--- /dev/null
+<?php
+
+namespace Drupal\user\Tests;
+
+use Drupal\Core\Test\AssertMailTrait;
+
+/**
+ * Helper function for logging in from reset password email.
+ */
+trait UserResetEmailTestTrait {
+
+ use AssertMailTrait {
+ getMails as drupalGetMails;
+ }
+
+ /**
+ * Login from reset password email.
+ */
+ protected function loginFromResetEmail() {
+ $_emails = $this->drupalGetMails();
+ $email = end($_emails);
+ $urls = [];
+ preg_match('#.+user/reset/.+#', $email['body'], $urls);
+ $resetURL = $urls[0];
+ $this->drupalGet($resetURL);
+ $this->drupalPostForm(NULL, NULL, 'Log in');
+ }
+
+}