Adds exceptions to fix picqer#7

Author: casperbakker

src/BarcodeGenerator.php

@@ -29,6 +29,8 @@
 
 namespace Picqer\Barcode;
 
+use Picqer\Barcode\Exceptions\InvalidCharacterException;
+
 abstract class BarcodeGenerator
 {
     const TYPE_CODE_39 = 'C39';
@@ -1638,6 +1640,9 @@ protected function barcode_eanupc($code, $len = 13)
             }
             $seq .= '01010'; // center guard bar
             for ($i = $half_len; $i < $len; ++$i) {
+                if ( ! isset($codes['C'][$code{$i}])) {
+                    throw new InvalidCharacterException('Char ' . $code{$i} . ' not allowed');
+                }
                 $seq .= $codes['C'][$code{$i}];
             }
             $seq .= '101'; // right guard bar

src/Exceptions/BarcodeException.php

@@ -0,0 +1,5 @@
+<?php
+
+namespace Picqer\Barcode\Exceptions;
+
+class BarcodeException extends \Exception {}

src/Exceptions/InvalidCharacterException.php

@@ -0,0 +1,5 @@
+<?php
+
+namespace Picqer\Barcode\Exceptions;
+
+class InvalidCharacterException extends BarcodeException {}

tests/BarcodeTest.php

@@ -43,4 +43,14 @@ public function jpg_barcode_generator_can_generate_code_128_barcode()
         $generator = new Picqer\Barcode\BarcodeGeneratorJPG();
         $generator->getBarcode('081231723897', $generator::TYPE_CODE_128);
     }
+
+    /**
+     * @test
+     * @expectedException \Picqer\Barcode\Exceptions\InvalidCharacterException
+     */
+    public function ean13_generator_throws_exception_if_invalid_chars_are_used()
+    {
+        $generator = new Picqer\Barcode\BarcodeGeneratorSVG();
+        $generator->getBarcode('A123', $generator::TYPE_EAN_13);
+    }
 }