title: What is the gradlew task assembleAndroidTest and what are the Test applications in Android?
body: <p>I've been coding in React-Native for a while and when I need to I write some native Android code as well. However, I had not seen this gradle task until I started using a library which used this particular gradle task. </p>
  
  <p>That library is an end-to-end testing library (detox), and it uses this command <code>"cd android &amp;&amp; ./gradlew assembleDebug assembleAndroidTest -DtestBuildType=debug &amp;&amp; cd .."</code> to build the android <code>.apk</code> that will be used in the automated e2e test. Actually it builds two apks, the debug one and the AndroidTest one, but I don't know where the latter comes from or where it's configured or where the docs are about this.</p>
  
  <p>I searched for an hour and did not find anything other than this very short description:
  <code>assembleAndroidTest - Assembles all the Test applications.</code></p>
  
  <p>What are the Test applications?</p>
  
  <p>Also, what is <code>-DtestBuildType=debug</code>?</p>