Update index.js

Author: eugene-matvejev

index.js

@@ -1,12 +1,26 @@
 'use strict';
 
-let fs = require('fs'),
-    packageJsonPath = `${process.cwd()}/package.json`,
+const fs = require('fs');
+const Processor = require('./src/processor');
+
+let packageJsonPath = `${process.cwd()}/package.json`,
     packageJsonContent = fs.readFileSync(packageJsonPath),
 /** @param {{extra: {node_parameter_handler: []}}} content */
-    packageJson = JSON.parse(packageJsonContent),
-    Processor = require('./src/processor'),
-    processor = new Processor(packageJson.extra.node_parameter_handler, process.cwd());
+    packageJson = JSON.parse(packageJsonContent);
+
+try {
+    if(undefined === packageJson.extra) {
+        throw `node 'extra' is not defined`;
+    }
+    if(undefined === packageJson.extra.node_parameter_handler) {
+        throw `node 'node_parameter_handler' in 'extra' is not defined`
+    }
+    if(undefined === packageJson.extra.node_parameter_handler) {
+        throw `node 'node_parameter_handler' in 'extra' is not defined`
+    }
+}
+
+const processor = new Processor(packageJson.extra.node_parameter_handler, process.cwd());
 
 processor.process();
 processor.write();