Issue #2938969 by msankhala, dhirendra.mishra, paulocs, TR, MerryHamster, alexpott, jofitz, longwave, Manuel Garcia, tameeshb, boaloysius, Yasiru Nilan, xjm, wturrell, ritzz, ZeiP, darrenwh: Replace drupal_render() in docblock and comments outside of @param, @return, @link, @see and outside of @code - @endcode

core/core.api.php

@@ -2419,8 +2419,8 @@ function hook_validation_constraint_alter(array &$definitions) {
  * @code
  * array('#type' => 'status_messages')
  * @endcode
- * to a render array, use drupal_render() to render it, and add a command to
- * place the messages in an appropriate location.
+ * to a render array, use \Drupal::service('renderer')->render() to render it,
+ * and add a command to place the messages in an appropriate location.
  *
  * @section sec_other Other methods for triggering Ajax
  * Here are some additional methods you can use to trigger Ajax responses in

core/includes/common.inc

@@ -413,13 +413,13 @@ function render(&$element) {
 /**
  * Hides an element from later rendering.
  *
- * The first time render() or drupal_render() is called on an element tree,
- * as each element in the tree is rendered, it is marked with a #printed flag
- * and the rendered children of the element are cached. Subsequent calls to
- * render() or drupal_render() will not traverse the child tree of this element
- * again: they will just use the cached children. So if you want to hide an
- * element, be sure to call hide() on the element before its parent tree is
- * rendered for the first time, as it will have no effect on subsequent
+ * The first time render() or RenderInterface::render() is called on an element
+ * tree, as each element in the tree is rendered, it is marked with a #printed
+ * flag and the rendered children of the element are cached. Subsequent calls to
+ * render() or RenderInterface::render() will not traverse the child tree of
+ * this element again: they will just use the cached children. So if you want to
+ * hide an element, be sure to call hide() on the element before its parent tree
+ * is rendered for the first time, as it will have no effect on subsequent
  * renderings of the parent tree.
  *
  * @param $element
@@ -428,6 +428,7 @@ function render(&$element) {
  * @return
  *   The element.
  *
+ * @see \Drupal\Core\Render\RendererInterface
  * @see render()
  * @see show()
  */
@@ -442,13 +443,13 @@ function hide(&$element) {
  * You can also use render($element), which shows the element while rendering
  * it.
  *
- * The first time render() or drupal_render() is called on an element tree,
- * as each element in the tree is rendered, it is marked with a #printed flag
- * and the rendered children of the element are cached. Subsequent calls to
- * render() or drupal_render() will not traverse the child tree of this element
- * again: they will just use the cached children. So if you want to show an
- * element, be sure to call show() on the element before its parent tree is
- * rendered for the first time, as it will have no effect on subsequent
+ * The first time render() or RenderInterface::render() is called on an element
+ * tree, as each element in the tree is rendered, it is marked with a #printed
+ * flag and the rendered children of the element are cached. Subsequent calls to
+ * render() or RenderInterface::render() will not traverse the child tree of
+ * this element again: they will just use the cached children. So if you want to
+ * show an element, be sure to call show() on the element before its parent tree
+ * is rendered for the first time, as it will have no effect on subsequent
  * renderings of the parent tree.
  *
  * @param $element
@@ -457,6 +458,7 @@ function hide(&$element) {
  * @return
  *   The element.
  *
+ * @see \Drupal\Core\Render\RendererInterface
  * @see render()
  * @see hide()
  */

core/lib/Drupal/Core/Entity/EntityViewBuilder.php

@@ -246,8 +246,8 @@ class EntityViewBuilder extends EntityHandlerBase implements EntityHandlerInterf
    * This function is assigned as a #pre_render callback in ::viewMultiple().
    *
    * By delaying the building of an entity until the #pre_render processing in
-   * drupal_render(), the processing cost of assembling an entity's renderable
-   * array is saved on cache-hit requests.
+   * \Drupal::service('renderer')->render(), the processing cost of assembling
+   * an entity's renderable array is saved on cache-hit requests.
    *
    * @param array $build_list
    *   A renderable  array containing build information and context for an

