check node version on postinstall & while initiating a new project

package.json

@@ -13,6 +13,7 @@
     "dev": "babel-node src",
     "lint": "eslint src tests",
     "pretest": "npm run -s build",
+    "postinstall": "node lib/lib/check-engine.js",
     "test": "tape -r babel-register tests/*.test.js | tap-diff",
     "test:build": "babel-node src build --cwd examples/root",
     "test:serve": "npm run -s test:build && babel-node src serve --port 3000 --cwd examples/root",
@@ -115,8 +116,8 @@
     "es6-promisify": "^5.0.0",
     "file-loader": "^0.11.1",
     "fs.promised": "^3.0.0",
-    "html-webpack-plugin": "^2.28.0",
     "html-webpack-exclude-assets-plugin": "0.0.5",
+    "html-webpack-plugin": "^2.28.0",
     "isomorphic-unfetch": "^2.0.0",
     "json-loader": "^0.5.4",
     "less": "^2.7.2",

src/index.js

@@ -8,9 +8,12 @@ import serve from './commands/serve';
 import installHooks from './lib/output-hooks';
 import pkg from '../package.json';
 import logo from './lib/logo';
+import checkVersion from './lib/check-engine';
 
 global.Promise = require('promise-polyfill');
 
+checkVersion();
+
 installHooks();
 
 yargs

src/lib/check-engine.js

@@ -0,0 +1,30 @@
+import { execSync } from "child_process";
+
+import semver from "semver";
+import colors from "chalk";
+import pkg from "./../../package.json";
+
+const platformSuffix = process.platform === "win32" ? ".cmd" : "";
+const node = "node" + platformSuffix;
+
+export default function checkVersion() {
+  const requirements = pkg.engines;
+  const nodeVersion = execSync(node + " --version").toString() || '';
+
+  if ( !(semver.satisfies(nodeVersion, requirements.node)) ) {
+    const errorMessage = colors.yellow(
+      "\n⚠️ " +
+        "preact-cli requires at least " +
+        "node@" +
+        requirements.node +
+        "\n\n" +
+        "Your node version is " +
+        nodeVersion +
+      "\n"
+    );
+		process.stdout.write(errorMessage) + '\n';
+		process.exit(1);
+  }
+
+	return true;
+}