diff --git a/core/tests/Drupal/Tests/Core/Database/ConnectionTest.php b/core/tests/Drupal/Tests/Core/Database/ConnectionTest.php
index c1b65cb..20667ee 100644
--- a/core/tests/Drupal/Tests/Core/Database/ConnectionTest.php
+++ b/core/tests/Drupal/Tests/Core/Database/ConnectionTest.php
@@ -2,7 +2,7 @@
 
 /**
  * @file
- * Contains Drupal\system\Tests\Database\ConnectionTest.
+ * Contains Drupal\Tests\Core\Database\ConnectionTest.
  */
 
 namespace Drupal\Tests\Core\Database;
@@ -39,12 +39,12 @@ public static function getInfo() {
    *   - Expected result from Connection::tablePrefix().
    */
   public function providerPrefixRoundTrip() {
-    return array (
-      array (
-        array( '' => 'test_' ),
+    return array(
+      array(
+        array('' => 'test_'),
         'test_',
       ),
-      array (
+      array(
         array(
           'fooTable' => 'foo_',
           'barTable' => 'bar_',
@@ -62,19 +62,19 @@ public function providerPrefixRoundTrip() {
    *
    * @dataProvider providerPrefixRoundTrip
    */
-  public function testPrefixRoundTrip($expected, $prefixInfo) {
-    $mockPDO = $this->getMock('Drupal\Tests\Core\Database\Stub\StubPDO');
-    $connection = new StubConnection($mockPDO, array());
+  public function testPrefixRoundTrip($expected, $prefix_info) {
+    $mock_pdo = $this->getMock('Drupal\Tests\Core\Database\Stub\StubPDO');
+    $connection = new StubConnection($mock_pdo, array());
 
     // setPrefix() is protected, so we make it accessible with reflection.
     $reflection = new \ReflectionClass('Drupal\Tests\Core\Database\Stub\StubConnection');
-    $setPrefix = $reflection->getMethod('setPrefix');
-    $setPrefix->setAccessible(TRUE);
+    $set_prefix = $reflection->getMethod('setPrefix');
+    $set_prefix->setAccessible(TRUE);
 
     // Set the prefix data.
-    $setPrefix->invokeArgs($connection, array($prefixInfo));
+    $set_prefix->invokeArgs($connection, array($prefix_info));
     // Check the round-trip.
-    foreach ($expected as $table=>$prefix) {
+    foreach ($expected as $table => $prefix) {
       $this->assertEquals($prefix, $connection->tablePrefix($table));
     }
   }
@@ -89,15 +89,15 @@ public function testPrefixRoundTrip($expected, $prefixInfo) {
    *   - Query to be prefixed.
    */
   public function providerTestPrefixTables() {
-    return array (
-      array (
+    return array(
+      array(
         'SELECT * FROM test_table',
         'test_',
         'SELECT * FROM {table}',
       ),
-      array (
+      array(
         'SELECT * FROM first_table JOIN second_thingie',
-        array (
+        array(
           'table' => 'first_',
           'thingie' => 'second_',
         ),
@@ -111,9 +111,9 @@ public function providerTestPrefixTables() {
    *
    * @dataProvider providerTestPrefixTables
    */
-  public function testPrefixTables($expected, $prefixInfo, $query) {
-    $mockPDO = $this->getMock('Drupal\Tests\Core\Database\Stub\StubPDO');
-    $connection = new StubConnection($mockPDO, array('prefix' => $prefixInfo));
+  public function testPrefixTables($expected, $prefix_info, $query) {
+    $mock_pdo = $this->getMock('Drupal\Tests\Core\Database\Stub\StubPDO');
+    $connection = new StubConnection($mock_pdo, array('prefix' => $prefix_info));
     $this->assertEquals($expected, $connection->prefixTables($query));
   }
 
@@ -126,13 +126,13 @@ public function testPrefixTables($expected, $prefixInfo, $query) {
    *   - String to escape.
    */
   public function providerEscapeMethods() {
-    return array (
-      array ('thing', 'thing'),
-      array ('_item', '_item'),
-      array ('item_', 'item_'),
-      array ('_item_', '_item_'),
-      array ('', '!@#$%^&*()-=+'),
-      array ('123', '!1@2#3'),
+    return array(
+      array('thing', 'thing'),
+      array('_item', '_item'),
+      array('item_', 'item_'),
+      array('_item_', '_item_'),
+      array('', '!@#$%^&*()-=+'),
+      array('123', '!1@2#3'),
     );
   }
 