core/lib/Drupal/Core/Entity/entity.api.php

@@ -1537,7 +1537,7 @@ function hook_ENTITY_TYPE_view(array &$build, \Drupal\Core\Entity\EntityInterfac
  * the particular entity type template, if there is one (e.g., node.html.twig).
  *
  * See the @link themeable Default theme implementations topic @endlink and
- * drupal_render() for details.
+ * \Drupal\Core\Render\RendererInterface::render() for details.
  *
  * @param array &$build
  *   A renderable array representing the entity content.
@@ -1576,7 +1576,7 @@ function hook_entity_view_alter(array &$build, \Drupal\Core\Entity\EntityInterfa
  * the particular entity type template, if there is one (e.g., node.html.twig).
  *
  * See the @link themeable Default theme implementations topic @endlink and
- * drupal_render() for details.
+ * \Drupal\Core\Render\RendererInterface::render() for details.
  *
  * @param array &$build
  *   A renderable array representing the entity content.
@@ -1659,7 +1659,7 @@ function hook_entity_view_mode_alter(&$view_mode, \Drupal\Core\Entity\EntityInte
 }
 
 /**
- * Alter entity renderable values before cache checking in drupal_render().
+ * Alter entity renderable values before cache checking during rendering.
  *
  * Invoked for a specific entity type.
  *
@@ -1685,7 +1685,7 @@ function hook_ENTITY_TYPE_build_defaults_alter(array &$build, \Drupal\Core\Entit
 }
 
 /**
- * Alter entity renderable values before cache checking in drupal_render().
+ * Alter entity renderable values before cache checking during rendering.
  *
  * The values in the #cache key of the renderable array are used to determine if
  * a cache entry exists for the entity's rendered output. Ideally only values

core/lib/Drupal/Core/EventSubscriber/EarlyRenderingControllerWrapperSubscriber.php

@@ -17,11 +17,11 @@ use Symfony\Component\HttpKernel\KernelEvents;
 /**
  * Subscriber that wraps controllers, to handle early rendering.
  *
- * When controllers call drupal_render() (RendererInterface::render()) outside
- * of a render context, we call that "early rendering". Controllers should
- * return only render arrays, but we cannot prevent controllers from doing early
- * rendering. The problem with early rendering is that the bubbleable metadata
- * (cacheability & attachments) are lost.
+ * When controllers call RendererInterface::render() outside of a render
+ * context, we call that "early rendering". Controllers should return
+ * only render arrays, but we cannot prevent controllers from doing
+ * early rendering. The problem with early rendering is that the
+ * bubbleable metadata (cacheability & attachments) are lost.
  *
  * This can lead to broken pages (missing assets), stale pages (missing cache
  * tags causing a page not to be invalidated) or even security problems (missing
@@ -36,8 +36,8 @@ use Symfony\Component\HttpKernel\KernelEvents;
  * ::renderPlain() methods. In that case, no bubbleable metadata is lost.
  *
  * If the render context is not empty, then the controller did use
- * drupal_render(), and bubbleable metadata was collected. This bubbleable
- * metadata is then merged onto the render array.
+ * RendererInterface::render(), and bubbleable metadata was collected.
+ * This bubbleable metadata is then merged onto the render array.
  *
  * In other words: this just exists to ease the transition to Drupal 8: it
  * allows controllers that return render arrays (the majority) and
@@ -124,8 +124,8 @@ class EarlyRenderingControllerWrapperSubscriber implements EventSubscriberInterf
     });
 
