title: Getting TypeError: this is not a typed array using Buffer.from in mocha
body: <p>I'm using Mocha / Chai to unit test a library that has recently started using nodejs' Buffer objects to solve a different problem.</p>
  
  <p>I get this error message in the unit test:</p>
  
  <pre><code>TypeError: this is not a typed array. 
  at Function.from (native) 
  at Object.hashesMatch (index.js:29:18
  at Context.&lt;anonymous&gt; (test/test.js:25:22)
  </code></pre>
  
  <p>Line 29 of index.js is where I'm using nodejs' Buffer...</p>
  
  <pre><code>var b = Buffer.from ('some string or other');
  </code></pre>
  
  <p>I can't find a polyfill or workaround so would be grateful for suggestions.</p>
  
  <p>Thanks</p>