Add surround and insert

README.md

@@ -315,16 +315,28 @@ Returns true if $haystack contains $needle, false otherwise.
 S::contains('Ο συγγραφέας είπε', 'συγγραφέας', 'UTF-8') // true
 ```
 
+##### surround
+
+S::surround(string $str, string $substring)
+
+Surrounds a string with the given substring.
+
+```php
+S::surround(' ͜ ', 'ʘ'); // 'ʘ ͜ ʘ'
+```
+
+##### insert
+
+S::insert(string $str, int $index, string $substring [, string $encoding ])
+
+Inserts $substring into $str at the $index provided.
+
+```php
+S::insert('fòô bà', 'ř', 6, 'UTF-8'); // 'fòô bàř'
+```
+
 ## TODO
 
-**between**
-
-**surround**
-
-**replace** => substr_replace
-
-**insert**
-
 **truncate**
 
 **prune**

src/Stringy/Stringy.php

@@ -474,7 +474,7 @@ class Stringy {
      * @param   string  $encoding  The character encoding
      * @return  bool    Whether or not $haystack contains $needle
      */
-    public static function contains($haystack, $needle, $encoding) {
+    public static function contains($haystack, $needle, $encoding = null) {
         $encoding = $encoding ?: mb_internal_encoding();
 
         if (mb_strpos($haystack, $needle, 0, $encoding) !== false)
@@ -483,6 +483,38 @@ class Stringy {
         return false;
     }
 
+    /**
+     * Surrounds a string with the given substring.
+     *
+     * @param   string  $str        The string to surround
+     * @param   string  $substring  The substring to add to both sides
+     * @return  string  The string with the substring prepended and appended
+     */
+    public static function surround($str, $substring) {
+        return implode('', array($substring, $str, $substring));
+    }
+
+    /**
+     * Inserts $substring into $str at the $index provided.
+     *
+     * @param   string  $str        String to insert into
+     * @param   string  $substring  String to be inserted
+     * @param   int     $index      The index at which to insert the substring
+     * @param   string  $encoding   The character encoding
+     * @return  string  The resulting string after the insertion
+     */
+    public static function insert($str, $substring, $index, $encoding = null) {
+        $encoding = $encoding ?: mb_internal_encoding();
+
+        if ($index > mb_strlen($str))
+            return $str;
+
+        $start = mb_substr($str, 0, $index, $encoding);
+        $end = mb_substr($str, $index, mb_strlen($str), $encoding);
+
+        return $start . $substring . $end;
+    }
+
 }
 
 ?>

tests/Stringy/StringyTest.php

@@ -532,6 +532,49 @@ class StringyTestCase extends PHPUnit_Framework_TestCase {
         return $testData;
     }
 
+    /**
+     * @dataProvider stringsForSurround
+     */
+    public function testSurround($expected, $string, $substring) {
+        $result = S::surround($string, $substring);
+        $this->assertEquals($expected, $result);
+    }
+
+    public function stringsForSurround() {
+        $testData = array(
+            array('__foobar__', 'foobar', '__'),
+            array('test', 'test', ''),
+            array('**', '', '*'),
+            array('¬fòô bàř¬', 'fòô bàř', '¬'),
+            array('ßå∆˚ test ßå∆˚', ' test ', 'ßå∆˚')
+        );
+
+        return $testData;
+    }
+
+    /**
+     * @dataProvider stringsForInsert
+     */
+    public function testInsert($expected, $string, $substring, $index,
+                               $encoding = null) {
+        $result = S::insert($string, $substring, $index, $encoding);
+        $this->assertEquals($expected, $result);
+    }
+
+    public function stringsForInsert() {
+        $testData = array(
+            array('foo bar', 'oo bar', 'f', 0),
+            array('foo bar', 'f bar', 'oo', 1),
+            array('f bar', 'f bar', 'oo', 20),
+            array('foo bar', 'foo ba', 'r', 6),
+            array('fòô bàř', 'òô bàř', 'f', 0, 'UTF-8'),
+            array('fòô bàř', 'f bàř', 'òô', 1, 'UTF-8'),
+            array('fòô bàř', 'fòô bà', 'ř', 6, 'UTF-8')
+        );
+
+        return $testData;
+    }
+
 }
 
 ?>