build: do type check

How could babel give up on this

package.json

@@ -45,6 +45,7 @@
     "eslint": "^5.15.0",
     "eslint-plugin-babel": "^5.1.0",
     "file-loader": "^3.0.1",
+    "fork-ts-checker-webpack-plugin": "^0.5.2",
     "fsevents": "^1.2.4",
     "json-loader": "^0.5.7",
     "less": "^3.9.0",

webpack.config.js

@@ -1,5 +1,6 @@
 const webpack = require('webpack')
 const CopyWebpackPlugin = require('copy-webpack-plugin')
+const ForkTsCheckerWebpackPlugin = require('fork-ts-checker-webpack-plugin')
 const TerserPlugin = require('terser-webpack-plugin');
 const path = require('path')
 
@@ -17,6 +18,7 @@ const plugins = [
       to: 'icons/[name].[ext]',
     },
   ]),
+  new ForkTsCheckerWebpackPlugin(),
   new webpack.SourceMapDevToolPlugin({}),
 ]