     // If early rendering happened, i.e. if code in the controller called
-    // drupal_render() outside of a render context, then the bubbleable metadata
-    // for that is stored in the current render context.
+    // RendererInterface::render() outside of a render context, then the
+    // bubbleable metadata for that is stored in the current render context.
     if (!$context->isEmpty()) {
       /** @var \Drupal\Core\Render\BubbleableMetadata $early_rendering_bubbleable_metadata */
       $early_rendering_bubbleable_metadata = $context->pop();

core/lib/Drupal/Core/Form/FormBuilderInterface.php

@@ -245,10 +245,11 @@ interface FormBuilderInterface {
    * This is one of the three primary functions that recursively iterates a form
    * array. This one does it for completing the form building process. The other
    * two are self::doValidateForm() (invoked via self::validateForm() and used
-   * to invoke validation logic for each element) and drupal_render() (for
-   * rendering each element). Each of these three pipelines provides ample
-   * opportunity for modules to customize what happens. For example, during this
-   * function's life cycle, the following functions get called for each element:
+   * to invoke validation logic for each element) and
+   * RendererInterface::render() (for rendering each element).
+   * Each of these three pipelines provides ample opportunity for modules to
+   * customize what happens. For example, during this function's life cycle,
+   * the following functions get called for each element:
    * - $element['#value_callback']: A callable that implements how user input is
    *   mapped to an element's #value property. This defaults to a function named
    *   'form_type_TYPE_value' where TYPE is $element['#type'].
@@ -269,8 +270,8 @@ interface FormBuilderInterface {
    *   called in postorder traversal, meaning they are called for the child
    *   elements first, then for the parent element.
    * There are similar properties containing callback functions invoked by
-   * self::doValidateForm() and drupal_render(), appropriate for those
-   * operations.
+   * self::doValidateForm() and RendererInterface::render(),
+   * appropriate for those operations.
    *
    * Developers are strongly encouraged to integrate the functionality needed by
    * their form or module within one of these three pipelines, using the

core/lib/Drupal/Core/Menu/MenuLinkTree.php

@@ -171,7 +171,8 @@ class MenuLinkTree implements MenuLinkTreeInterface {
     $tree_cacheability->applyTo($build);
 
     if ($items) {
-      // Make sure drupal_render() does not re-order the links.
+      // Make sure Drupal\Core\Render\Element::children() does not re-order the
+      // links.
       $build['#sorted'] = TRUE;
       // Get the menu name from the last link.
       $item = end($items);

core/lib/Drupal/Core/Render/Element.php

@@ -57,7 +57,8 @@ class Element {
    * Identifies the children of an element array, optionally sorted by weight.
    *
    * The children of an element array are those key/value pairs whose key does
-   * not start with a '#'. See drupal_render() for details.
+   * not start with a '#'. See \Drupal\Core\Render\RendererInterface::render()
+   * for details.
    *
    * @param array $elements
    *   The element array whose children are to be identified. Passed by

core/lib/Drupal/Core/Render/Element/HtmlTag.php

@@ -172,8 +172,8 @@ class HtmlTag extends RenderElement {
     // technique. See http://wikipedia.org/wiki/Conditional_comment
     // for details.
 
-    // Ensure what we are dealing with is safe.
-    // This would be done later anyway in drupal_render().
+    // Ensure what we are dealing with is safe. This would be done later anyway
+    // in \Drupal::service('renderer')->render().
     $prefix = isset($element['#prefix']) ? $element['#prefix'] : '';
     if ($prefix && !($prefix instanceof MarkupInterface)) {
       $prefix = Xss::filterAdmin($prefix);

core/lib/Drupal/Core/Render/Element/Link.php

@@ -111,9 +111,10 @@ class Link extends RenderElement {
    *
    * The purpose of this is to allow links to be logically grouped into related
    * categories, so that each child group can be rendered as its own list of
-   * links if drupal_render() is called on it, but calling drupal_render() on
-   * the parent element will still produce a single list containing all the
-   * remaining links, regardless of what group they were in.
+   * links if RendererInterface::render() is called on it, but
+   * calling RendererInterface::render() on the parent element will
+   * still produce a single list containing all the remaining links, regardless
+   * of what group they were in.
    *
    * A typical example comes from node links, which are stored in a renderable
    * array similar to this:

