Moved to lazy loading modules and configured build chunking

modified:   package-lock.json
	modified:   package.json
	modified:   src/App.tsx
	modified:   src/screens/ActivePickListScreen.test.tsx
	modified:   src/screens/ActivePickListScreen.tsx
	modified:   src/screens/BarcodeScannerScreen.tsx
	modified:   src/screens/HomeScreen.tsx
	modified:   src/screens/ImportExportScreen.tsx
	modified:   src/screens/ManageAreasScreen.test.tsx
	modified:   src/screens/ManageAreasScreen.tsx
	modified:   src/screens/ManageCategoriesScreen.test.tsx
	modified:   src/screens/ManageCategoriesScreen.tsx
	modified:   src/screens/ManageProductsScreen.test.tsx
	modified:   src/screens/ManageProductsScreen.tsx
	modified:   src/screens/PickListsScreen.test.tsx
	modified:   src/screens/PickListsScreen.tsx
	modified:   src/screens/StartPickListScreen.test.tsx
	modified:   src/screens/StartPickListScreen.tsx
	modified:   tsconfig.json
	modified:   vite.config.ts

package-lock.json

@@ -42,6 +42,7 @@
         "eslint-plugin-react-refresh": "^0.4.24",
         "jsdom": "^27.2.0",
         "msw": "^2.12.3",
+        "rollup-plugin-visualizer": "^6.0.5",
         "typescript": "^5.9.3",
         "typescript-eslint": "^8.47.0",
         "vite": "^7.2.4",
@@ -3425,6 +3426,16 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/define-lazy-prop": {
+      "version": "2.0.0",
+      "resolved": "https://registry.npmjs.org/define-lazy-prop/-/define-lazy-prop-2.0.0.tgz",
+      "integrity": "sha512-Ds09qNh8yw3khSjiJjiUInaGX9xlqZDY7JVryGxdxV7NPeuqQfplOpQ66yJFZut3jLa5zOwkXw1g9EI2uKh4Og==",
+      "dev": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">=8"
+      }
+    },
     "node_modules/dequal": {
       "version": "2.0.3",
       "resolved": "https://registry.npmjs.org/dequal/-/dequal-2.0.3.tgz",
@@ -4256,6 +4267,22 @@
         "url": "https://github.com/sponsors/ljharb"
       }
     },
+    "node_modules/is-docker": {
+      "version": "2.2.1",
+      "resolved": "https://registry.npmjs.org/is-docker/-/is-docker-2.2.1.tgz",
+      "integrity": "sha512-F+i2BKsFrH66iaUFc0woD8sLy8getkwTwtOBjvs56Cx4CgJDeKQeqfz8wAYiSb8JOprWhHH5p77PbmYCvvUuXQ==",
+      "dev": true,
+      "license": "MIT",
+      "bin": {
+        "is-docker": "cli.js"
+      },
+      "engines": {
+        "node": ">=8"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/sindresorhus"
+      }
+    },
     "node_modules/is-extglob": {
       "version": "2.1.1",
       "resolved": "https://registry.npmjs.org/is-extglob/-/is-extglob-2.1.1.tgz",
@@ -4313,6 +4340,19 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/is-wsl": {
+      "version": "2.2.0",
+      "resolved": "https://registry.npmjs.org/is-wsl/-/is-wsl-2.2.0.tgz",
+      "integrity": "sha512-fKzAra0rGJUUBwGBgNkHZuToZcn+TtXHpeCgmkMJMMYx1sQDYaCSyjJBSCa2nH1DGm7s3n1oBnohoVTBaN7Lww==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "is-docker": "^2.0.0"
+      },
+      "engines": {
+        "node": ">=8"
+      }
+    },
     "node_modules/isarray": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/isarray/-/isarray-1.0.0.tgz",
@@ -4806,6 +4846,24 @@
         "node": ">=0.10.0"
       }
     },
+    "node_modules/open": {
+      "version": "8.4.2",
+      "resolved": "https://registry.npmjs.org/open/-/open-8.4.2.tgz",
+      "integrity": "sha512-7x81NCL719oNbsq/3mh+hVrAWmFuEYUqrq/Iw3kUzH8ReypT9QQ0BLoJS7/G9k6N81XjW4qHWtjWwe/9eLy1EQ==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "define-lazy-prop": "^2.0.0",
+        "is-docker": "^2.1.1",
+        "is-wsl": "^2.2.0"
+      },
+      "engines": {
+        "node": ">=12"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/sindresorhus"
+      }
+    },
     "node_modules/optionator": {
       "version": "0.9.4",
       "resolved": "https://registry.npmjs.org/optionator/-/optionator-0.9.4.tgz",
@@ -5393,6 +5451,60 @@
         "fsevents": "~2.3.2"
       }
     },
+    "node_modules/rollup-plugin-visualizer": {
+      "version": "6.0.5",
+      "resolved": "https://registry.npmjs.org/rollup-plugin-visualizer/-/rollup-plugin-visualizer-6.0.5.tgz",
+      "integrity": "sha512-9+HlNgKCVbJDs8tVtjQ43US12eqaiHyyiLMdBwQ7vSZPiHMysGNo2E88TAp1si5wx8NAoYriI2A5kuKfIakmJg==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "open": "^8.0.0",
+        "picomatch": "^4.0.2",
+        "source-map": "^0.7.4",
+        "yargs": "^17.5.1"
+      },
+      "bin": {
+        "rollup-plugin-visualizer": "dist/bin/cli.js"
+      },
+      "engines": {
+        "node": ">=18"
+      },
+      "peerDependencies": {
+        "rolldown": "1.x || ^1.0.0-beta",
+        "rollup": "2.x || 3.x || 4.x"
+      },
+      "peerDependenciesMeta": {
+        "rolldown": {
+          "optional": true
+        },
+        "rollup": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/rollup-plugin-visualizer/node_modules/picomatch": {
+      "version": "4.0.3",
+      "resolved": "https://registry.npmjs.org/picomatch/-/picomatch-4.0.3.tgz",
+      "integrity": "sha512-5gTmgEY/sqK6gFXLIsQNH19lWb4ebPDLA4SdLP7dsWkIXHWlG66oPuVvXSGFPppYZz8ZDZq0dYYrbHfBCVUb1Q==",
+      "dev": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">=12"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/jonschlinkert"
+      }
+    },
+    "node_modules/rollup-plugin-visualizer/node_modules/source-map": {
+      "version": "0.7.6",
+      "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.7.6.tgz",
+      "integrity": "sha512-i5uvt8C3ikiWeNZSVZNWcfZPItFQOsYTUAOkcUPGd8DqDy1uOUikjt5dG+uRlwyvR108Fb9DOd4GvXfT0N2/uQ==",
+      "dev": true,
+      "license": "BSD-3-Clause",
+      "engines": {
+        "node": ">= 12"
+      }
+    },
     "node_modules/run-parallel": {
       "version": "1.2.0",
       "resolved": "https://registry.npmjs.org/run-parallel/-/run-parallel-1.2.0.tgz",

