Add a test.

features/blackbox.feature

@@ -86,3 +86,9 @@ Feature: Test DrupalContext
     Given I am on the homepage
     When I click "Download & Extend"
     Then I should see the link "Distributions"
+
+  @scenariotag
+  Scenario: Check tags on feature and scenario
+    Then the "scenariotag" tag should be present
+    And the "blackbox" tag should be present
+    But the "nonexisting" tag should not be present

features/bootstrap/FeatureContext.php

@@ -5,6 +5,7 @@
 use Drupal\DrupalExtension\Context\RawDrupalContext;
 use Drupal\DrupalExtension\Hook\Scope\BeforeNodeCreateScope;
 use Drupal\DrupalExtension\Hook\Scope\EntityScope;
+use Drupal\DrupalExtension\TagTrait;
 use Symfony\Component\Process\PhpExecutableFinder;
 use Symfony\Component\Process\Process;
 
@@ -16,6 +17,9 @@
  * conflicts.
  */
 class FeatureContext extends RawDrupalContext {
+
+    use TagTrait;
+
   /**
    * Hook into node creation to test `@beforeNodeCreate`
    *
@@ -419,6 +423,32 @@ public function itShouldFail($success)
         }
     }
 
+    /**
+     * Checks if the current scenario or feature has the given tag.
+     *
+     * @Then the :tag tag should be present
+     *
+     * @param string $tag
+     *   The tag to check.
+     */
+    public function shouldHaveTag($tag)
+    {
+        PHPUnit_Framework_Assert::assertTrue($this->hasTag($tag));
+    }
+
+    /**
+     * Checks if the current scenario or feature does not have the given tag.
+     *
+     * @Then the :tag tag should not be present
+     *
+     * @param string $tag
+     *   The tag to check.
+     */
+    public function shouldNotHaveTag($tag)
+    {
+        PHPUnit_Framework_Assert::assertFalse($this->hasTag($tag));
+    }
+
     private function getExitCode()
     {
         return $this->process->getExitCode();