core/lib/Drupal/Core/Render/Renderer.php

@@ -548,7 +548,7 @@ class Renderer implements RendererInterface {
       $this->replacePlaceholders($elements);
       // @todo remove as part of https://www.drupal.org/node/2511330.
       if ($context->count() !== 1) {
-        throw new \LogicException('A stray drupal_render() invocation with $is_root_call = TRUE is causing bubbling of attached assets to break.');
+        throw new \LogicException('A stray RendererInterface::render() invocation with $is_root_call = TRUE is causing bubbling of attached assets to break.');
       }
     }
 

core/lib/Drupal/Core/Render/theme.api.php

@@ -17,11 +17,12 @@
  * hierarchical arrays that include the data to be rendered into HTML (or XML or
  * another output format), and options that affect the markup. Render arrays
  * are ultimately rendered into HTML or other output formats by recursive calls
- * to drupal_render(), traversing the depth of the render array hierarchy. At
- * each level, the theme system is invoked to do the actual rendering. See the
- * documentation of drupal_render() and the
- * @link theme_render Theme system and Render API topic @endlink for more
- * information about render arrays and rendering.
+ * to \Drupal\Core\Render\RendererInterface::render(), traversing the depth of
+ * the render array hierarchy. At each level, the theme system is invoked to do
+ * the actual rendering. See the documentation of
+ * \Drupal\Core\Render\RendererInterface::render() and the @link theme_render
+ * Theme system and Render API topic @endlink for more information about render
+ * arrays and rendering.
  *
  * @section sec_twig_theme Twig Templating Engine
  * Drupal 8 uses the templating engine Twig. Twig offers developers a fast,
@@ -241,13 +242,16 @@
  * hierarchical associative array containing data to be rendered and properties
  * describing how the data should be rendered. A render array that is returned
  * by a function to specify markup to be sent to the web browser or other
- * services will eventually be rendered by a call to drupal_render(), which will
- * recurse through the render array hierarchy if appropriate, making calls into
- * the theme system to do the actual rendering. If a function or method actually
- * needs to return rendered output rather than a render array, the best practice
- * would be to create a render array, render it by calling drupal_render(), and
- * return that result, rather than writing the markup directly. See the
- * documentation of drupal_render() for more details of the rendering process.
+ * services will eventually be rendered by a call to
+ * \Drupal\Core\Render\RendererInterface::render(), which will recurse through
+ * the render array hierarchy if appropriate, making calls into the theme system
+ * to do the actual rendering. If a function or method actually needs to return
+ * rendered output rather than a render array, the best practice would be to
+ * create a render array, render it by calling
+ * \Drupal\Core\Render\RendererInterface::render(), and return that result,
+ * rather than writing the markup directly. See the documentation of
+ * \Drupal\Core\Render\RendererInterface::render() for more details of the
+ * rendering process.
  *
  * Each level in the hierarchy of a render array (including the outermost array)
  * has one or more array elements. Array elements whose names start with '#' are

core/modules/block/block.api.php

@@ -72,8 +72,9 @@ use Drupal\Core\Access\AccessResult;
  * If the module wishes to act on the rendered HTML of the block rather than
  * the structured content array, it may use this hook to add a #post_render
  * callback. Alternatively, it could also implement hook_preprocess_HOOK() for
- * block.html.twig. See drupal_render() documentation or the
- * @link themeable Default theme implementations topic @endlink for details.
+ * block.html.twig. See \Drupal\Core\Render\RendererInterface::render()
+ * documentation or the @link themeable Default theme implementations topic
+ * @endlink for details.
  *
  * In addition to hook_block_view_alter(), which is called for all blocks, there
  * is hook_block_view_BASE_BLOCK_ID_alter(), which can be used to target a

core/modules/book/src/BookManager.php

@@ -596,7 +596,8 @@ class BookManager implements BookManagerInterface {
     $build = [];
 
     if ($items) {
-      // Make sure drupal_render() does not re-order the links.
+      // Make sure Drupal\Core\Render\Element::children() does not re-order the
+      // links.
       $build['#sorted'] = TRUE;
       // Get the book id from the last link.
       $item = end($items);

core/modules/contextual/src/Element/ContextualLinks.php

@@ -86,7 +86,8 @@ class ContextualLinks extends RenderElement {
     // Allow modules to alter the renderable contextual links element.
     static::moduleHandler()->alter('contextual_links_view', $element, $items);
 
