function isSerialized(), with tests

README.md

@@ -25,6 +25,7 @@ A PHP library with a variety of string manipulation functions with multibyte sup
     * [isBlank](#isblank)
     * [isHexadecimal](#ishexadecimal)
     * [isLowerCase](#islowercase)
+    * [isSerialized](#isserialized)
     * [isUpperCase](#isuppercase)
     * [last](#last)
     * [length](#length)
@@ -364,6 +365,19 @@ S::create('fòô bàř', 'UTF-8')->isLowerCase();
 S::isLowerCase('fòô bàř', 'UTF-8');  // true
 ```
 
+#### isSerialized
+
+$stringy->isSerialized()
+
+S::isSerialized(string $str [, string $encoding ])
+
+Returns true if the string is serialized, false otherwise.
+
+```php
+S::create('a:1:{s:3:"foo";s:3:"bar";}',, 'UTF-8')->isSerialized();
+S::isSerialized('a:1:{s:3:"foo";s:3:"bar";}', 'UTF-8');  // true
+```
+
 #### isUpperCase
 
 $stringy->isUpperCase()

src/Stringy/StaticStringy.php

@@ -636,6 +636,18 @@ class StaticStringy
         return Stringy::create($str, $encoding)->isLowerCase();
     }
 
+    /**
+     * Returns true if the string is serialized, false otherwise.
+     *
+     * @param   string   $str       String to check
+     * @param   string   $encoding  The character encoding
+     * @return  bool     Whether or not $str is serialized
+     */
+    public static function isSerialized($str, $encoding = null)
+    {
+        return Stringy::create($str, $encoding)->isSerialized();
+    }
+
     /**
      * Returns true if the string contains only upper case chars, false otherwise.
      *

src/Stringy/Stringy.php

@@ -1014,6 +1014,16 @@ class Stringy
         return $this->matchesPattern('^([[:upper:]])*$');
     }
 
+    /**
+     * Returns true if the string is serialized, false otherwise.
+     *
+     * @return  bool  Whether or not $str is serialized
+     */
+    public function isSerialized()
+    {
+        return $this->str === 'b:0;' || @unserialize($this->str) !== false;
+    }
+
     /**
      * Returns the number of occurrences of $substring in the given string.
      * An alias for mb_substr_count()

tests/Stringy/CommonTest.php

@@ -782,6 +782,21 @@ abstract class CommonTest extends PHPUnit_Framework_TestCase
         return $testData;
     }
 
+    public function stringsForIsSerialized()
+    {
+        $testData = array(
+            array(false, ''),
+            array(true, 'a:1:{s:3:"foo";s:3:"bar";}'),
+            array(false, 'a:1:{s:3:"foo";s:3:"bar"}'),
+            array(true, serialize(false)),
+            array(true, 'a:1:{s:3:"foo";s:3:"bar";}', 'UTF-8'),
+            array(false, 'a:1:{s:3:"foo";s:3:"bar"}', 'UTF-8'),
+            array(true, serialize(false), 'UTF-8'),
+        );
+
+        return $testData;
+    }
+
     public function stringsForIsUpperCase()
     {
         $testData = array(

tests/Stringy/StaticStringyTest.php

@@ -472,6 +472,16 @@ class StaticStringyTestCase extends CommonTest
         $this->assertEquals($expected, $result);
     }
 
+    /**
+     * @dataProvider stringsForIsSerialized
+     */
+    public function testIsSerialized($expected, $str, $encoding = null)
+    {
+        $result = S::isSerialized($str, $encoding);
+        $this->assertInternalType('boolean', $result);
+        $this->assertEquals($expected, $result);
+    }
+
     /**
      * @dataProvider stringsForIsUpperCase
      */

tests/Stringy/StringyTest.php

@@ -550,6 +550,18 @@ class StringyTestCase extends CommonTest
         $this->assertEquals($str, $stringy);
     }
 
+    /**
+     * @dataProvider stringsForIsSerialized
+     */
+    public function testIsSerialized($expected, $str, $encoding = null)
+    {
+        $stringy = S::create($str, $encoding);
+        $result = $stringy->isSerialized();
+        $this->assertInternalType('boolean', $result);
+        $this->assertEquals($expected, $result);
+        $this->assertEquals($str, $stringy);
+    }
+
     /**
      * @dataProvider stringsForIsUpperCase
      */