test: run CLI tests with Webpack inspired harness

Author: nschonni

.eslintrc.js

@@ -48,10 +48,13 @@ module.exports = {
       },
     },
     {
-      files: ['**/*.spec.js'],
+      files: ['test/**', '**/*.spec.js'],
       env: {
         jest: true,
       },
+      parserOptions: {
+        ecmaVersion: 2021,
+      },
     },
   ],
 }