...nderPlainTest.php => RendererRecursionTest.php} | 39 +++++++++++++++-------
 1 file changed, 27 insertions(+), 12 deletions(-)

diff --git a/core/tests/Drupal/Tests/Core/Render/RendererRenderPlainTest.php b/core/tests/Drupal/Tests/Core/Render/RendererRecursionTest.php
similarity index 84%
rename from core/tests/Drupal/Tests/Core/Render/RendererRenderPlainTest.php
rename to core/tests/Drupal/Tests/Core/Render/RendererRecursionTest.php
index 8337b5e..e9a4527 100644
--- a/core/tests/Drupal/Tests/Core/Render/RendererRenderPlainTest.php
+++ b/core/tests/Drupal/Tests/Core/Render/RendererRecursionTest.php
@@ -2,7 +2,7 @@
 
 /**
  * @file
- * Contains \Drupal\Tests\Core\Render\RendererTest.
+ * Contains \Drupal\Tests\Core\Render\RendererRecursionTest.
  */
 
 namespace Drupal\Tests\Core\Render;
@@ -13,9 +13,9 @@
  * @coversDefaultClass \Drupal\Core\Render\Renderer
  * @group Render
  */
-class RendererRenderPlainTest extends RendererTestBase {
+class RendererRecursionTest extends RendererTestBase {
 
-  protected function setupRenderPlainComplexElements() {
+  protected function setUpRenderPlainComplexElements() {
     $complex_child_markup = '<p>Imagine this is a render array for an entity.</p>';
     $parent_markup = '<p>Rendered!</p>';
 
@@ -42,15 +42,17 @@ protected function setupRenderPlainComplexElements() {
   }
 
   /**
+   * ::renderRoot() may not be called inside of another ::renderRoot() call.
+   *
+   * @covers ::renderRoot
+   *
    * @expectedException \LogicException
    */
   public function testRenderPlainWithNestedRenderRoot() {
-    list($complex_child_markup, $parent_markup, $complex_child_template) = $this->setupRenderPlainComplexElements();
+    list($complex_child_markup, $parent_markup, $complex_child_template) = $this->setUpRenderPlainComplexElements();
     $renderer = $this->renderer;
     $this->setUpRequest();
 
-    // Case 1: ::renderRoot() with nested ::renderRoot().
-    // 'Renderer::renderRoot() may not be called inside of another Renderer::renderRoot() call, this must trigger an exception.');
     $complex_child = $complex_child_template;
     $callable = function () use ($renderer, $complex_child) {
       $renderer->renderRoot($complex_child);
@@ -75,13 +77,20 @@ public function testRenderPlainWithNestedRenderRoot() {
     $renderer->renderRoot($page);
   }
 
+  /**
+   * ::render() may be called from anywhere.
+   *
+   * Including from inside of another ::renderRoot() call. Bubbling must be
+   * performed.
+   *
+   * @covers ::renderRoot
+   * @covers ::render
+   */
   public function testRenderPlainWithNestedRender() {
-    list($complex_child_markup, $parent_markup, $complex_child_template) = $this->setupRenderPlainComplexElements();
+    list($complex_child_markup, $parent_markup, $complex_child_template) = $this->setUpRenderPlainComplexElements();
     $renderer = $this->renderer;
     $this->setUpRequest();
 
-    // Case 2: ::renderRoot() with nested ::render().
-    // Renderer::render() may be called from anywhere, including from inside of another Renderer::renderRoot() call. Bubbling must be performed.');
     $complex_child = $complex_child_template;
 
     $callable = function ($elements) use ($renderer, $complex_child, $complex_child_markup, $parent_markup) {
@@ -113,13 +122,19 @@ public function testRenderPlainWithNestedRender() {
     $this->assertTrue(in_array('core/drupal', $page['#attached']['library']), 'Asset bubbling performed.');
   }
 
+  /**
+   * ::renderPlain() may be called from anywhere.
+   *
+   * Including from inside of another ::renderRoot() call.
+   *
+   * @covers ::renderRoot
+   * @covers ::renderPlain
+   */
   public function testRenderPlainWithNestedRenderPlain() {
-    list($complex_child_markup, $parent_markup, $complex_child_template) = $this->setupRenderPlainComplexElements();
+    list($complex_child_markup, $parent_markup, $complex_child_template) = $this->setUpRenderPlainComplexElements();
     $renderer = $this->renderer;
     $this->setUpRequest();
 
-    // Case 3: ::renderRoot() with nested ::renderPlain().
-    // 'Renderer::renderPlain() may be called from anywhere, including from inside of another Renderer::renderRoot() call.');
     $complex_child = $complex_child_template;
 
     $callable = function ($elements) use ($renderer, $complex_child, $parent_markup) {