title: PSR-4 namespace conventions for folders on same level as src
body: <p>The current convention for PSR-4 is to namespace the <code>src</code> folder as <code>Vendor\Package</code>. Any file within is then namespaced using the directory structure. so</p>
  
  <pre><code>src/Model/MyModel.php
  </code></pre>
  
  <p>uses</p>
  
  <pre><code>namespace Vendor\Package\Model;
  
  class MyModel {...}
  </code></pre>
  
  <p>This is intuitive for any folders within the <code>src</code> folder, but what is the convention for folders on the same level as <code>src</code>? For example <code>tests</code>, <code>public</code>, <code>config</code> etc etc</p>
  
  <p>(I understand some people will comment about the point of namespacing tests but image a large project with lots of individual packages each with their own tests but with common tests that can be reused between packages.)</p>
  
  <p>I have seen suggestions of using <code>Vendor\Package\Tests</code> but to me, following the <code>src</code> convention, this gives the impression that there is a <code>Tests</code> folder within <code>src</code>, which is not the case. Although if there <em>was</em> a <code>Tests</code> folder within <code>src</code> then those namespaces would conflict?</p>