diff --git a/core/modules/views/lib/Drupal/views/Tests/Handler/FieldUnitTest.php b/core/modules/views/lib/Drupal/views/Tests/Handler/FieldUnitTest.php
index 7e21ec2..2624923 100644
--- a/core/modules/views/lib/Drupal/views/Tests/Handler/FieldUnitTest.php
+++ b/core/modules/views/lib/Drupal/views/Tests/Handler/FieldUnitTest.php
@@ -85,16 +85,22 @@ public function testQuery() {
   }
 
   /**
-   * Assertion helper which checks whether a string is part of another string.
+   * Asserts that a string is part of another string.
    *
    * @param string $haystack
    *   The value to search in.
    * @param string $needle
    *   The value to search for.
    * @param string $message
-   *   The message to display along with the assertion.
+   *   (optional) A message to display with the assertion. Do not translate
+   *   messages: use format_string() to embed variables in the message text, not
+   *   t(). If left blank, a default message will be displayed.
    * @param string $group
-   *   The type of assertion - examples are "Browser", "PHP".
+   *   (optional) The group this message is in, which is displayed in a column
+   *   in test output. Use 'Debug' to indicate this is debugging output. Do not
+   *   translate this string. Defaults to 'Other'; most tests do not override
+   *   this default.
+   *
    * @return bool
    *   TRUE if the assertion succeeded, FALSE otherwise.
    */
@@ -103,16 +109,22 @@ protected function assertSubString($haystack, $needle, $message = '', $group = '
   }
 
   /**
-   * Assertion helper which checks whether a string is not part of another string.
+   * Asserts that a string is not part of another string.
    *
    * @param string $haystack
    *   The value to search in.
    * @param string $needle
    *   The value to search for.
    * @param string $message
-   *   The message to display along with the assertion.
+   *   (optional) A message to display with the assertion. Do not translate
+   *   messages: use format_string() to embed variables in the message text, not
+   *   t(). If left blank, a default message will be displayed.
    * @param string $group
-   *   The type of assertion - examples are "Browser", "PHP".
+   *   (optional) The group this message is in, which is displayed in a column
+   *   in test output. Use 'Debug' to indicate this is debugging output. Do not
+   *   translate this string. Defaults to 'Other'; most tests do not override
+   *   this default.
+   *
    * @return bool
    *   TRUE if the assertion succeeded, FALSE otherwise.
    */
diff --git a/core/modules/views/lib/Drupal/views/Tests/ViewTestBase.php b/core/modules/views/lib/Drupal/views/Tests/ViewTestBase.php
index 02c86f5..d477524 100644
--- a/core/modules/views/lib/Drupal/views/Tests/ViewTestBase.php
+++ b/core/modules/views/lib/Drupal/views/Tests/ViewTestBase.php
@@ -1,7 +1,8 @@
 <?php
+
 /**
  * @file
- * Definition of Drupal\views\Tests\ViewTestBase.
+ * Contains \Drupal\views\Tests\ViewTestBase.
  */
 
 namespace Drupal\views\Tests;
@@ -9,7 +10,14 @@
 use Drupal\simpletest\WebTestBase;
 
 /**
- * Abstract class for views testing.
+ * Defines a base class for Views testing in the full web test environment.
+ *
+ * Use this base test class if you need to emulate a full Drupal installation.
+ * When possible, ViewUnitTestBase should be used instead. Both base classes
+ * include the same methods.
+ *
+ * @see \Drupal\views\Tests\ViewUnitTestBase
+ * @see \Drupal\simpletest\WebTestBase
  */
 abstract class ViewTestBase extends WebTestBase {
 
@@ -36,8 +44,8 @@ protected function setUp() {
   /**
    * Sets up the views_test_data.module.
    *
-   * Because the schema of views_test_data.module is dependent on the test using it,
-   * it cannot be enabled normally.
+   * Because the schema of views_test_data.module is dependent on the test
+   * using it, it cannot be enabled normally.
    */
   protected function enableViewsTestModule() {
     // Define the schema and views data variable before enabling the test module.
@@ -62,41 +70,78 @@ protected function enableViewsTestModule() {
   }
 