@@ -146,8 +146,8 @@ public function providerEscapeMethods() {
    * @todo Separate test method for each escape method?
    */
   public function testEscapeMethods($expected, $name) {
-    $mockPDO = $this->getMock('Drupal\Tests\Core\Database\Stub\StubPDO');
-    $connection = new StubConnection($mockPDO, array());
+    $mock_pdo = $this->getMock('Drupal\Tests\Core\Database\Stub\StubPDO');
+    $connection = new StubConnection($mock_pdo, array());
     $this->assertEquals($expected, $connection->escapeDatabase($name));
     $this->assertEquals($expected, $connection->escapeTable($name));
     $this->assertEquals($expected, $connection->escapeField($name));
@@ -165,7 +165,7 @@ public function testEscapeMethods($expected, $name) {
    *   - Class name without namespace.
    */
   public function providerGetDriverClass() {
-    return array (
+    return array(
       array(
         'nonexistent_class',
         'stub',
@@ -193,8 +193,8 @@ public function providerGetDriverClass() {
    * @dataProvider providerGetDriverClass
    */
   public function testGetDriverClass($expected, $driver, $namespace, $class) {
-    $mockPDO = $this->getMock('Drupal\Tests\Core\Database\Stub\StubPDO');
-    $connection = new StubConnection($mockPDO, array('namespace' => $namespace));
+    $mock_pdo = $this->getMock('Drupal\Tests\Core\Database\Stub\StubPDO');
+    $connection = new StubConnection($mock_pdo, array('namespace' => $namespace));
     // Set the driver using our stub class' public property.
     $connection->driver = $driver;
     $this->assertEquals($expected, $connection->getDriverClass($class));
@@ -210,7 +210,7 @@ public function testGetDriverClass($expected, $driver, $namespace, $class) {
    *   - Namespace for connection.
    */
   public function providerSchema() {
-    return array (
+    return array(
       array(
         'Drupal\\Tests\\Core\\Database\\Stub\\Driver\\Schema',
         'stub',
@@ -225,8 +225,8 @@ public function providerSchema() {
    * @dataProvider providerSchema
    */
   public function testSchema($expected, $driver, $namespace) {
-    $mockPDO = $this->getMock('Drupal\Tests\Core\Database\Stub\StubPDO');
-    $connection = new StubConnection($mockPDO, array('namespace' => $namespace));
+    $mock_pdo = $this->getMock('Drupal\Tests\Core\Database\Stub\StubPDO');
+    $connection = new StubConnection($mock_pdo, array('namespace' => $namespace));
     $connection->driver = $driver;
     $this->assertInstanceOf($expected, $connection->schema());
   }
@@ -235,12 +235,12 @@ public function testSchema($expected, $driver, $namespace) {
    * Test Connection::destroy().
    */
   public function testDestroy() {
-    $mockPDO = $this->getMock('Drupal\Tests\Core\Database\Stub\StubPDO');
+    $mock_pdo = $this->getMock('Drupal\Tests\Core\Database\Stub\StubPDO');
     // Mocking StubConnection gives us access to the $schema attribute.
     $connection = $this->getMock(
       'Drupal\Tests\Core\Database\Stub\StubConnection',
       NULL,
-      array($mockPDO, array('namespace' => 'Drupal\\Tests\\Core\\Database\\Stub\\Driver'))
+      array($mock_pdo, array('namespace' => 'Drupal\\Tests\\Core\\Database\\Stub\\Driver'))
     );
     // Generate a schema object in order to verify that we've NULLed it later.
     $this->assertInstanceOf(
@@ -261,9 +261,18 @@ public function testDestroy() {
    */
   public function providerMakeComments() {
     return array(
-      array ('/*  */ ', array ('')),
-      array ('/* Exploit * / DROP TABLE node; -- */ ', array('Exploit * / DROP TABLE node; --')),
-      array ('/* Exploit DROP TABLE node; --; another comment */ ', array('Exploit */ DROP TABLE node; --', 'another comment')),
+      array(
+        '/*  */ ',
+        array(''),
+      ),
+      array(
+        '/* Exploit * / DROP TABLE node; -- */ ',
+        array('Exploit * / DROP TABLE node; --'),
+      ),
+      array(
+        '/* Exploit DROP TABLE node; --; another comment */ ',
+        array('Exploit */ DROP TABLE node; --', 'another comment'),
+      ),
     );
   }
 
