docs(bundler): add some docs to bundler.js

crates/metassr-bundler/src/bundle.js

@@ -1,14 +1,20 @@
 const { rspack } = require('@rspack/core');
 const path = require('path');
 
+/**
+ * Safely parses a JSON string, returning undefined if parsing fails.
+ * @param {string} json - The JSON string to parse.
+ * @returns {Object|undefined} - Parsed object or undefined if parsing fails.
+ */
 function safelyParseJSON(json) {
     try {
-        return JSON.parse(json)
+        return JSON.parse(json);
     } catch (_) {
-        return undefined
+        return undefined;
     }
 }
 
+// Default configuration object for rspack bundling process
 let config = {
 
     output: {
@@ -82,39 +88,44 @@ let config = {
             },
         ],
 
-    }
-}
-
+/**
+ * Bundles web resources using rspack.
+ * @param {Object|string} entry - The entry point(s) for the bundling process (can be a string or JSON object).
+ * @param {string} dist - The distribution path where bundled files will be output.
+ * @returns {Promise} - Resolves when bundling is successful, rejects if there is an error.
+ */
 async function web_bundling(entry, dist) {
-
+    // Create a bundler instance using the config and parameters
     const compiler = rspack(
         {
-            ...config,
-            entry: safelyParseJSON(entry) ?? entry,
+            ...config, // Merge with the default config
+            entry: safelyParseJSON(entry) ?? entry, // Parse entry if it's JSON, otherwise use it as is
             output: dist ? {
                 ...config.output,
-                path: path.join(process.cwd(), dist)
+                path: path.join(process.cwd(), dist), // Use current working directory and output path
             } : config.output,
-
-            name: 'Client',
-            mode: 'development',
-            devtool: 'source-map',
-            stats: { preset: 'errors-warnings', timings: true, colors: true },
-            target: 'web',
+            // minimize: true,
+            name: 'Client', // Name of the bundle (Client)
+            mode: 'production', // Set mode to development (for non-minimized builds)
+            devtool: 'source-map', // Enable source maps for better debugging
+            stats: { preset: 'errors-warnings', timings: true, colors: true }, // Customize bundling stats output
+            target: 'web', // Set the target environment to web (for browser usage)
         }
-
     );
 
+    // Return a promise that runs the bundling process and resolves or rejects based on the result
     return new Promise((resolve, reject) => {
         return compiler.run((error, stats) => {
+            // Handle errors during the bundling process
             if (error) {
-                reject(error.message);
+                reject(error.message); // Reject with the error message if bundling fails
             }
 
+            // Check if there are any errors in the bundling stats
             if (error || stats?.hasErrors()) {
-                reject(stats.toString("errors-only"));
+                reject(stats.toString("errors-only")); // Reject with errors-only details from stats
             }
-            resolve(0);
+            resolve(0); // Resolve successfully when bundling is complete
         });
     });
 }