diff --git a/core/lib/Drupal/Component/Utility/Json.php b/core/lib/Drupal/Component/Utility/Json.php
index 6af136e..54614b5 100644
--- a/core/lib/Drupal/Component/Utility/Json.php
+++ b/core/lib/Drupal/Component/Utility/Json.php
@@ -11,27 +11,40 @@
  * Provides helpers for dealing with json.
  */
 class Json {
+
   /**
    * Converts a PHP variable into its JavaScript equivalent.
    *
    * We use HTML-safe strings, with several characters escaped.
    *
+   * @param mixed $variable
+   *   The variable to encode.
+   *
+   * @return string
+   *   Returns the encoded variable.
+   *
    * @see drupal_json_decode()
    * @ingroup php_wrappers
    */
-  public static function encode($var) {
+  public static function encode($variable) {
     // Encode <, >, ', &, and " using the json_encode() options parameter.
-    return json_encode($var, JSON_HEX_TAG | JSON_HEX_APOS | JSON_HEX_AMP | JSON_HEX_QUOT);
+    return json_encode($variable, JSON_HEX_TAG | JSON_HEX_APOS | JSON_HEX_AMP | JSON_HEX_QUOT);
   }
 
   /**
    * Converts an HTML-safe JSON string into its PHP equivalent.
    *
+   * @param string $string
+   *   The string to decode.
+   *
+   * @return mixed
+   *   Returns the decoded string.
+   *
    * @see drupal_json_encode()
    * @ingroup php_wrappers
    */
-  public static function decode($var) {
-    return json_decode($var, TRUE);
+  public static function decode($string) {
+    return json_decode($string, TRUE);
   }
 
 }
diff --git a/core/tests/Drupal/Tests/Component/Utility/JsonTest.php b/core/tests/Drupal/Tests/Component/Utility/JsonTest.php
index f781d47..e14fc7c 100644
--- a/core/tests/Drupal/Tests/Component/Utility/JsonTest.php
+++ b/core/tests/Drupal/Tests/Component/Utility/JsonTest.php
@@ -2,7 +2,7 @@
 
 /**
  * @file
- * Definition of Drupal\Tests\Component\Utility\JsonTest.
+ * Contains \Drupal\Tests\Component\Utility\JsonTest.
  */
 
 namespace Drupal\Tests\Component\Utility;
@@ -12,8 +12,33 @@
 
 /**
  * Tests the Json::encode() and Json::decode() functions.
+ *
+ * @see \Drupal\Component\Utility\Json
  */
 class JsonTest extends UnitTestCase {
+
+  /**
+   * A test string with the full ASCII table.
+   *
+   * @var string
+   */
+  protected $string;
+
+  /**
+   * An array of unsafe html characters which has to be encoded.
+   *
+   * @var array
+   */
+  protected $htmlUnsafe;
+
+  /**
+   * An array of unsafe html characters which are already escaped.
+   *
+   * @var array
+   */
+  protected $htmlUnsafeEscaped;
+
+
   public static function getInfo() {
     return array(
       'name' => 'JSON',
@@ -23,53 +48,84 @@ public static function getInfo() {
   }
 
   /**
-   * Tests converting PHP variables to JSON strings and back.
+   * {@inheritdoc}
    */
-  function testJSON() {
+  protected function setUp() {
+    parent::setUp();
+
     // Setup a string with the full ASCII table.
     // @todo: Add tests for non-ASCII characters and Unicode.
-    $str = '';
+    $this->string = '';
     for ($i=0; $i < 128; $i++) {
-      $str .= chr($i);
+      $this->string .= chr($i);
     }
+
     // Characters that must be escaped.
     // We check for unescaped " separately.
-    $html_unsafe = array('<', '>', '\'', '&');
+    $this->htmlUnsafe = array('<', '>', '\'', '&');
     // The following are the encoded forms of: < > ' & "
-    $html_unsafe_escaped = array('\u003C', '\u003E', '\u0027', '\u0026', '\u0022');
+    $this->htmlUnsafeEscaped = array('\u003C', '\u003E', '\u0027', '\u0026', '\u0022');
+  }
 
