
+
+self.onmessage = ({ data: { question } }) => {
+  self.postMessage({
+    answer: guid(),
+  });
+};

jsconfig.json

@@ -0,0 +1,18 @@
+{
+  "compilerOptions": {
+    "baseUrl": ".",
+    "paths": {
+      "@/src/*": ["src/*"],
+      "@/components/*": ["src/components/*"],
+      "@/functions/*": ["src/components/functions/*"],
+      "@/services/*": ["src/components/services/*"],
+      "@/workers/*": ["src/components/workers/*"],
+      "@/context/*": ["src/context/*"],
+      "@/data/*": ["src/data/*"],
+      "@/scripts/*": ["src/scripts/*"],
+      "@/store/*": ["store/*"],
+      "@/__mocks__/*": ["__mocks__/*"],
+      "@/pages/*": ["pages/*"]
+    }
+  }
+}

next.config.js

@@ -0,0 +1,42 @@
+const nextConfig = {
+  serverRuntimeConfig: {
+    // Will only be available on the server side
+    mySecret: 'secret',
+    secondSecret: process.env.SECOND_SECRET, // Pass through env variables
+  },
+  publicRuntimeConfig: {
+    // Will be available on both server and client
+    staticFolder: '/static',
+    butthead: true
+  },
+  webpack: (config, options) => {
+    config.optimization.splitChunks = {
+      chunks: (chunk) => !/^(polyfills|main|pages\/_app)$/.test(chunk.name),
+      minSize: 20000,
+      minRemainingSize: 0,
+      minChunks: 1,
+      maxAsyncRequests: 30,
+      maxInitialRequests: 25,
+      enforceSizeThreshold: 50000,
+      cacheGroups: {
+        defaultVendors: false,
+        default: false,
+        framework: {
+          chunks: 'all',
+          name: 'framework',
+          test: /(?<!node_modules.*)[\\/]node_modules[\\/](react|react-dom|scheduler|prop-types|use-subscription)[\\/]/,
+          priority: 40,
+          enforce: true,
+        },
+        commons: {
+          name: 'commons',
+          minChunks: 1,
+          priority: 20,
+        },
+      },
+    }
+    return config;
+  },
+};
+
+module.exports = nextConfig;