Merge pull request #6 from xi-project/remove-state-from-luhn

Removed state from Luhn

Author: panunu

.gitignore

@@ -1,4 +1,5 @@
 composer.phar
 composer.lock
 tests/phpunit.xml
-vendor
+vendor
+.idea

README.md

@@ -1,13 +1,27 @@
-# Luhn
+# Xi Algorithm
+
+## Luhn
+
+Usage:
 
 ```
-$luhn = new Luhn(1234);
-$luhn->generate();
+use Xi\Algorithm\Luhn;
+
+$luhn = new Luhn();
+$luhn->generate(123); // 1230
 ```
 
-# Tests
+## Running the tests
+
+No dependencies to other libraries exist, but in order to generate an autoloader
+first run
 
-No dependencies to other libraries exist, but in order to generate an autoloader and run tests, first run
 ```
 composer.phar install --dev
 ```
+
+and then run the tests with
+
+```
+phpunit -c tests
+```

library/Xi/Algorithm/Luhn.php

@@ -4,32 +4,20 @@
 
 class Luhn
 {
-    /**
-     * @var integer
-     */
-    private $number;
-
-    /**
-     * @param integer $number
-     */
-    public function __construct($number)
-    {
-        $this->number = $number;
-    }
-
     /**
      * Returns the given number with luhn algorithm applied.
      *
      * For example 456 becomes 4564.
      *
+     * @param  integer $number
      * @return integer
      */
-    public function generate()
+    public function generate($number)
     {
         $stack = 0;
-        $number = str_split(strrev($this->number), 1);
+        $digits = str_split(strrev($number), 1);
 
-        foreach ($number as $key => $value) {
+        foreach ($digits as $key => $value) {
             if ($key % 2 === 0) {
                 $value = array_sum(str_split($value * 2, 1));
             }
@@ -43,6 +31,6 @@ public function generate()
             $stack -= 10;
         }
 
-        return (int) (implode('', array_reverse($number)) . abs($stack));
+        return (int) (implode('', array_reverse($digits)) . abs($stack));
     }
 }

tests/Xi/Tests/Algorithm/LuhnTest.php

@@ -18,8 +18,8 @@ class LuhnTest extends \PHPUnit_Framework_TestCase
      */
     public function generatesLuhnChecksum($number, $expected)
     {
-        $luhn = new Luhn($number);
-        $luhnedNumber = $luhn->generate();
+        $luhn = new Luhn();
+        $luhnedNumber = $luhn->generate($number);
 
         $this->assertInternalType('integer', $luhnedNumber);
         $this->assertEquals($expected, $luhnedNumber);