+  /**
+   * Tests encoding for every ASCII character.
+   */
+  public function testEncodingAscii() {
     // Verify there aren't character encoding problems with the source string.
-    $this->assertSame(strlen($str), 128, 'A string with the full ASCII table has the correct length.');
-    foreach ($html_unsafe as $char) {
-      $this->assertTrue(strpos($str, $char) > 0, sprintf('A string with the full ASCII table includes %s.', $char));
+    $this->assertSame(strlen($this->string), 128, 'A string with the full ASCII table has the correct length.');
+    foreach ($this->htmlUnsafe as $char) {
+      $this->assertTrue(strpos($this->string, $char) > 0, sprintf('A string with the full ASCII table includes %s.', $char));
     }
+  }
 
+  /**
+   * Tests encoding length.
+   */
+  public function testEncodingLength() {
     // Verify that JSON encoding produces a string with all of the characters.
-    $json = Json::encode($str);
-    $this->assertTrue(strlen($json) > strlen($str), 'A JSON encoded string is larger than the source string.');
+    $json = Json::encode($this->string);
+    $this->assertTrue(strlen($json) > strlen($this->string), 'A JSON encoded string is larger than the source string.');
+  }
 
+  /**
+   * Tests end and start of the encoded string.
+   */
+  public function testEncodingStartEnd() {
+    $json = Json::encode($this->string);
     // The first and last characters should be ", and no others.
     $this->assertTrue($json[0] == '"', 'A JSON encoded string begins with ".');
     $this->assertTrue($json[strlen($json) - 1] == '"', 'A JSON encoded string ends with ".');
     $this->assertTrue(substr_count($json, '"') == 2, 'A JSON encoded string contains exactly two ".');
+  }
 
+  /**
+   * Tests converting PHP variables to JSON strings and back.
+   */
+  public function testReversibility() {
+    $json = Json::encode($this->string);
     // Verify that encoding/decoding is reversible.
     $json_decoded = Json::decode($json);
-    $this->assertSame($str, $json_decoded, 'Encoding a string to JSON and decoding back results in the original string.');
+    $this->assertSame($this->string, $json_decoded, 'Encoding a string to JSON and decoding back results in the original string.');
+  }
 
+  /**
+   * Test the reversibility of structured data
+   */
+  public function testStructuredReversibility() {
     // Verify reversibility for structured data. Also verify that necessary
     // characters are escaped.
-    $source = array(TRUE, FALSE, 0, 1, '0', '1', $str, array('key1' => $str, 'key2' => array('nested' => TRUE)));
+    $source = array(TRUE, FALSE, 0, 1, '0', '1', $this->string, array('key1' => $this->string, 'key2' => array('nested' => TRUE)));
     $json = Json::encode($source);
-    foreach ($html_unsafe as $char) {
+    foreach ($this->htmlUnsafe as $char) {
       $this->assertTrue(strpos($json, $char) === FALSE, sprintf('A JSON encoded string does not contain %s.', $char));
     }
     // Verify that JSON encoding escapes the HTML unsafe characters
-    foreach ($html_unsafe_escaped as $char) {
+    foreach ($this->htmlUnsafeEscaped as $char) {
       $this->assertTrue(strpos($json, $char) > 0, sprintf('A JSON encoded string contains %s.', $char));
     }
     $json_decoded = Json::decode($json);
-    $this->assertNotSame($source, $json, 'An array encoded in JSON is not identical to the source.');
-    $this->assertSame($source, $json_decoded, 'Encoding structured data to JSON and decoding back results in the original data.');
+    $this->assertNotSame($source, $json, 'An array encoded in JSON is identical to the source.');
+    $this->assertSame($source, $json_decoded, 'Encoding structured data to JSON and decoding back not results in the original data.');
   }
+
 }