   /**
-   * Helper function: verify a result set returned by view.
+   * Verifies that a result set returned by a View matches expected values.
    *
    * The comparison is done on the string representation of the columns of the
    * column map, taking the order of the rows into account, but not the order
    * of the columns.
    *
-   * @param $view
-   *  An executed View.
-   * @param $expected_result
-   *  An expected result set.
-   * @param $column_map
-   *  An associative array mapping the columns of the result set from the view
-   *  (as keys) and the expected result set (as values).
+   * @param \Drupal\views\ViewExecutable $view
+   *   An executed View.
+   * @param array $expected_result
+   *   An expected result set.
+   * @param array $column_map
+   *   (optional) An associative array mapping the columns of the result set
+   *   from the view (as keys) and the expected result set (as values).
+   * @param string $message
+   *   (optional) A custom message to display with the assertion. Defaults to
+   *   'Identical result set.'
+   *
+   * @return bool
+   *   TRUE if the assertion succeeded, or FALSE otherwise.
    */
-  protected function assertIdenticalResultset($view, $expected_result, $column_map = array(), $message = 'Identical result set') {
+  protected function assertIdenticalResultset($view, $expected_result, $column_map = array(), $message = 'Identical result set.') {
     return $this->assertIdenticalResultsetHelper($view, $expected_result, $column_map, $message, 'assertIdentical');
   }
 
   /**
-   * Helper function: verify a result set returned by view..
+   * Verifies that a result set returned by a View differs from certain values.
    *
    * Inverse of ViewsTestCase::assertIdenticalResultset().
    *
-   * @param $view
-   *  An executed View.
-   * @param $expected_result
-   *  An expected result set.
-   * @param $column_map
-   *  An associative array mapping the columns of the result set from the view
-   *  (as keys) and the expected result set (as values).
+   * @param \Drupal\views\ViewExecutable $view
+   *   An executed View.
+   * @param array $expected_result
+   *   An expected result set.
+   * @param array $column_map
+   *   (optional) An associative array mapping the columns of the result set
+   *  from the view (as keys) and the expected result set (as values).
+   * @param string $message
+   *   (optional) A custom message to display with the assertion. Defaults to
+   *   'Non-identical result set.'
+   *
+   * @return bool
+   *   TRUE if the assertion succeeded, or FALSE otherwise.
    */
-  protected function assertNotIdenticalResultset($view, $expected_result, $column_map = array(), $message = 'Identical result set') {
+  protected function assertNotIdenticalResultset($view, $expected_result, $column_map = array(), $message = 'Non-identical result set.') {
     return $this->assertIdenticalResultsetHelper($view, $expected_result, $column_map, $message, 'assertNotIdentical');
   }
 
+  /**
+   * Performs View result assertions.
+   *
+   * This is a helper method for ViewTestBase::assertIdenticalResultset() and
+   * ViewTestBase::assertNotIdenticalResultset().
+   *
+   * @param \Drupal\views\ViewExecutable $view
+   *   An executed View.
+   * @param array $expected_result
+   *   An expected result set.
+   * @param array $column_map
+   *   An associative array mapping the columns of the result set
+   *   from the view (as keys) and the expected result set (as values).
+   * @param string $message
+   *   The message to display with the assertion.
+   * @param string $assert_method
+   *   The TestBase assertion method to use (either 'assertIdentical' or
+   *   'assertNotIdentical').
+   *
+   * @return bool
+   *   TRUE if the assertion succeeded, or FALSE otherwise.
+   *
+   * @see \Drupal\views\Tests\ViewTestBase::assertIdenticalResultset()
+   * @see \Drupal\views\Tests\ViewTestBase::assertNotIdenticalResultset()
+   */
   protected function assertIdenticalResultsetHelper($view, $expected_result, $column_map, $message, $assert_method) {
     // Convert $view->result to an array of arrays.
     $result = array();
@@ -130,7 +175,19 @@ protected function assertIdenticalResultsetHelper($view, $expected_result, $colu
   }
 
   /**
-   * Helper function: order an array of array based on a column.
+   * Orders a nested array containing a result set based on a given column.
+   *
+   * @param array $result_set
+   *   An array of rows from a result set, with each row as an associative
+   *   array keyed by column name.
+   * @param string $column
+   *   The column name by which to sort the result set.
+   * @param bool $reverse
+   *   (optional) Boolean indicating whether to sort the result set in reverse
+   *   order. Defaults to FALSE.
+   *
+   * @return array
+   *   The sorted result set.
    */
   protected function orderResultSet($result_set, $column, $reverse = FALSE) {
     $order = $reverse ? -1 : 1;
@@ -144,17 +201,30 @@ protected function orderResultSet($result_set, $column, $reverse = FALSE) {
   }
 
   /**
-   * Helper function to check whether a button with a certain id exists and has a certain label.
+   * Asserts the existence of a button with a certain ID and label.
+   *
+   * @param string $id
+   *   The HTML ID of the button
+   * @param string $label.
+   *   The expected label for the button.
+   * @param string $message
+   *   (optional) A custom message to display with the assertion. If no custom
+   *   message is provided, the message will indicate the button label.
+   *
+   * @return bool
+   *   TRUE if the asserion was succesful, or FALSE on failure.
    */
   protected function helperButtonHasLabel($id, $expected_label, $message = 'Label has the expected value: %label.') {
     return $this->assertFieldById($id, $expected_label, t($message, array('%label' => $expected_label)));
   }
 
