title: const already declared in ES6 switch block
body: <p>Consider the file <code>sample.es6</code></p>
  
  <pre><code>switch (1) {
      case 1:
          const foo = 1;
          break;
      case 2:
          const foo = 2;
          break;
  }
  </code></pre>
  
  <p>If I run it with Node I got</p>
  
  <pre><code>$ node --version
  v4.2.11
  $ node sample.es6 
  /tmp/sample.es6:6
  const foo = 2;
  ^
  
  SyntaxError: Identifier 'foo' has already been declared
      at Object.&lt;anonymous&gt; (/tmp/sample.es6:1:11)
      at Module._compile (module.js:435:26)
      at Object.Module._extensions..js (module.js:442:10)
      at Module.load (module.js:356:32)
      at Function.Module._load (module.js:311:12)
      at Function.Module.runMain (module.js:467:10)
      at startup (node.js:134:18)
      at node.js:961:3
  </code></pre>
  
  <p>Why I'm getting this error? Node shouldn't evaluate <code>const foo = 2;</code>.</p>