🛠 Add postinstall script to check node version

Author: Shastel

README.md

@@ -57,6 +57,10 @@ Should return index of specified value or -1 if list doesn't contain such
 
 ---
 
+### Notes
+1. We recommend you to use nodejs of version 10 or lower. If you using any of features that does not supported by node v10, score won't be submitted.
+2. Please be sure that each of your test in limit of 30sec.
+
 ---
 
 © [Shastel](https://github.com/Shastel)

package-lock.json

@@ -4,9 +4,13 @@
     "description": "",
     "scripts": {
         "test": "mocha -r ./test/setup-mocha.js",
-        "start": "webpack-dev-server"
+        "start": "webpack-dev-server",
+        "postinstall": "node postinstall.js"
     },
     "author": "",
+    "engines": {
+      "node": "<=10"
+    },
     "license": "ISC",
     "devDependencies": {
         "chai": "^3.5.0",
@@ -15,5 +19,9 @@
         "sinon-chai": "^2.8.0",
         "webpack": "^1.13.1",
         "webpack-dev-server": "^1.14.1"
+    },
+    "dependencies": {
+        "colors": "^1.4.0",
+        "semver": "^6.3.0"
     }
 }

package.json

@@ -0,0 +1,13 @@
+const semver = require('semver');
+const colors = require('colors/safe');
+
+const { engines: { node: nodeVersion }} = require('./package');
+
+if (!semver.satisfies(process.version, nodeVersion)) {
+  process.emitWarning(
+    colors.red(`
+      For this task we are strictly recomend you to use node ${nodeVersion}.
+      Now you are using node ${process.version}, if you are using any of features that not supported by node ${nodeVersion}, score won't be submitted
+    `)
+  );
+}