Don't mangle "initSqlJs" function during minification/optimization

The code in sqljs has some custom logic on how the function should be
exported, which I guess breaks the minifier causing it to emit invalid
code when trying to invoke the function from the extension code.
The easiest workaround I found is to exclude the function name from
mangling, which preserves the original name and, when invoked, it
still works.

Fixes #36

package.json

@@ -79,6 +79,7 @@
     "@vscode/test-electron": "^2.4.0",
     "copy-webpack-plugin": "^12.0.2",
     "eslint": "^8.57.0",
+    "terser-webpack-plugin": "^5.3.10",
     "ts-loader": "^9.5.1",
     "typescript": "^5.4.5",
     "webpack": "^5.93.0",

webpack.config.cjs

@@ -7,6 +7,7 @@
 'use strict';
 
 const CopyPlugin = require('copy-webpack-plugin');
+const TerserPlugin = require("terser-webpack-plugin");
 const path = require('path');
 
 //@ts-check
@@ -63,6 +64,19 @@ const extensionConfig = {
         { from: 'node_modules/sql.js/dist/sql-wasm.wasm', to: 'sql-wasm.wasm' }
       ]
     })
-  ]
+  ],
+  optimization: {
+    minimizer: [
+      new TerserPlugin({
+        terserOptions: {
+          mangle: {
+            // don't mangle the "initSqlJs" function, otherwise the whole thing breaks and calling
+            // it from our code fails with "(0, default.l) is not a function"
+            reserved: [ "initSqlJs" ]
+          }
+        }
+      })
+    ]
+  }
 };
 module.exports = [ extensionConfig ];