Improve build pipeline

tsconfig.json

@@ -2,17 +2,15 @@
   "compilerOptions": {
     "outDir": "lib",
     "sourceMap": true,
-    "target": "es5",
-    "downlevelIteration": true,
-    "allowJs": true,
+    "declaration": true,
+    "declarationMap": true,
+    "target": "es6",
     "esModuleInterop": true,
     "strict": true,
     "experimentalDecorators": true,
     "moduleResolution": "Node",
     "module": "es6",
-    "declaration": true,
     "composite": true,
-    "declarationMap": true,
-    "lib": ["es6", "dom", "es2017"]
+    "lib": ["dom", "es2017"]
   }
 }

webpack.config.js

@@ -6,9 +6,6 @@ var PATHS = {
   bundles: path.resolve(__dirname, 'lib'),
 };
 
-const isProduction = process.env.NODE_ENV == 'production';
-const isDevelopment = !isProduction;
-
 module.exports = {
   entry: {
     main: [PATHS.entryPoint],
@@ -31,9 +28,9 @@ module.exports = {
   },
   optimization: {
     minimize: true,
-    usedExports: true,
     minimizer: [
       new TerserJSPlugin({
+        sourceMap: true,
         test: /\.js$/i,
       }),
     ],