--- /dev/null
+<?php
+
+namespace Drupal\php\Tests;
+
+use Drupal\simpletest\WebTestBase;
+
+/**
+ * Test uninstall functionality of PHP module.
+ *
+ * @group PHP
+ */
+class PhpUninstallTest extends WebTestBase {
+
+ /**
+ * Modules to enable.
+ *
+ * @var array
+ */
+ public static $modules = ['php'];
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function setUp() {
+ parent::setUp();
+
+ $permissions = [
+ 'access administration pages',
+ 'administer modules',
+ ];
+
+ // User to set up php.
+ $this->admin_user = $this->drupalCreateUser($permissions);
+ $this->drupalLogin($this->admin_user);
+ }
+
+ /**
+ * Tests if the module cleans up the disk on uninstall.
+ */
+ public function testPhpUninstall() {
+ // If this request is missing the uninstall form shows "The form has become
+ // outdated. Copy any unsaved work in the form below and then reload this
+ // page." message for unknown reasons.
+ $this->drupalGet('admin/modules');
+
+ // Uninstall the module.
+ $edit = [];
+ $edit['uninstall[php]'] = TRUE;
+ $this->drupalPostForm('admin/modules/uninstall', $edit, t('Uninstall'));
+ $this->assertText(t('Would you like to continue with uninstalling the above?'));
+ $this->drupalPostForm(NULL, [], t('Uninstall'));
+ $this->assertText(t('The selected modules have been uninstalled.'));
+ }
+
+}