use Luhn to calculate ar_SA id numbers.

readme.md

@@ -745,6 +745,7 @@ Fugiat non in itaque sunt nobis totam. Sed nesciunt est deleniti cumque alias. R
 echo $faker->idNumber;      // ID number
 echo $faker->nationalIdNumber // Citizen ID number
 echo $faker->foreignerIdNumber // Foreigner ID number
+echo $faker->companyIdNumber // Company ID number
 ```
 
 ### `Faker\Provider\at_AT\Payment`

src/Faker/Calculator/Luhn.php

@@ -2,8 +2,11 @@
 
 namespace Faker\Calculator;
 
+use Faker\Provider\Base as BaseProvider;
+use InvalidArgumentException;
+
 /**
- * Utility class for generating Luhn checksum and validating a number
+ * Utility class for generating and validating Luhn numbers.
  *
  * Luhn algorithm is used to validate credit card numbers, IMEI numbers, and
  * National Provider Identifier numbers.
@@ -55,4 +58,41 @@ public static function isValid($number)
     {
         return self::checksum($number) === 0;
     }
+
+    /**
+     * Generate a Luhn compliant number.
+     *
+     * @param string $prefix
+     * @param int $length
+     * @return string
+     */
+    public static function generateLuhnNumber($prefix, $length)
+    {
+        $length = intval($length);
+        $prefix = trim($prefix);
+
+        if (!preg_match('/^\d*$/', $prefix)) {
+            throw new InvalidArgumentException('prefix should be all digits.');
+        }
+
+        if ($length <= 0) {
+            throw new InvalidArgumentException('length should be greater than zero.');
+        }
+
+        if (strlen($prefix) > $length) {
+            throw new InvalidArgumentException('prefix should be longer than the length.');
+        }
+
+        if (strlen($prefix) == $length) {
+            if (static::isValid($prefix)) {
+                return $prefix;
+            } else {
+                throw new InvalidArgumentException('prefix length equals length but prefix is not a Luhn number.');
+            }
+        }
+
+        $pattern = $prefix . str_repeat('#', $length - strlen($prefix) - 1);
+        $partialValue = BaseProvider::numerify($pattern);
+        return $partialValue . Luhn::computeCheckDigit($partialValue);
+    }
 }

src/Faker/Provider/ar_SA/Company.php

@@ -2,6 +2,8 @@
 
 namespace Faker\Provider\ar_SA;
 
+use Faker\Calculator\Luhn;
+
 class Company extends \Faker\Provider\Company
 {
     protected static $formats = array(
@@ -60,4 +62,12 @@ public function bs()
 
         return join($result, ' ');
     }
+
+    /**
+     * example 7001010101
+     **/
+    public static function companyIdNumber()
+    {
+        return Luhn::generateLuhnNumber(700, 10);
+    }
 }

src/Faker/Provider/ar_SA/Person.php

@@ -2,6 +2,8 @@
 
 namespace Faker\Provider\ar_SA;
 
+use Faker\Calculator\Luhn;
+
 class Person extends \Faker\Provider\Person
 {
     protected static $maleNameFormats = array(
@@ -90,59 +92,23 @@ public static function prefix()
      */
     public static function idNumber()
     {
-        $firstDigit = static::numberBetween(1, 2);
-
-        do {
-            $number = $firstDigit.static::numerify('#########');
-        } while (!static::checkSum($number));
-
-        return $number;
+        $firstDigit = static::randomElement(array(1, 2));
+        return Luhn::generateLuhnNumber($firstDigit, 10);
     }
 
     /**
-     * @example
+     * @example 1010101010
      */
     public static function nationalIdNumber()
     {
-        do {
-            $number = '1'.static::numerify('#########');
-        } while (!static::checkSum($number));
-
-        return $number;
+        return Luhn::generateLuhnNumber(1, 10);
     }
 
     /**
-     * @example
+     * @example 2010101010
      */
     public static function foreignerIdNumber()
     {
-        do {
-            $number = '2'.static::numerify('#########');
-        } while (!static::checkSum($number));
-
-        return $number;
-    }
-
-    /**
-     * Check sum the number.
-     * @param $number
-     *
-     * @return bool
-     */
-    protected static function checkSum($number)
-    {
-        $sum  = 0;
-        $nums = str_split($number);
-
-        for ($i = 0; $i < 10; $i++) {
-            if ($i % 2 == 0) {
-                $s = $nums[$i] * 2;
-                $sum += $s % 10 + floor($s / 10);
-            } else {
-                $sum += $nums[$i];
-            }
-        }
-
-        return ($sum % 10 == 0);
+        return Luhn::generateLuhnNumber(2, 10);
     }
 }

test/Faker/Calculator/LuhnTest.php

@@ -59,4 +59,60 @@ public function testIsValid($number, $isValid)
     {
         $this->assertEquals($isValid, Luhn::isValid($number));
     }
+
+    public function generateLuhnNumberProvider()
+    {
+        return array(
+            array(' ', 5),
+            array(null, 7),
+            array(443, 10),
+            array(5, 15),
+            array(203, 25),
+        );
+    }
+
+    /**
+     * @dataProvider generateLuhnNumberProvider
+     */
+    public function testGenerateLuhnNumber($prefix, $length)
+    {
+        $this->assertEquals($length, strlen(Luhn::generateLuhnNumber($prefix, $length)));
+        $this->assertTrue(Luhn::isValid(Luhn::generateLuhnNumber($prefix, $length)));
+    }
+
+    /**
+     * @expectedException        InvalidArgumentException
+     * @expectedExceptionMessage prefix should be all digits.
+     */
+    public function testGenerateLuhnNumberWithInvalidPrefix()
+    {
+        Luhn::generateLuhnNumber('abc', 10);
+    }
+
+    /**
+     * @expectedException        InvalidArgumentException
+     * @expectedExceptionMessage length should be greater than zero.
+     */
+    public function testGenerateLuhnNumberWithNegativeLength()
+    {
+        Luhn::generateLuhnNumber(1, -5);
+    }
+
+    /**
+     * @expectedException        InvalidArgumentException
+     * @expectedExceptionMessage prefix should be longer than the length.
+     */
+    public function testGenerateLuhnNumberWithPrefixGreaterThanLength()
+    {
+        Luhn::generateLuhnNumber(123456, 5);
+    }
+
+    /**
+     * @expectedException        InvalidArgumentException
+     * @expectedExceptionMessage prefix length equals length but prefix is not a Luhn number.
+     */
+    public function testGenerateLuhnNumberWithPrefixEqualLengthButInvalid()
+    {
+        Luhn::generateLuhnNumber(123457, 6);
+    }
 }