Add skeleton of phpunit

phpunit.xml.dist

+<phpunit backupGlobals="false"
+         backupStaticAttributes="false"
+         colors="true"
+         convertErrorsToExceptions="true"
+         convertNoticesToExceptions="true"
+         convertWarningsToExceptions="true"
+         processIsolation="false"
+         stopOnFailure="false"
+         syntaxCheck="false"
+         bootstrap="tests/phpunit/bootstrap.php"
+>
+  <testsuites>
+    <testsuite name="My Test Suite">
+      <directory>./tests/phpunit</directory>
+    </testsuite>
+  </testsuites>
+
+  <filter>
+    <whitelist>
+      <directory suffix=".php">./</directory>
+    </whitelist>
+  </filter>
+
+  <listeners>
+    <listener class="Civi\Test\CiviTestListener">
+      <arguments></arguments>
+    </listener>
+  </listeners>
+</phpunit>

tests/phpunit/bootstrap.php

+<?php
+
+ini_set('memory_limit', '2G');
+ini_set('safe_mode', 0);
+eval(cv('php:boot --level=classloader', 'phpcode'));
+
+/**
+ * Call the "cv" command.
+ *
+ * @param string $cmd
+ *   The rest of the command to send.
+ * @param string $decode
+ *   Ex: 'json' or 'phpcode'.
+ * @return string
+ *   Response output (if the command executed normally).
+ * @throws \RuntimeException
+ *   If the command terminates abnormally.
+ */
+function cv($cmd, $decode = 'json') {
+  $cmd = 'cv ' . $cmd;
+  $descriptorSpec = array(0 => array("pipe", "r"), 1 => array("pipe", "w"), 2 => STDERR);
+  $oldOutput = getenv('CV_OUTPUT');
+  putenv("CV_OUTPUT=json");
+  $process = proc_open($cmd, $descriptorSpec, $pipes, __DIR__);
+  putenv("CV_OUTPUT=$oldOutput");
+  fclose($pipes[0]);
+  $result = stream_get_contents($pipes[1]);
+  fclose($pipes[1]);
+  if (proc_close($process) !== 0) {
+    throw new RuntimeException("Command failed ($cmd):\n$result");
+  }
+  switch ($decode) {
+    case 'raw':
+      return $result;
+
+    case 'phpcode':
+      // If the last output is /*PHPCODE*/, then we managed to complete execution.
+      if (substr(trim($result), 0, 12) !== "/*BEGINPHP*/" || substr(trim($result), -10) !== "/*ENDPHP*/") {
+        throw new \RuntimeException("Command failed ($cmd):\n$result");
+      }
+      return $result;
+
+    case 'json':
+      return json_decode($result, 1);
+
+    default:
+      throw new RuntimeException("Bad decoder format ($decode)");
+  }
+}