-    // If there are no links, tell drupal_render() to abort rendering.
+    // If there are no links, tell \Drupal::service('renderer')->render() to
+    // abort rendering.
     if (empty($element['#links'])) {
       $element['#printed'] = TRUE;
     }

core/modules/image/tests/src/Functional/ImageDimensionsTest.php

@@ -296,11 +296,12 @@ class ImageDimensionsTest extends BrowserTestBase {
   /**
    * Render an image style element.
    *
-   * Function drupal_render() alters the passed $variables array by adding a new
-   * key '#printed' => TRUE. This prevents next call to re-render the element.
-   * We wrap drupal_render() in a helper protected method and pass each time a
-   * fresh array so that $variables won't get altered and the element is
-   * re-rendered each time.
+   * Function \Drupal\Core\Render\RendererInterface::render() alters the passed
+   * $variables array by adding a new key '#printed' => TRUE. This prevents next
+   * call to re-render the element. We wrap
+   * \Drupal\Core\Render\RendererInterface::render() in a helper protected
+   * method and pass each time a fresh array so that $variables won't get
+   * altered and the element is re-rendered each time.
    */
   protected function getImageTag($variables) {
     return str_replace("\n", NULL, \Drupal::service('renderer')->renderRoot($variables));

core/modules/system/tests/modules/theme_legacy_test/theme_legacy_test.module

@@ -63,12 +63,12 @@ function theme_theme_test_function_template_override($variables) {
 }
 
 /**
- * Theme function for testing rendering of child elements via drupal_render().
+ * Theme function for testing rendering of child elements.
  *
  * Theme hooks defining a 'render element' add an internal '#render_children'
- * property. When this property is found, drupal_render() avoids calling
- * the 'theme.manager' service 'render' method on the top-level element to
- * prevent infinite recursion.
+ * property. When this property is found, \Drupal::service('renderer')->render()
+ * avoids calling the 'theme.manager' service's ThemeManagerInterface::render()
+ * method on the top-level element to prevent infinite recursion.
  *
  * @param array $variables
  *   An associative array containing:

core/modules/system/tests/src/Functional/Common/RenderWebTest.php

@@ -8,7 +8,7 @@ use Drupal\Tests\BrowserTestBase;
 use Drupal\Tests\system\Functional\Cache\AssertPageCacheContextsAndTagsTrait;
 
 /**
- * Performs integration tests on drupal_render().
+ * Performs integration tests on \Drupal::service('renderer')->render().
  *
  * @group Common
  */

core/modules/system/tests/src/Kernel/Common/FormElementsRenderTest.php

@@ -7,7 +7,7 @@ use Drupal\Core\Url;
 use Drupal\KernelTests\KernelTestBase;
 
 /**
- * Performs integration tests on drupal_render().
+ * Performs integration tests on \Drupal::service('renderer')->render().
  *
  * @group system
  */

core/modules/system/tests/src/Kernel/Theme/ThemeTest.php

@@ -135,7 +135,7 @@ class ThemeTest extends KernelTestBase {
         '#markup' => 'Foo',
       ],
     ];
-    $this->assertThemeOutput('theme_test_render_element_children', $element, 'Foo', 'drupal_render() avoids #theme recursion loop when rendering a render element.');
+    $this->assertThemeOutput('theme_test_render_element_children', $element, 'Foo', "\Drupal::service('renderer')->render() avoids #theme recursion loop when rendering a render element.");
 