package.json

@@ -46,6 +46,7 @@
     "eslint-plugin-react-refresh": "^0.4.24",
     "jsdom": "^27.2.0",
     "msw": "^2.12.3",
+    "rollup-plugin-visualizer": "^6.0.5",
     "typescript": "^5.9.3",
     "typescript-eslint": "^8.47.0",
     "vite": "^7.2.4",

src/App.tsx

@@ -2,16 +2,18 @@ import { CssBaseline, ThemeProvider, createTheme } from '@mui/material';
 import { BrowserRouter, Route, Routes } from 'react-router-dom';
 import { DBProvider } from './context/DBProvider';
 import { AppLayout } from './components/AppLayout';
-import { HomeScreen } from './screens/HomeScreen';
+import React, { Suspense, lazy } from 'react';
-import { StartPickListScreen } from './screens/StartPickListScreen';
-import { PickListsScreen } from './screens/PickListsScreen';
-import { ActivePickListScreen } from './screens/ActivePickListScreen';
-import { ManageProductsScreen } from './screens/ManageProductsScreen';
-import { ManageAreasScreen } from './screens/ManageAreasScreen';
-import { ManageCategoriesScreen } from './screens/ManageCategoriesScreen';
-import { BarcodeScannerScreen } from './screens/BarcodeScannerScreen';
 import { useServiceWorker } from './hooks/useServiceWorker';
-import { ImportExportScreen } from './screens/ImportExportScreen';
+
+const HomeScreen = lazy(() => import('./screens/HomeScreen'));
+const StartPickListScreen = lazy(() => import('./screens/StartPickListScreen'));
+const PickListsScreen = lazy(() => import('./screens/PickListsScreen'));
+const ActivePickListScreen = lazy(() => import('./screens/ActivePickListScreen'));
+const ManageProductsScreen = lazy(() => import('./screens/ManageProductsScreen'));
+const ManageAreasScreen = lazy(() => import('./screens/ManageAreasScreen'));
+const ManageCategoriesScreen = lazy(() => import('./screens/ManageCategoriesScreen'));
+const BarcodeScannerScreen = lazy(() => import('./screens/BarcodeScannerScreen'));
+const ImportExportScreen = lazy(() => import('./screens/ImportExportScreen'));
 