   /**
-   * Helper function to execute a view with debugging.
+   * Executes a view with debugging.
    *
-   * @param view $view
+   * @param \Drupal\views\ViewExecutable $view
+   *   The view object.
    * @param array $args
+   *   (optional) An array of the view arguments to use for the view.
    */
   protected function executeView($view, $args = array()) {
     $view->setDisplay();
@@ -164,37 +234,38 @@ protected function executeView($view, $args = array()) {
   }
 
   /**
-   * The schema definition.
+   * Returns the schema definition.
    */
   protected function schemaDefinition() {
     return ViewTestData::schemaDefinition();
   }
 
   /**
-   * The views data definition.
+   * Returns the views data definition.
    */
   protected function viewsData() {
     return ViewTestData::viewsData();
   }
 
   /**
-   * A very simple test dataset.
+   * Returns a very simple test dataset.
    */
   protected function dataSet() {
     return ViewTestData::dataSet();
   }
 
   /**
-   * Build and return a basic view of the views_test_data table.
+   * Builds and returns a basic view of the views_test_data table.
    *
    * @return Drupal\views\ViewExecutable
+   *   The built view object.
    */
   protected function getBasicView() {
     return $this->createViewFromConfig('test_view');
   }
 
   /**
-   * Creates a new View instance by creating directly from config data.
+   * Creates a new View instance by creating it directly from config data.
    *
    * @param string $view_name
    *   The name of the test view to create.
diff --git a/core/modules/views/lib/Drupal/views/Tests/ViewTestData.php b/core/modules/views/lib/Drupal/views/Tests/ViewTestData.php
index efd9f5a..6a2d87c 100644
--- a/core/modules/views/lib/Drupal/views/Tests/ViewTestData.php
+++ b/core/modules/views/lib/Drupal/views/Tests/ViewTestData.php
@@ -8,7 +8,7 @@
 namespace Drupal\views\Tests;
 
 /**
- * A class which contains the base schema, example and views data for tests.
+ * Provides tests view data and the base test schema with sample data records.
  *
  * The methods will be used by both views test base classes.
  *
@@ -18,7 +18,7 @@
 class ViewTestData {
 
   /**
-   * The schema definition.
+   * Returns the schema definition.
    */
   public static function schemaDefinition() {
     $schema['views_test_data'] = array(
@@ -69,7 +69,7 @@ public static function schemaDefinition() {
   }
 
   /**
-   * The views data definition.
+   * Returns the views data definition.
    */
   public static function viewsData() {
     // Declaration of the base table.
@@ -172,7 +172,7 @@ public static function viewsData() {
   }
 
   /**
-   * A very simple test dataset.
+   * Returns a very simple test dataset.
    */
   public static function dataSet() {
     return array(
@@ -208,5 +208,6 @@ public static function dataSet() {
       ),
     );
   }
+
 }
 
diff --git a/core/modules/views/lib/Drupal/views/Tests/ViewUnitTestBase.php b/core/modules/views/lib/Drupal/views/Tests/ViewUnitTestBase.php
index 0151123..6cec8db 100644
--- a/core/modules/views/lib/Drupal/views/Tests/ViewUnitTestBase.php
+++ b/core/modules/views/lib/Drupal/views/Tests/ViewUnitTestBase.php
@@ -13,7 +13,14 @@
 use Symfony\Component\HttpFoundation\Request;
 
 /**
- * Abstract class for views testing.
+ * Defines a base class for Views unit testing.
+ *
+ * Use this test class for unit tests of Views functionality. If a test
+ * requires the full web test environment provided by WebTestBase, extend
+ * ViewTestBase instead.
+ *
+ * @see \Drupal\views\Tests\ViewTestBase
+ * @see \Drupal\simpletest\DrupalUnitTestBase
  */
 abstract class ViewUnitTestBase extends DrupalUnitTestBase {
 
@@ -36,42 +43,80 @@ protected function setUp() {
     $query->execute();
   }
 
+
   /**
-   * Helper function: verify a result set returned by view.
+   * Verifies that a result set returned by a View matches expected values.
    *
    * The comparison is done on the string representation of the columns of the
    * column map, taking the order of the rows into account, but not the order
    * of the columns.
    *
-   * @param $view
-   *  An executed View.
-   * @param $expected_result
-   *  An expected result set.
-   * @param $column_map
-   *  An associative array mapping the columns of the result set from the view
-   *  (as keys) and the expected result set (as values).
+   * @param \Drupal\views\ViewExecutable $view
+   *   An executed View.
+   * @param array $expected_result
+   *   An expected result set.
+   * @param array $column_map
+   *   (optional) An associative array mapping the columns of the result set
+   *   from the view (as keys) and the expected result set (as values).
+   * @param string $message
+   *   (optional) A custom message to display with the assertion. Defaults to
+   *   'Identical result set.'
+   *
+   * @return bool
+   *   TRUE if the assertion succeeded, or FALSE otherwise.
    */
   protected function assertIdenticalResultset($view, $expected_result, $column_map = array(), $message = 'Identical result set') {
     return $this->assertIdenticalResultsetHelper($view, $expected_result, $column_map, $message, 'assertIdentical');
   }
 