     $element = [
       '#theme_wrappers' => ['theme_test_render_element_children'],
@@ -143,7 +143,7 @@ class ThemeTest extends KernelTestBase {
         '#markup' => 'Foo',
       ],
     ];
-    $this->assertThemeOutput('theme_test_render_element_children', $element, 'Foo', 'drupal_render() avoids #theme_wrappers recursion loop when rendering a render element.');
+    $this->assertThemeOutput('theme_test_render_element_children', $element, 'Foo', "\Drupal::service('renderer')->render() avoids #theme_wrappers recursion loop when rendering a render element.");
   }
 
   /**

core/modules/toolbar/src/Element/Toolbar.php

@@ -50,7 +50,7 @@ class Toolbar extends RenderElement {
   }
 
   /**
-   * Builds the Toolbar as a structured array ready for drupal_render().
+   * Builds the Toolbar as a structured array ready for rendering.
    *
    * Since building the toolbar takes some time, it is done just prior to
    * rendering to ensure that it is built only if it will be displayed.

core/modules/views/src/Plugin/views/field/FieldHandlerInterface.php

@@ -255,7 +255,7 @@ interface FieldHandlerInterface extends ViewsHandlerInterface {
   public function getRenderTokens($item);
 
   /**
-   * Passes values to drupal_render() using $this->themeFunctions() as #theme.
+   * Renders row values using $this->themeFunctions() as #theme.
    *
    * @param \Drupal\views\ResultRow $values
    *   Holds single row of a view's result set.

core/tests/Drupal/KernelTests/Core/Entity/EntityViewBuilderTest.php

@@ -45,7 +45,7 @@ class EntityViewBuilderTest extends EntityKernelTestBase {
     $cache_contexts_manager = \Drupal::service("cache_contexts_manager");
     $cache = \Drupal::cache();
 
-    // Force a request via GET so we can get drupal_render() cache working.
+    // Force a request via GET so cache is rendered.
     $request = \Drupal::request();
     $request_method = $request->server->get('REQUEST_METHOD');
     $request->setMethod('GET');
@@ -99,7 +99,8 @@ class EntityViewBuilderTest extends EntityKernelTestBase {
     $renderer = $this->container->get('renderer');
     $cache_contexts_manager = \Drupal::service("cache_contexts_manager");
 
-    // Force a request via GET so we can get drupal_render() cache working.
+    // Force a request via GET so we can get
+    // \Drupal::service('renderer')->render() cache working.
     $request = \Drupal::request();
     $request_method = $request->server->get('REQUEST_METHOD');
     $request->setMethod('GET');

core/tests/Drupal/KernelTests/Core/Render/Element/RenderElementTypesTest.php

@@ -7,7 +7,7 @@ use Drupal\Core\Url;
 use Drupal\KernelTests\KernelTestBase;
 
 /**
- * Tests the markup of core render element types passed to drupal_render().
+ * Tests the rendered markup of core render element types.
  *
  * @group Common
  */
@@ -182,7 +182,7 @@ class RenderElementTypesTest extends KernelTestBase {
     foreach ($elements as $element) {
       $xml = new \SimpleXMLElement(\Drupal::service('renderer')->renderRoot($element['value']));
       $result = $xml->xpath($element['expected']);
-      $this->assertNotEmpty($result, '"' . $element['name'] . '" input rendered correctly by drupal_render().');
+      $this->assertNotEmpty($result, '"' . $element['name'] . '" input rendered correctly.');
     }
   }
 
@@ -213,7 +213,7 @@ class RenderElementTypesTest extends KernelTestBase {
     foreach ($elements as $element) {
       $xml = new \SimpleXMLElement(\Drupal::service('renderer')->renderRoot($element['value']));
       $result = $xml->xpath($element['expected']);
-      $this->assertNotEmpty($result, '"' . $element['name'] . '" is rendered correctly by drupal_render().');
+      $this->assertNotEmpty($result, '"' . $element['name'] . '" is rendered correctly.');
     }
 
