clean install

web/core/tests/Drupal/Tests/PhpUnitWarningsTest.php

@@ -0,0 +1,21 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests;
+
+/**
+ * @coversDefaultClass \Drupal\Tests\Traits\PhpUnitWarnings
+ * @group legacy
+ */
+class PhpUnitWarningsTest extends UnitTestCase {
+
+  /**
+   * Tests that selected PHPUnit warning is converted to deprecation.
+   */
+  public function testAddWarning(): void {
+    $this->expectDeprecation('Test warning for \Drupal\Tests\PhpUnitWarningsTest::testAddWarning()');
+    $this->addWarning('Test warning for \Drupal\Tests\PhpUnitWarningsTest::testAddWarning()');
+  }
+
+}