Add 'extension' rule and tests

Usage: ‘extension:pdf,txt’ or ‘extension:.pdf,.txt’

Author: thomasfw

src/Rules/Extension.php

@@ -0,0 +1,50 @@
+<?php
+
+namespace Rakit\Validation\Rules;
+
+use Rakit\Validation\Helper;
+use Rakit\Validation\Rule;
+
+class Extension extends Rule
+{
+    
+    /** @var string */
+    protected $message = "The :attribute must be a :allowed_extensions file";
+
+     /**
+     * Given $params and assign the $this->params
+     *
+     * @param array $params
+     * @return self
+     */
+    public function fillParameters(array $params): Rule
+    {
+        if (count($params) == 1 && is_array($params[0])) {
+            $params = $params[0];
+        }
+        $this->params['allowed_extensions'] = $params;
+        return $this;
+    }
+    
+    /**
+     * Check the $value is valid
+     *
+     * @param mixed $value
+     * @return bool
+     */
+    public function check($value): bool
+    {
+        $this->requireParameters(['allowed_extensions']);
+        $allowedExtensions = $this->parameter('allowed_extensions');
+        foreach($allowedExtensions as $key => $ext){
+            $allowedExtensions[$key] = ltrim($ext,'.');
+        }
+
+        $or = $this->validation ? $this->validation->getTranslation('or') : 'or';
+        $allowedExtensionsText = Helper::join(Helper::wraps($allowedExtensions, ".", ""), ', ', ", {$or} ");
+        $this->setParameterText('allowed_extensions', $allowedExtensionsText);
+
+        $ext = strtolower(pathinfo($value, PATHINFO_EXTENSION));
+        return ($ext && in_array($ext, $allowedExtensions)) ? true : false;
+    }
+}

src/Validator.php

@@ -140,6 +140,7 @@ protected function registerBaseValidators()
             'ip'                        => new Rules\Ip,
             'ipv4'                      => new Rules\Ipv4,
             'ipv6'                      => new Rules\Ipv6,
+            'extension'                 => new Rules\Extension,
             'array'                     => new Rules\TypeArray,
             'same'                      => new Rules\Same,
             'regex'                     => new Rules\Regex,

tests/Rules/ExtensionTest.php

@@ -0,0 +1,33 @@
+<?php
+
+namespace Rakit\Validation\Tests;
+
+use Rakit\Validation\Rules\Extension;
+use PHPUnit\Framework\TestCase;
+
+class ExtensionTest extends TestCase
+{
+
+    public function setUp()
+    {
+        $this->rule = new Extension;
+    }
+
+    public function testValids()
+    {
+        $this->assertTrue($this->rule->fillParameters(['pdf','png','txt'])->check('somefile.txt'));
+        $this->assertTrue($this->rule->fillParameters(['.pdf','.png','.txt'])->check('somefile.txt'));
+        $this->assertTrue($this->rule->fillParameters(['pdf','png','txt'])->check('path/to/somefile.txt'));
+        $this->assertTrue($this->rule->fillParameters(['pdf','png','txt'])->check('./absolute/path/to/somefile.txt'));
+        $this->assertTrue($this->rule->fillParameters(['pdf','png','txt'])->check('https://site.test/somefile.txt'));
+    }
+
+    public function testInvalids()
+    {
+        $this->assertFalse($this->rule->fillParameters(['pdf','png','txt'])->check(''));
+        $this->assertFalse($this->rule->fillParameters(['pdf','png','txt'])->check('.dotfile'));
+        $this->assertFalse($this->rule->fillParameters(['pdf','png','txt'])->check('notafile'));
+        $this->assertFalse($this->rule->fillParameters(['pdf','png','txt'])->check('somefile.php'));
+        $this->assertFalse($this->rule->fillParameters(['.pdf','.png','.txt'])->check('somefile.php'));
+    }
+}