 const theme = createTheme({
   palette: {
@@ -25,19 +27,21 @@ const theme = createTheme({
 const AppRoutes = () => {
   useServiceWorker();
   return (
-    <Routes>
+    <Suspense fallback={<div>Loading…</div>}>
-      <Route element={<AppLayout />}>
+      <Routes>
-        <Route path="/" element={<HomeScreen />} />
+        <Route element={<AppLayout />}>
-        <Route path="/start" element={<StartPickListScreen />} />
+          <Route path="/" element={<HomeScreen />} />
-        <Route path="/pick-lists" element={<PickListsScreen />} />
+          <Route path="/start" element={<StartPickListScreen />} />
-        <Route path="/pick-lists/:id" element={<ActivePickListScreen />} />
+          <Route path="/pick-lists" element={<PickListsScreen />} />
-        <Route path="/products" element={<ManageProductsScreen />} />
+          <Route path="/pick-lists/:id" element={<ActivePickListScreen />} />
-        <Route path="/categories" element={<ManageCategoriesScreen />} />
+          <Route path="/products" element={<ManageProductsScreen />} />
-        <Route path="/areas" element={<ManageAreasScreen />} />
+          <Route path="/categories" element={<ManageCategoriesScreen />} />
-        <Route path="/scan" element={<BarcodeScannerScreen />} />
+          <Route path="/areas" element={<ManageAreasScreen />} />
-        <Route path="/data" element={<ImportExportScreen />} />
+          <Route path="/scan" element={<BarcodeScannerScreen />} />
-      </Route>
+          <Route path="/data" element={<ImportExportScreen />} />
-    </Routes>
+        </Route>
+      </Routes>
+    </Suspense>
   );
 };
 

src/screens/ActivePickListScreen.test.tsx

@@ -2,10 +2,11 @@ import { MemoryRouter, Route, Routes } from 'react-router-dom';
 import { render, screen, within } from '@testing-library/react';
 import userEvent from '@testing-library/user-event';
 import { describe, expect, it, vi, beforeEach } from 'vitest';
-import { ActivePickListScreen } from './ActivePickListScreen';
+import ActivePickListScreen from './ActivePickListScreen';
 import { PickItem } from '../models/PickItem';
 import { Product } from '../models/Product';
 
+//const ActivePickListScreen = lazy(() => import('./screens/ActivePickListScreen'));
 const addMock = vi.fn();
 const updateMock = vi.fn();
 const pickItemsMock = vi.fn<() => PickItem[]>();

src/screens/ActivePickListScreen.tsx

@@ -34,7 +34,7 @@ import { ProductAutocomplete } from '../components/ProductAutocomplete';
 
 const normalizeName = (name: string) => name.trim().toLowerCase();
 
-export const ActivePickListScreen = () => {
+const ActivePickListScreen = () => {
   const { id } = useParams();
   const pickList = usePickList(id);
   const items = usePickItems(id);
@@ -558,3 +558,5 @@ export const ActivePickListScreen = () => {
     </Container>
   );
 };
+
+export default ActivePickListScreen

src/screens/BarcodeScannerScreen.tsx

@@ -26,7 +26,7 @@ interface ProductLookup {
   pickLists: { list: PickList; area?: Area }[];
 }
 
-export const BarcodeScannerScreen = () => {
+const BarcodeScannerScreen = () => {
   const db = useDatabase();
   const navigate = useNavigate();
   const [lastCode, setLastCode] = useState('');
@@ -193,3 +193,5 @@ export const BarcodeScannerScreen = () => {
     </Container>
   );
 };
+
+export default BarcodeScannerScreen

src/screens/HomeScreen.tsx

@@ -1,7 +1,7 @@
 import { Button, Container, Stack, Typography } from '@mui/material';
 import { Link as RouterLink } from 'react-router-dom';
 
-export const HomeScreen = () => (
+const HomeScreen = () => (
   <Container sx={{ py: 4 }}>
     <Typography variant="h4" gutterBottom>
       StockFill
@@ -28,3 +28,5 @@ export const HomeScreen = () => (
     </Stack>
   </Container>
 );
+
+export default HomeScreen;

src/screens/ImportExportScreen.tsx

@@ -19,7 +19,7 @@ import { ImportExportLog } from '../models/ImportExportLog';
 
 const templateFiles: { label: string; file: string }[] = [{ label: 'Products', file: 'products_template.csv' }];
 
