title: Running jest from maven with frontend-maven-plugin
body: <p>The docs for jest seem to all assume that we're familiar with the whole yarn/npm/node ecosystem (I'm a java guy, so not so much).</p>
  <p>I've got the following in my <code>pom.xml</code> for running webpack. I just don't know how to extend this so that mvn test will run unit tests in jest</p>
  <pre><code>&lt;plugin&gt;
      &lt;groupId&gt;com.github.eirslett&lt;/groupId&gt;
      &lt;artifactId&gt;frontend-maven-plugin&lt;/artifactId&gt;
      &lt;version&gt;1.6&lt;/version&gt;
      &lt;configuration&gt;
          &lt;installDirectory&gt;target&lt;/installDirectory&gt;
      &lt;/configuration&gt;
      &lt;executions&gt;
          &lt;execution&gt;
              &lt;id&gt;install node and npm&lt;/id&gt;
              &lt;goals&gt;
                  &lt;goal&gt;install-node-and-npm&lt;/goal&gt;
              &lt;/goals&gt;
              &lt;configuration&gt;
                  &lt;nodeVersion&gt;v10.11.0&lt;/nodeVersion&gt;
                  &lt;npmVersion&gt;6.4.1&lt;/npmVersion&gt;
              &lt;/configuration&gt;
          &lt;/execution&gt;
          &lt;execution&gt;
              &lt;id&gt;npm install&lt;/id&gt;
              &lt;goals&gt;
                  &lt;goal&gt;npm&lt;/goal&gt;
              &lt;/goals&gt;
              &lt;configuration&gt;
                  &lt;arguments&gt;install&lt;/arguments&gt;
              &lt;/configuration&gt;
          &lt;/execution&gt;
          &lt;execution&gt;
              &lt;id&gt;webpack build&lt;/id&gt;
              &lt;goals&gt;
                  &lt;goal&gt;webpack&lt;/goal&gt;
              &lt;/goals&gt;
          &lt;/execution&gt;
          &lt;execution&gt;
              &lt;id&gt;test&lt;/id&gt;
              &lt;goals&gt;
                  &lt;goal&gt;yarn&lt;/goal&gt;
              &lt;/goals&gt;
              &lt;phase&gt;test&lt;/phase&gt;
              &lt;configuration&gt;
                  &lt;arguments&gt;test&lt;/arguments&gt;
                  &lt;environmentVariables&gt;
                      &lt;CI&gt;true&lt;/CI&gt;
                  &lt;/environmentVariables&gt;
              &lt;/configuration&gt;
          &lt;/execution&gt;
      &lt;/executions&gt;
  &lt;/plugin&gt;
  </code></pre>