Add filter alias for Strings::concat

Author: chadicus

README.md

@@ -224,6 +224,13 @@ The following checks that `$value` is a non-empty string.
 \TraderInteractive\Filter\Strings::filter($value);
 ```
 
+#### Strings::concat
+Aliased in the filterer as `concat`, this filter concatenates the given $value, $prefix and $suffix and returns the resulting string.
+```php
+$value = \TraderInteractive\Filter\Strings::concat('middle', 'begining_', '_end');
+assert($value === 'begining_middle_end');
+```
+
 #### Strings::explode
 Aliased in the filterer as `explode`, this filter is essentially a wrapper around the built-in [`explode`](http://www.php.net/explode) method
 with the value first in order to work with the `Filterer`.  It also defaults to using `,` as a delimiter.  For example:

composer.json

@@ -35,7 +35,7 @@
         "traderinteractive/filter-dates": "^3.0",
         "traderinteractive/filter-floats": "^3.0",
         "traderinteractive/filter-ints": "^3.0",
-        "traderinteractive/filter-strings": "^3.1"
+        "traderinteractive/filter-strings": "^3.2.0"
     },
     "require-dev": {
         "php-coveralls/php-coveralls": "^1.0",

src/Filterer.php

@@ -19,6 +19,7 @@ final class Filterer
         'arrayize' => '\\TraderInteractive\\Filter\\Arrays::arrayize',
         'bool' => '\\TraderInteractive\\Filter\\Booleans::filter',
         'bool-convert' => '\\TraderInteractive\\Filter\\Booleans::convert',
+        'concat' => '\\TraderInteractive\\Filter\\Strings::concat',
         'date' => '\\TraderInteractive\\Filter\\DateTime::filter',
         'date-format' => '\\TraderInteractive\\Filter\\DateTime::format',
         'email' => '\\TraderInteractive\\Filter\\Email::filter',

tests/FiltererTest.php

@@ -659,4 +659,16 @@ public function arrayizeAliasIsCalledProperly()
             Filterer::filter(['field' => [['arrayize']]], ['field' => 'a string value'])
         );
     }
+
+    /**
+     * @tests
+     * @covers ::filter
+     */
+    public function concatAliasIsCalledProperly()
+    {
+        $this->assertSame(
+            [true, ['field' => '%value%'], null, []],
+            Filterer::filter(['field' => [['concat', '%', '%']]], ['field' => 'value'])
+        );
+    }
 }