add webpack config

Author: DenisaCG

package.json

@@ -88,6 +88,7 @@
   },
   "jupyterlab": {
     "extension": true,
-    "outputDir": "jupyterlab_lego_boost/labextension"
+    "outputDir": "jupyterlab_lego_boost/labextension",
+    "webpackConfig": "./webpack.config.js"
   }
 }

webpack.config.js

@@ -0,0 +1,17 @@
+// @ts-check
+
+module.exports = /** @type { import('webpack').Configuration } */ ({
+  devtool: 'source-map',
+  module: {
+    rules: [
+      // Load Blockly source maps.
+      {
+        test: /(blockly\/.*\.js)$/,
+        use: [require.resolve('source-map-loader')],
+        enforce: 'pre'
+      }
+    ].filter(Boolean)
+  },
+  // https://github.com/google/blockly-samples/blob/9974e85becaa8ad17e35b588b95391c85865dafd/plugins/dev-scripts/config/webpack.config.js#L118-L120
+  ignoreWarnings: [/Failed to parse source map/]
+});