enhance tsup

Signed-off-by: Rajesh-Nagarajan-11 <rajeshnagarajan36@gmail.com>

Author: Rajesh-Nagarajan-11

src/custom/Stepper/index.tsx

@@ -1,7 +1,7 @@
 import { Box, Stack, Step, StepConnector, StepLabel, Stepper } from '@mui/material';
 import { stepConnectorClasses } from '@mui/material/StepConnector';
 import { StepIconProps } from '@mui/material/StepIcon';
-import { styled } from '@mui/system';
+import { styled } from '@mui/material/styles';
 import React, { useMemo, useState } from 'react';
 import { IconProps } from '../../icons/types';
 import { useTheme } from '../../theme';

tsup.config.ts

@@ -6,9 +6,14 @@ const env = process.env.NODE_ENV;
 
 // All deps and peerDeps must stay external — re-bundling packages like
 // MUI / emotion breaks CJS ↔ ESM default-export interop at runtime.
-const external = [
+const external: (string | RegExp)[] = [
   ...Object.keys(pkg.dependencies ?? {}),
-  ...Object.keys(pkg.peerDependencies ?? {})
+  ...Object.keys(pkg.peerDependencies ?? {}),
+  // Safety-net: catch transitive @mui/* and @emotion/* sub-packages that
+  // aren't explicitly listed in dependencies (e.g. @mui/system,
+  // @mui/styled-engine, @mui/utils) so they never get re-bundled.
+  /^@mui\//,
+  /^@emotion\//
 ];
 
 export default defineConfig({