Issue #2787655: Fix \Drupal\Tests\Core\Form\FormTestBase to not have multiple namespaces

core/tests/Drupal/Tests/Core/Form/FormTestBase.php

 <?php
 
-namespace Drupal\Tests\Core\Form {
+namespace Drupal\Tests\Core\Form;
 
 use Drupal\Component\Utility\Html;
 use Drupal\Core\Form\FormBuilder;
@@ -147,6 +147,9 @@ abstract class FormTestBase extends UnitTestCase {
   protected function setUp() {
     parent::setUp();
 
+    // Add functions to the global namespace for testing.
+    require_once __DIR__ . '/fixtures/form_base_test.inc';
+
     $this->moduleHandler = $this->getMock('Drupal\Core\Extension\ModuleHandlerInterface');
 
     $this->formCache = $this->getMock('Drupal\Core\Form\FormCacheInterface');
@@ -311,35 +314,3 @@ public function getInfo($type) {
   }
 
 }
-
-}
-
-namespace {
-
-  function test_form_id() {
-    $form['test'] = array(
-      '#type' => 'textfield',
-      '#title' => 'Test',
-    );
-    $form['options'] = array(
-      '#type' => 'radios',
-      '#options' => array(
-        'foo' => 'foo',
-        'bar' => 'bar',
-      ),
-    );
-    $form['value'] = array(
-      '#type' => 'value',
-      '#value' => 'bananas',
-    );
-    $form['actions'] = array(
-      '#type' => 'actions',
-    );
-    $form['actions']['submit'] = array(
-      '#type' => 'submit',
-      '#value' => 'Submit',
-    );
-    return $form;
-  }
-
-}

core/tests/Drupal/Tests/Core/Form/fixtures/form_base_test.inc

+<?php
+
+/**
+ * @file
+ * Functions in the global namespace for \Drupal\Tests\Core\Form\FormTestBase.
+ */
+
+/**
+ * Creates a test form.
+ *
+ * @return array
+ *   The form array
+ */
+function test_form_id() {
+  $form['test'] = array(
+    '#type' => 'textfield',
+    '#title' => 'Test',
+  );
+  $form['options'] = array(
+    '#type' => 'radios',
+    '#options' => array(
+      'foo' => 'foo',
+      'bar' => 'bar',
+    ),
+  );
+  $form['value'] = array(
+    '#type' => 'value',
+    '#value' => 'bananas',
+  );
+  $form['actions'] = array(
+    '#type' => 'actions',
+  );
+  $form['actions']['submit'] = array(
+    '#type' => 'submit',
+    '#value' => 'Submit',
+  );
+  return $form;
+}