   /**
-   * Helper function: verify a result set returned by view..
+   * Verifies that a result set returned by a View differs from certain values.
    *
    * Inverse of ViewsTestCase::assertIdenticalResultset().
    *
-   * @param $view
-   *  An executed View.
-   * @param $expected_result
-   *  An expected result set.
-   * @param $column_map
-   *  An associative array mapping the columns of the result set from the view
-   *  (as keys) and the expected result set (as values).
+   * @param \Drupal\views\ViewExecutable $view
+   *   An executed View.
+   * @param array $expected_result
+   *   An expected result set.
+   * @param array $column_map
+   *   (optional) An associative array mapping the columns of the result set
+   *  from the view (as keys) and the expected result set (as values).
+   * @param string $message
+   *   (optional) A custom message to display with the assertion. Defaults to
+   *   'Non-identical result set.'
+   *
+   * @return bool
+   *   TRUE if the assertion succeeded, or FALSE otherwise.
    */
   protected function assertNotIdenticalResultset($view, $expected_result, $column_map = array(), $message = 'Identical result set') {
     return $this->assertIdenticalResultsetHelper($view, $expected_result, $column_map, $message, 'assertNotIdentical');
   }
 
+  /**
+   * Performs View result assertions.
+   *
+   * This is a helper method for ViewTestBase::assertIdenticalResultset() and
+   * ViewTestBase::assertNotIdenticalResultset().
+   *
+   * @param \Drupal\views\ViewExecutable $view
+   *   An executed View.
+   * @param array $expected_result
+   *   An expected result set.
+   * @param array $column_map
+   *   An associative array mapping the columns of the result set
+   *   from the view (as keys) and the expected result set (as values).
+   * @param string $message
+   *   The message to display with the assertion.
+   * @param string $assert_method
+   *   The TestBase assertion method to use (either 'assertIdentical' or
+   *   'assertNotIdentical').
+   *
+   * @return bool
+   *   TRUE if the assertion succeeded, or FALSE otherwise.
+   *
+   * @see \Drupal\views\Tests\ViewTestBase::assertIdenticalResultset()
+   * @see \Drupal\views\Tests\ViewTestBase::assertNotIdenticalResultset()
+   */
   protected function assertIdenticalResultsetHelper($view, $expected_result, $column_map, $message, $assert_method) {
     // Convert $view->result to an array of arrays.
     $result = array();
@@ -105,7 +150,19 @@ protected function assertIdenticalResultsetHelper($view, $expected_result, $colu
   }
 
   /**
-   * Helper function: order an array of array based on a column.
+   * Orders a nested array containing a result set based on a given column.
+   *
+   * @param array $result_set
+   *   An array of rows from a result set, with each row as an associative
+   *   array keyed by column name.
+   * @param string $column
+   *   The column name by which to sort the result set.
+   * @param bool $reverse
+   *   (optional) Boolean indicating whether to sort the result set in reverse
+   *   order. Defaults to FALSE.
+   *
+   * @return array
+   *   The sorted result set.
    */
   protected function orderResultSet($result_set, $column, $reverse = FALSE) {
     $order = $reverse ? -1 : 1;
@@ -119,10 +176,12 @@ protected function orderResultSet($result_set, $column, $reverse = FALSE) {
   }
 
   /**
-   * Helper function to execute a view with debugging.
+   * Executes a view with debugging.
    *
-   * @param view $view
+   * @param \Drupal\views\ViewExecutable $view
+   *   The view object.
    * @param array $args
+   *   (optional) An array of the view arguments to use for the view.
    */
   protected function executeView($view, $args = array()) {
     $view->setDisplay();
@@ -132,21 +191,21 @@ protected function executeView($view, $args = array()) {
   }
 
   /**
-   * The schema definition.
+   * Returns the schema definition.
    */
   protected function schemaDefinition() {
     return ViewTestData::schemaDefinition();
   }
 
   /**
-   * The views data definition.
+   * Returns the views data definition.
    */
   protected function viewsData() {
     return ViewTestData::viewsData();
   }
 
   /**
-   * A very simple test dataset.
+   * Returns a very simple test dataset.
    */
   protected function dataSet() {
     return ViewTestData::dataSet();