sourcemap for bundle

vite-plugin-force-terser.js

@@ -1,26 +1,43 @@
 import { readFile, writeFile } from 'fs/promises';
+import path from 'node:path';
 import { minify } from 'terser';
 
 export default function forceTerserPlugin({ filePath }) {
+    const mapPath = `${filePath}.map`;
+    const fileName = path.basename(filePath);
+    const mapFileName = path.basename(mapPath);
+
     return {
         name: 'vite-plugin-force-terser',
         apply: 'build',
-        closeBundle: async () => {
+        async closeBundle() {
-            const code = await readFile(filePath, 'utf-8');
+            const [code, prevMap] = await Promise.all([
+                readFile(filePath, 'utf-8'),
+                readFile(mapPath, 'utf-8')
+            ]);
 
-            const result = await minify(code, {
+            const result = await minify(
+                { [fileName]: code },
+                {
                     compress: true,
                     mangle: true,
-                format: {
+                    format: { comments: false },
-                    comments: false
+                    sourceMap: {
+                        content: prevMap,
+                        filename: fileName,
+                        url: mapFileName
                     }
-            });
+                }
+            );
 
-            if (result.code) {
+            if (result.code && result.map) {
-                await writeFile(filePath, result.code, 'utf-8');
+                await Promise.all([
-                console.log(`✔ ${filePath} minified with terser`);
+                    writeFile(filePath, result.code, 'utf-8'),
+                    writeFile(mapPath, result.map,  'utf-8'),
+                ]);
+                console.log(`✔ ${fileName} and ${mapFileName} regenerated with Terser`);
             } else {
-                console.warn('⚠ terser did not return any code');
+                console.warn('⚠ terser did not return code or map');
             }
         }
     };

vite.config.mts

@@ -26,11 +26,12 @@ export default function ({mode}: { mode: 'development' | 'production' }) {
             },
             emptyOutDir: true,
             outDir: path.resolve(__dirname, './lib'),
-            sourcemap: isDev,
+            sourcemap: true,
             rollupOptions: {
                 output: {
                     entryFileNames: `og.[format].js`,
-                    assetFileNames: `[name][extname]`
+                    assetFileNames: `[name][extname]`,
+                    sourcemapExcludeSources: true,
                 },
                 plugins: [
                     // doesn't work for esm modules