BUGS-6563: Tests STDOUT testing.

Author: Ryan Wagner

behat.yml

@@ -8,6 +8,7 @@ default:
         - Behat\MinkExtension\Context\MinkContext
         - PantheonSystems\PantheonWordPressUpstreamTests\Behat\AdminLogIn
         - PantheonSystems\PantheonWordPressUpstreamTests\Behat\ResponseHeader
+        - WP_CLI\Tests\Context\FeatureContext
     core:
       filters:
         tags: "~@upstreamonly"

tests/behat/wp-native-php-sessions.feature

@@ -23,6 +23,12 @@ Feature: WP Native PHP Sessions plugin
     When I go to "/?action=wpnps_get_session&key=foo"
     Then I should see "(foo:)"
 
+    When I run `echo "foo"`
+    Then STDOUT should CONTAIN
+      """
+      foo
+      """
+
   Scenario: Plugin handles session CRUD operation (logged in)
     Given I log in as an admin