-export const ImportExportScreen = () => {
+const ImportExportScreen = () => {
   const db = useDatabase();
   const [logLines, setLogLines] = useState<string[]>([]);
   const [history, setHistory] = useState<ImportExportLog[]>([]);
@@ -176,3 +176,5 @@ export const ImportExportScreen = () => {
     </Box>
   );
 };
+
+export default ImportExportScreen

src/screens/ManageAreasScreen.test.tsx

@@ -2,7 +2,7 @@ import { MemoryRouter } from 'react-router-dom';
 import { render, screen } from '@testing-library/react';
 import userEvent from '@testing-library/user-event';
 import { describe, expect, it, vi } from 'vitest';
-import { ManageAreasScreen } from './ManageAreasScreen';
+import ManageAreasScreen from './ManageAreasScreen';
 
 const areasMock = [{ id: 'area-1', name: 'Front Counter', created_at: 0, updated_at: 0 }];
 

src/screens/ManageAreasScreen.tsx

@@ -20,7 +20,7 @@ import { v4 as uuidv4 } from 'uuid';
 import { useAreas } from '../hooks/dataHooks';
 import { useDatabase } from '../context/DBProvider';
 
-export const ManageAreasScreen = () => {
+const ManageAreasScreen = () => {
   const db = useDatabase();
   const areas = useAreas();
   const [name, setName] = useState('');
@@ -128,3 +128,5 @@ export const ManageAreasScreen = () => {
     </Container>
   );
 };
+
+export default ManageAreasScreen

src/screens/ManageCategoriesScreen.test.tsx

@@ -2,7 +2,7 @@ import { MemoryRouter } from 'react-router-dom';
 import { render, screen } from '@testing-library/react';
 import userEvent from '@testing-library/user-event';
 import { beforeEach, describe, expect, it, vi } from 'vitest';
-import { ManageCategoriesScreen } from './ManageCategoriesScreen';
+import ManageCategoriesScreen from './ManageCategoriesScreen';
 
 const categoriesMock = [{ id: 'cat-1', name: 'Snacks', created_at: 0, updated_at: 0 }];
 const productsMock = [

src/screens/ManageCategoriesScreen.tsx

@@ -20,7 +20,7 @@ import { v4 as uuidv4 } from 'uuid';
 import { useDatabase } from '../context/DBProvider';
 import { useCategories, useProducts } from '../hooks/dataHooks';
 
-export const ManageCategoriesScreen = () => {
+const ManageCategoriesScreen = () => {
   const db = useDatabase();
   const categories = useCategories();
   const products = useProducts();
@@ -198,3 +198,5 @@ const deleteCategory = async (categoryId: string, categoryName: string) => {
     </Container>
   );
 };
+
+export default ManageCategoriesScreen

src/screens/ManageProductsScreen.test.tsx

@@ -4,7 +4,7 @@ import { MemoryRouter } from 'react-router-dom';
 import { fireEvent, render, screen, waitFor, waitForElementToBeRemoved } from '@testing-library/react';
 import userEvent from '@testing-library/user-event';
 import { afterAll, afterEach, beforeAll, beforeEach, describe, expect, it, vi } from 'vitest';
-import { ManageProductsScreen } from './ManageProductsScreen';
+import ManageProductsScreen from './ManageProductsScreen';
 
 let mockScannedBarcode = '123456';
 const mockUseProducts = vi.fn();

src/screens/ManageProductsScreen.tsx

@@ -24,7 +24,7 @@ import { BarcodeScannerView } from '../components/BarcodeScannerView';
 import { ExternalProductInfo, fetchProductFromOFF } from '../modules/openFoodFacts';
 import { DEFAULT_BULK_NAME, DEFAULT_UNIT_TYPE, Product } from '../models/Product';
 
-export const ManageProductsScreen = () => {
+const ManageProductsScreen = () => {
   const db = useDatabase();
   const products = useProducts();
   const categories = useCategories();
@@ -505,3 +505,5 @@ export const ManageProductsScreen = () => {
     </Container>
   );
 };
+
+export default ManageProductsScreen

src/screens/PickListsScreen.test.tsx

@@ -2,7 +2,7 @@ import { MemoryRouter } from 'react-router-dom';
 import { render, screen, within } from '@testing-library/react';
 import userEvent from '@testing-library/user-event';
 import { beforeEach, describe, expect, it, vi } from 'vitest';
-import { PickListsScreen } from './PickListsScreen';
+import PickListsScreen from './PickListsScreen';
 
 let areasMock = [
   { id: 'area-1', name: 'Front Counter', created_at: 0, updated_at: 0 },

src/screens/PickListsScreen.tsx

@@ -22,7 +22,7 @@ import { usePickLists, useAreas } from '../hooks/dataHooks';
 import { useDatabase } from '../context/DBProvider';
 import { PickList } from '../models/PickList';
 
