title: PHPUnit - 'No tests executed' when using configuration file
body: <h1>The Problem</h1>
  
  <p>To improve my quality of code, I've decided to try to learn how to test my code using Unit Testing instead of my mediocre-at-best testing solutions.</p>
  
  <p>I decided to install PHPUnit using composer for a personal library that allows me to achieve common database functions. At first I didn't have a configuration file for PHPUnit and when I ran commands like:</p>
  
  <pre><code>$ phpunit tests/GeneralStringFunctions/GeneralStringFunctionsTest
  </code></pre>
  
  <p>Please note that this is a terminal command, so I didn't include the <code>.php</code> extension. The GeneralStringFunctionsTest referred to above is actually a <code>GeneralStringFunctionsTest.php</code> file.</p>
  
  <p>The output is what I expected:</p>
  
  <blockquote>
    <p>Time: 31 ms, Memory: 2.75Mb</p>
    
    <p>OK (1 test, 1 assertion)</p>
  </blockquote>
  
  <p>I then tried to use a configuration file to automatically load the test suite instead of having to manually type in the file every time. I created a file called <code>phpunit.xml</code> in my root directory, and entered the following into the file: <a href="http://pastebin.com/0j0L4WBD">http://pastebin.com/0j0L4WBD</a>:</p>
  
  <pre><code>&lt;?xml version = "1.0" encoding="UTF-8" ?&gt;
  &lt;phpunit&gt;
      &lt;testsuites&gt;
          &lt;testsuite name="Tests"&gt;
              &lt;directory&gt;tests&lt;/directory&gt;
          &lt;/testsuite&gt;
      &lt;/testsuites&gt;
  &lt;/phpunit&gt;
  </code></pre>
  
  <p>Now, when I run the command:</p>
  
  <pre><code>phpunit
  </code></pre>
  
  <p>I get the following output:</p>
  
  <blockquote>
    <p>PHPUnit 4.5.0 by Sebastian Bergmann and contributors.</p>
    
    <p>Configuration read from /Users/muyiwa/Projects/DatabaseHelper/phpunit.xml</p>
    
    <p>Time: 16 ms, Memory: 1.50Mb</p>
    
    <p>No tests executed!</p>
  </blockquote>
  
  <p>In case it's helpful, my directory structure is as follows:<br>
  src - Top level directory (with all my source code)<br>
  tests - Top level directory (with all my tests, structured the same as my <em>src</em> folder)<br>
  vendor - Composer third party files  </p>
  
  <p>I also have the composer json and lock file, as well as the phpunit xml file in the top level as files.</p>
  
  <h1>Things I've Tried</h1>
  
  <ul>
  <li>Changing the directory in <code>phpunit.xml</code> to <code>tests/GeneralStringFunctions</code></li>
  <li>Changing the directory in <code>phpunit.xml</code> to <code>./tests</code></li>
  <li>Moving the <code>phpunit.xml</code> file to the <code>tests</code> directory and then changing the directory to be <code>./</code> instead of <code>tests</code>.</li>
  <li>Adding a suffix attribute to the directory tag in <code>phpunit.xml</code> to specify "Tests" as the explicit suffix.</li>
  </ul>