title: How to run Mocha tests written in TypeScript?
body: <p>Setup: I have a Node project (pure Node, no browser bits) written in TypeScript. I can use the TypeScript compiler (<code>tsc</code>) from the <code>typescript</code> module to compile the code. So far so good.</p>
  
  <p>However, I want to write tests using Mocha, and that's where I'm having trouble. I tried <code>--compilers ts:typescript</code>, but I keep getting errors like:</p>
  
  <pre><code>error TS5023: Unknown compiler option 'compilers'.
  </code></pre>
  
  <p>It looks like the command line to <code>mocha</code> ends up being passed to <code>tsc</code>, which is obviously not good.</p>