MAGETWO-69240: Unit Tests have different behavior between run for a bunch and a single test

Author: igrybkov

dev/tests/unit/phpunit.xml.dist

@@ -38,6 +38,9 @@
             </exclude>
         </whitelist>
     </filter>
+    <listeners>
+        <listener class="Magento\Framework\TestFramework\Unit\Listener\ReplaceObjectManager"/>
+    </listeners>
     <logging>
         <!--coverage_html_placeholder
             <log type="coverage-html" target="{{coverage_dir}}/test-reports/coverage" charset="UTF-8" yui="true" highlight="true"/>

lib/internal/Magento/Framework/TestFramework/Unit/Listener/ReplaceObjectManager.php

@@ -0,0 +1,43 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+namespace Magento\Framework\TestFramework\Unit\Listener;
+
+
+use Magento\Framework\App\ObjectManager;
+use Magento\Framework\ObjectManagerInterface;
+use Magento\Framework\TestFramework\Unit\Model\ObjectManager as ObjectManagerMock;
+
+/**
+ * The event listener which instantiates ObjectManager before test run
+ */
+class ReplaceObjectManager extends \PHPUnit_Framework_BaseTestListener
+{
+    /**
+     * @var ObjectManagerInterface
+     */
+    private $objectManager;
+
+    /**
+     * Replaces ObjectManager before run for each test
+     *
+     * Replace existing instance of the Application's ObjectManager with an instance,
+     * defined in the Unit Test framework
+     *
+     * This avoids the issue with a not initialized ObjectManager
+     * and allows to customize its behaviour with expected for unit testing
+     *
+     * @param \PHPUnit_Framework_Test $test
+     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
+     */
+    public function startTest(\PHPUnit_Framework_Test $test)
+    {
+        if (!$this->objectManager) {
+            $this->objectManager = new ObjectManagerMock();
+        }
+        ObjectManager::setInstance($this->objectManager);
+    }
+}

lib/internal/Magento/Framework/TestFramework/Unit/Model/ObjectManager.php

@@ -0,0 +1,65 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+namespace Magento\Framework\TestFramework\Unit\Model;
+
+/**
+ * ObjectManager which throws an exception when its methods are called
+ */
+class ObjectManager implements \Magento\Framework\ObjectManagerInterface
+{
+    /**
+     * Throws an exception for any call of this method.
+     *
+     * {@inheritdoc}
+     *
+     * @throws \RuntimeException
+     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
+     */
+    public function create($type, array $arguments = [])
+    {
+        $this->throwNotMockedObjectManagerException();
+    }
+
+    /**
+     * Throws an exception for any call of this method.
+     *
+     * {@inheritdoc}
+     *
+     * @throws \RuntimeException
+     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
+     */
+    public function get($type)
+    {
+        $this->throwNotMockedObjectManagerException();
+    }
+
+    /**
+     * Throws an exception for any call of this method.
+     *
+     * {@inheritdoc}
+     *
+     * @throws \RuntimeException
+     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
+     */
+    public function configure(array $configuration)
+    {
+        $this->throwNotMockedObjectManagerException();
+    }
+
+    /**
+     * Throws an exception when ObjectManager has been called.
+     *
+     * This exception notifies that a developer should mock the ObjectManager or avoid its usage.
+     *
+     * @return void
+     * @throws \RuntimeException
+     */
+    private function throwNotMockedObjectManagerException()
+    {
+        throw new \RuntimeException('ObjectManager shouldn\'t be used in unit tests without mocking');
+    }
+}