Allow null value for card_number (#37)

* Remove type hint from card_number parameters

* Add null value to bad card number test

* fix test data

* remove trailing whitespace

Author: avrahamappel

src/Factory.php

@@ -40,23 +40,23 @@ class Factory
     ];
 
     /**
-     * @param string $card_number
+     * @param string|mixed $card_number
      *
      * @return \LVR\CreditCard\Cards\Card
      * @throws \LVR\CreditCard\Exceptions\CreditCardException
      */
-    public static function makeFromNumber(string $card_number)
+    public static function makeFromNumber($card_number)
     {
         return self::determineCardByNumber($card_number);
     }
 
     /**
-     * @param string $card_number
+     * @param string|mixed $card_number
      *
      * @return mixed
      * @throws \LVR\CreditCard\Exceptions\CreditCardException
      */
-    protected static function determineCardByNumber(string $card_number)
+    protected static function determineCardByNumber($card_number)
     {
         foreach (self::$available_cards as $card) {
             if (preg_match($card::$pattern, $card_number)) {

tests/Unit/CardTest.php

@@ -10,12 +10,17 @@
 
 class CardTest extends TestCase
 {
-    /** @test **/
-    public function it_expects_card_number()
+    /** @test @dataProvider badStrings **/
+    public function it_expects_card_number($input)
     {
         $this->expectException(CreditCardException::class);
 
-        Factory::makeFromNumber('');
+        Factory::makeFromNumber($input);
+    }
+
+    public function badStrings()
+    {
+        return ['empty string' => [''], 'null' => [null]];
     }
 
     /** @test **/