Created rule "Exists"

This rule checks if the given data is a path of a regular file or
directory.

README.md

@@ -287,6 +287,7 @@ Reference
   * v::directory()
   * v::domain()
   * v::email()
+  * v::exists()
   * v::file()
   * v::ip()
   * v::json()
@@ -719,11 +720,17 @@ See also:
 Validates directories.
 
     v::directory()->validate(__DIR__); //true
+    v::directory()->validate(__FILE__); //false
 
 This validator will consider SplFileInfo instances, so you can do something like:
 
     v::directory()->validate(new \SplFileInfo($directory));
 
+See also
+
+  * v::exists()
+  * v::file()
+
 #### v::each(v $validatorForValue)
 #### v::each(null, v $validatorForKey)
 #### v::each(v $validatorForValue, v $validatorForKey)
@@ -753,6 +760,22 @@ Validates an email address.
 
     v::email()->validate('alexandre@gaigalas.net'); //true
 
+#### v::exists()
+
+Validates files or directories.
+
+    v::exists()->validate(__FILE__); //true
+    v::exists()->validate(__DIR__); //true
+
+This validator will consider SplFileInfo instances, so you can do something like:
+
+    v::exists()->validate(new \SplFileInfo($file));
+
+See also
+
+  * v::directory()
+  * v::file()
+
 #### v::endsWith($value)
 #### v::endsWith($value, boolean $identical=false)
 
@@ -814,11 +837,17 @@ See also
 Validates files.
 
     v::file()->validate(__FILE__); //true
+    v::file()->validate(__DIR__); //false
 
 This validator will consider SplFileInfo instances, so you can do something like:
 
     v::file()->validate(new \SplFileInfo($file));
 
+See also
+
+  * v::directory()
+  * v::exists()
+
 #### v::float()
 
 Validates a floating point number.

library/Respect/Validation/Exceptions/ExistsException.php

@@ -0,0 +1,17 @@
+<?php
+
+namespace Respect\Validation\Exceptions;
+
+class ExistsException extends ValidationException
+{
+
+    public static $defaultTemplates = array(
+        self::MODE_DEFAULT => array(
+            self::STANDARD => '{{name}} must exists',
+        ),
+        self::MODE_NEGATIVE => array(
+            self::STANDARD => '{{name}} must not exists',
+        )
+    );
+
+}

library/Respect/Validation/Rules/Exists.php

@@ -0,0 +1,18 @@
+<?php
+
+namespace Respect\Validation\Rules;
+
+class Exists extends AbstractRule
+{
+
+    public function validate($input)
+    {
+        if ($input instanceof \SplFileInfo) {
+            $input = $input->getPathname();
+        }
+
+        return (is_string($input) && file_exists($input));
+    }
+
+}
+

library/Respect/Validation/Validator.php

@@ -38,6 +38,7 @@ use Respect\Validation\Rules\AllOf;
  * @method \Respect\Validation\Validator equals(mixed $compareTo, bool $compareIdentical=false)
  * @method \Respect\Validation\Validator even()
  * @method \Respect\Validation\Validator file()
+ * @method \Respect\Validation\Validator exists()
  * @method \Respect\Validation\Validator float()
  * @method \Respect\Validation\Validator graph(string $additionalChars = null)
  * @method \Respect\Validation\Validator in(array $haystack, bool $compareIdentical = false)

tests/library/Respect/Validation/Rules/ExistsTest.php

@@ -0,0 +1,58 @@
+<?php
+
+namespace Respect\Validation\Rules;
+
+$GLOBALS['file_exists'] = null;
+
+function file_exists($file)
+{
+    $return = \file_exists($file); // Running the real function
+    if (null !== $GLOBALS['file_exists']) {
+        $return                 = $GLOBALS['file_exists'];
+        $GLOBALS['file_exists'] = null;
+    }
+
+    return $return;
+}
+
+class ExistsTest extends \PHPUnit_Framework_TestCase
+{
+
+    /**
+     * @covers Respect\Validation\Rules\Exists::validate
+     */
+    public function testExistentFileShouldReturnTrue()
+    {
+        $GLOBALS['file_exists'] = true;
+
+        $rule = new Exists();
+        $input = '/path/of/an/existent/file';
+        $this->assertTrue($rule->validate($input));
+    }
+
+    /**
+     * @covers Respect\Validation\Rules\Exists::validate
+     */
+    public function testNonExistentFileShouldReturnFalse()
+    {
+        $GLOBALS['file_exists'] = false;
+
+        $rule = new Exists();
+        $input = '/path/of/a/non-existent/file';
+        $this->assertFalse($rule->validate($input));
+    }
+
+    /**
+     * @covers Respect\Validation\Rules\Exists::validate
+     */
+    public function testShouldValidateObjects()
+    {
+        $GLOBALS['file_exists'] = true;
+
+        $rule = new Exists();
+        $object = new \SplFileInfo('/path/of/an/existent/file');
+
+        $this->assertTrue($rule->validate($object));
+    }
+
+}