-export const PickListsScreen = () => {
+const PickListsScreen = () => {
   const lists = usePickLists();
   const areas = useAreas();
   const db = useDatabase();
@@ -176,3 +176,5 @@ export const PickListsScreen = () => {
     </Container>
   );
 };
+
+export default PickListsScreen

src/screens/StartPickListScreen.test.tsx

@@ -2,7 +2,7 @@ import { MemoryRouter } from 'react-router-dom';
 import { render, screen, waitFor } from '@testing-library/react';
 import userEvent from '@testing-library/user-event';
 import { beforeEach, describe, expect, it, vi } from 'vitest';
-import { StartPickListScreen } from './StartPickListScreen';
+import StartPickListScreen from './StartPickListScreen';
 
 const navigateMock = vi.fn();
 

src/screens/StartPickListScreen.tsx

@@ -15,7 +15,7 @@ import { v4 as uuidv4 } from 'uuid';
 import { useAreas, useCategories } from '../hooks/dataHooks';
 import { useDatabase } from '../context/DBProvider';
 
-export const StartPickListScreen = () => {
+const StartPickListScreen = () => {
   const areas = useAreas();
   const categories = useCategories();
   const db = useDatabase();
@@ -175,3 +175,5 @@ export const StartPickListScreen = () => {
     </Container>
   );
 };
+
+export default StartPickListScreen

tsconfig.json

@@ -11,7 +11,7 @@
     "noEmit": true,
     "jsx": "react-jsx",
     "strict": true,
-    "types": ["vite/client", "vitest/globals"]
+    "types": ["vite/client", "vitest/globals", "vitest"]
   },
   "include": ["src"],
   "references": [{ "path": "./tsconfig.node.json" }]

vite.config.ts

@@ -1,13 +1,57 @@
 import { defineConfig } from 'vite';
 import react from '@vitejs/plugin-react';
+import { visualizer } from  'rollup-plugin-visualizer';
+
+function packageNameFromId(id: string) {
+  // Extract the package name from a node_modules path, including scoped packages.
+  const match = id.match(/node_modules\/((?:@[^/]+\/)?[^/]+)/);
+  return match ? match[1] : null;
+}
 
 export default defineConfig({
-  plugins: [react()],
+  plugins: [react(), visualizer({ filename: 'dist/stats.html', open: true })],
   server: {
     port: 5173,
   },
   build: {
     outDir: 'dist',
+    minify: 'esbuild', // fast minifier
+    rollupOptions: {
+      output: {
+        manualChunks(id: string) {
+          if (!id) return;
+          if (id.includes('node_modules')) {
+            // Always group react + router into one chunk
+            if (id.includes('react') || id.includes('react-dom') || id.includes('react-router-dom')) {
+              return 'react-vendor';
+            }
+
+            // MUI splits: specific first, generic later
+            if (id.includes('@mui/icons-material')) return 'mui-icons';
+            if (id.includes('@mui/material/esm/styles') || id.includes('@mui/material/styles')) return 'mui-styles';
+            // remaining @mui material code -> mui-core (covers components, utils, etc.)
+            if (id.includes('@mui/material') || id.includes('@mui/base')) return 'mui-core';
+            // emotion / styled engine split
+            if (id.includes('@emotion') || id.includes('@mui/styled-engine')) return 'mui-styled';
+
+
+            // Keep large libs in their own chunk to avoid a huge 'vendor'
+            if (id.includes('jszip')) return 'jszip';
+            if (id.includes('papaparse')) return 'papaparse';
+            if (id.includes('dexie')) return 'dexie';
+            if (id.includes('@zxing')) return 'zxing';
+
+            // Default: create a per-package chunk name so vendor is split up.
+            const pkg = packageNameFromId(id);
+            if (pkg) {
+              // normalize '@' from scoped packages (can't use '/' in filenames)
+              return `npm.${pkg.replace('/', '__').replace('@', '')}`;
+            }
+            return 'vendor';
+          }
+        },
+      },
+    },
   },
   test: {
     include: ['src/**/*.{test,spec}.{ts,tsx}'],