title: Is it possible to use a readonly property in TypeScript Interfaces?
body: <p>I would like to define an interface with a readonly property.  For instance (as a strawman);</p>
  <pre><code>interface foo {
      get bar():bool;
  }
  </code></pre>
  <p>However, this gives the syntax error, &quot;expected ';'&quot; on bar.  I have setup my VisualStudio to use the ES5 target, so getters are supported.  How would I define a readonly property in an interface?</p>