2.7.5

Export data spreadsheet

build.js

@@ -44,6 +44,13 @@ function cleanDist() {
   for (const f of targets) {
     try { fs.unlinkSync(f); } catch (_) { /* ok if missing */ }
   }
+  // Clean up any previously-generated ESM chunks
+  const chunksDir = path.join(ASSETS, 'chunks');
+  if (fs.existsSync(chunksDir)) {
+    for (const f of fs.readdirSync(chunksDir)) {
+      try { fs.unlinkSync(path.join(chunksDir, f)); } catch (_) {}
+    }
+  }
 }
 
 // Recursively resolve CSS @import statements into one flat string
@@ -80,7 +87,8 @@ function rewriteHTML(html, version) {
     '$1about.min.css?v=' + version + '$2'
   );
   const css = '  <link rel="stylesheet" href="./assets/bundle.min.css?v=' + version + '">';
-  const js  = '  <script defer src="./assets/bundle.min.js?v=' + version + '"></script>';
+  // ESM module — browser loads chunks automatically on demand (e.g. xlsx-js-style)
+  const js  = '  <script type="module" src="./assets/bundle.min.js?v=' + version + '"></script>';
   html = html.replace('</head>', css + '\n' + js + '\n</head>');
   return html;
 }
@@ -110,15 +118,17 @@ async function build() {
   fs.mkdirSync(ASSETS, { recursive: true });
   console.log('  Output dir ready: dist/');
 
-  // 2. Bundle + minify JavaScript
+  // 2. Bundle + minify JavaScript (ESM with code splitting for lazy chunks)
   console.log('  Bundling JS...');
   await esbuild.build({
     entryPoints: [path.join(ROOT, 'assets/js/main.js')],
     bundle:      true,
+    splitting:   true,
     minify:      true,
-    format:      'iife',
-    globalName:  'SunScope',
-    outfile:     path.join(ASSETS, 'bundle.min.js'),
+    format:      'esm',
+    entryNames:  'bundle.min',
+    chunkNames:  'chunks/[name]-[hash]',
+    outdir:      ASSETS,
     logLevel:    'warning',
     plugins:     [stripJSXCommentsPlugin],
   });