title: ScalaTest: How to mix parallel and sequential tests
body: <p><br />
  Say I have 6 test suites: A B C D E F, and I want A B C to run sequentially and <strong>THEN</strong> run D E F in parrallel. <br />
  With an output like that:</p>
  <pre><code>A
  B
  C // always in that order
  E
  D
  F // The order doesn't matter
  </code></pre>
  <p>The idea is to be able to test ABC in isolation of the rest of the tests.</p>
  <p><strong>What I have already tried</strong></p>
  <p>Create a super sequential test class like that and adding <code>@DoNotDiscover</code> on the sequential tests.</p>
  <pre class="lang-scala prettyprint-override"><code>class MasterSuite extends Stepwise(
    Sequential(new A, new B, new C)
  )
  </code></pre>
  <p>But, even if A B C are run sequentially, then are run in parrallel with the other tests.</p>
  <p>I have also tried that</p>
  <pre class="lang-scala prettyprint-override"><code>class MasterSuite extends Stepwise(
    Sequential(new A, new B, new C),
    Suites(new D, new E, new F)
  )
  </code></pre>
  <p>But for me it run me all tests sequentially (maybe I have miss something in the <code>build.sbt</code> file).</p>