validate git installation upfront

closes #154

Author: jamesgeorge007

.bin/create-rust-webpack.js

@@ -1,11 +1,22 @@
 #!/usr/bin/env node
 
-const { spawnSync } = require("child_process");
+const { execSync, spawnSync } = require("child_process");
 const fs = require("fs");
 const path = require("path");
 const cpr = require("cpr");
 const rimraf = require("rimraf");
 
+function validateInstallation(dep) {
+  let installationStatus;
+  try {
+    execSync(dep, {stdio: 'ignore'});
+    installationStatus = true;
+  } catch (err) {
+    installationStatus = false;
+  }
+  return installationStatus;
+}
+
 function run(cmd, args, opts) {
   const output = spawnSync(cmd, args, opts);
 
@@ -18,6 +29,11 @@ function run(cmd, args, opts) {
   }
 }
 
+if (!validateInstallation("git help -g")) {
+  console.log('\n git is required to be installed!');
+  process.exit(1);
+}
+
 let folderName = '.';
 
 if (process.argv.length >= 3) {