[code] split helpers into separate files

src/sshKey.js

@@ -0,0 +1,37 @@
+const { writeFileSync } = require('fs');
+const { join } = require('path');
+
+const {
+  validateDir,
+  validateFile
+} = require('./helpers');
+
+const {
+  HOME
+} = process.env;
+
+const addSshKey = (key, name) => {
+  const sshDir = join(HOME || __dirname, '.ssh');
+  const filePath = join(sshDir, name);
+
+  validateDir(sshDir);
+  validateFile(`${sshDir}/known_hosts`);
+
+  try {
+    writeFileSync(filePath, key, {
+      encoding: 'utf8',
+      mode: 0o600
+    });
+  } catch (e) {
+    console.error('⚠️ writeFileSync error', filePath, e.message);
+    process.abort();
+  }
+
+  console.log('✅ Ssh key added to `.ssh` dir ', filePath);
+
+  return filePath;
+};
+
+module.exports = {
+  addSshKey
+}