@@ -272,10 +281,10 @@ public function providerMakeComments() {
    *
    * @dataProvider providerMakeComments
    */
-  public function testMakeComments($expected, $commentArray) {
-    $mockPDO = $this->getMock('Drupal\Tests\Core\Database\Stub\StubPDO');
-    $connection = new StubConnection($mockPDO, array());
-    $this->assertEquals($expected, $connection->makeComment($commentArray));
+  public function testMakeComments($expected, $comment_array) {
+    $mock_pdo = $this->getMock('Drupal\Tests\Core\Database\Stub\StubPDO');
+    $connection = new StubConnection($mock_pdo, array());
+    $this->assertEquals($expected, $connection->makeComment($comment_array));
   }
 
   /**
@@ -288,9 +297,9 @@ public function testMakeComments($expected, $commentArray) {
    */
   public function providerFilterComments() {
     return array(
-      array ('', ''),
-      array ('Exploit * / DROP TABLE node; --', 'Exploit * / DROP TABLE node; --'),
-      array ('Exploit DROP TABLE node; --', 'Exploit */ DROP TABLE node; --'),
+      array('', ''),
+      array('Exploit * / DROP TABLE node; --', 'Exploit * / DROP TABLE node; --'),
+      array('Exploit DROP TABLE node; --', 'Exploit */ DROP TABLE node; --'),
     );
   }
 
@@ -300,17 +309,17 @@ public function providerFilterComments() {
    * @dataProvider providerFilterComments
    */
   public function testFilterComments($expected, $comment) {
-    $mockPDO = $this->getMock('Drupal\Tests\Core\Database\Stub\StubPDO');
-    $connection = new StubConnection($mockPDO, array());
+    $mock_pdo = $this->getMock('Drupal\Tests\Core\Database\Stub\StubPDO');
+    $connection = new StubConnection($mock_pdo, array());
 
     // filterComment() is protected, so we make it accessible with reflection.
     $reflection = new \ReflectionClass('Drupal\Tests\Core\Database\Stub\StubConnection');
-    $filterComment = $reflection->getMethod('filterComment');
-    $filterComment->setAccessible(TRUE);
+    $filter_comment = $reflection->getMethod('filterComment');
+    $filter_comment->setAccessible(TRUE);
 
     $this->assertEquals(
       $expected,
-      $filterComment->invokeArgs($connection, array($comment))
+      $filter_comment->invokeArgs($connection, array($comment))
     );
   }
 
diff --git a/core/tests/Drupal/Tests/Core/Database/Stub/StubPDO.php b/core/tests/Drupal/Tests/Core/Database/Stub/StubPDO.php
index 5653053..c0ea2be 100644
--- a/core/tests/Drupal/Tests/Core/Database/Stub/StubPDO.php
+++ b/core/tests/Drupal/Tests/Core/Database/Stub/StubPDO.php
@@ -11,9 +11,24 @@
  * A stub of \PDO for testing purposes.
  *
  * We override the constructor method so that PHPUnit can mock the \PDO class.
+ * \PDO itself can't be mocked, so we have to create a subclass. This subclass
+ * is being used to unit test Connection, so we don't need a functional database
+ * but we do need a mock \PDO object.
+ *
+ * @see Drupal\Tests\Core\Database\ConnectionTest
+ * @see Drupal\Core\Database\Connection
+ * @see http://stackoverflow.com/questions/3138946/mocking-the-pdo-object-using-phpunit
  */
 class StubPDO extends \PDO {
 
+  /**
+   * Construction method.
+   *
+   * We override this construction method with a no-op in order to mock \PDO
+   * under unit tests.
+   *
+   * @see http://stackoverflow.com/questions/3138946/mocking-the-pdo-object-using-phpunit
+   */
   public function __construct() {
     // No-op.
   }