     // Set admin compact mode on for additional tests.
@@ -229,7 +229,7 @@ class RenderElementTypesTest extends KernelTestBase {
 
     $xml = new \SimpleXMLElement(\Drupal::service('renderer')->renderRoot($element['value']));
     $result = $xml->xpath($element['expected']);
-    $this->assertNotEmpty($result, '"' . $element['name'] . '" is rendered correctly by drupal_render().');
+    $this->assertNotEmpty($result, '"' . $element['name'] . '" is rendered correctly.');
   }
 
 }

core/tests/Drupal/KernelTests/Core/Render/RenderTest.php

@@ -5,7 +5,7 @@ namespace Drupal\KernelTests\Core\Render;
 use Drupal\KernelTests\KernelTestBase;
 
 /**
- * Performs functional tests on drupal_render().
+ * Performs functional tests on \Drupal::service('renderer')->render().
  *
  * @group Common
  */

core/tests/Drupal/Tests/Core/Render/RendererTest.php

@@ -507,8 +507,9 @@ class RendererTest extends RendererTestBase {
     $this->assertTrue($elements['#sorted'], "'#sorted' => TRUE was added to the array");
 
     // Pass $elements through \Drupal\Core\Render\Element::children() and
-    // ensure it remains sorted in the correct order. drupal_render() will
-    // return an empty string if used on the same array in the same request.
+    // ensure it remains sorted in the correct order.
+    // \Drupal::service('renderer')->render() will return an empty string if
+    // used on the same array in the same request.
     $children = Element::children($elements);
     $this->assertSame('first', array_shift($children), 'Child found in the correct order.');
     $this->assertSame('second', array_shift($children), 'Child found in the correct order.');

core/tests/Drupal/Tests/EntityViewTrait.php

@@ -15,11 +15,11 @@ trait EntityViewTrait {
    *
    * Entities postpone the composition of their renderable arrays to #pre_render
    * functions in order to maximize cache efficacy. This means that the full
-   * renderable array for an entity is constructed in drupal_render(). Some
-   * tests require the complete renderable array for an entity outside of the
-   * drupal_render process in order to verify the presence of specific values.
-   * This method isolates the steps in the render process that produce an
-   * entity's renderable array.
+   * renderable array for an entity is constructed in
+   * \Drupal::service('renderer')->render(). Some tests require the complete
+   * renderable array for an entity outside of the render process in order to
+   * verify the presence of specific values. This method isolates the steps in
+   * the render process that produce an entity's renderable array.
    *
    * @param \Drupal\Core\Entity\EntityInterface $entity
    *   The entity to prepare a renderable array for.

core/themes/claro/claro.theme

@@ -42,9 +42,8 @@ function claro_theme_suggestions_details_alter(&$suggestions, $variables) {
 /**
  * Implements hook_preprocess_HOOK() for menu-local-tasks templates.
  *
- * Use preprocess hook to set #attached to child elements
- * because they will be processed by Twig and drupal_render will
- * be invoked.
+ * Use preprocess hook to set #attached to child elements because they will be
+ * processed by Twig and \Drupal::service('renderer')->render() will be invoked.
  */
 function claro_preprocess_menu_local_tasks(&$variables) {
   if (!empty($variables['primary'])) {

core/themes/seven/seven.theme

@@ -30,9 +30,8 @@ function seven_preprocess_html(&$variables) {
 /**
  * Implements hook_preprocess_HOOK() for menu-local-tasks templates.
  *
- * Use preprocess hook to set #attached to child elements
- * because they will be processed by Twig and drupal_render will
- * be invoked.
+ * Use preprocess hook to set #attached to child elements because they will be
+ * processed by Twig and \Drupal::service('renderer')->render() will be invoked.
  */
 function seven_preprocess_menu_local_tasks(&$variables) {
   if (!empty($variables['primary'])) {