From 9903c82496af84601d43e3630b400f17b66521d8 Mon Sep 17 00:00:00 2001
From: Meritoo <github@meritoo.pl>
Date: Mon, 9 Sep 2019 09:41:07 +0200
Subject: [PATCH] Add Miscellaneous::calculateGreatestCommonDivisor() method

---
 src/Utilities/Miscellaneous.php       |  5 +++
 tests/Utilities/MiscellaneousTest.php | 57 +++++++++++++++++++++++++++
 2 files changed, 62 insertions(+)

diff --git a/src/Utilities/Miscellaneous.php b/src/Utilities/Miscellaneous.php
index 4ba0e37..c33290d 100644
--- a/src/Utilities/Miscellaneous.php
+++ b/src/Utilities/Miscellaneous.php
@@ -1319,4 +1319,9 @@ class Miscellaneous
 
         return substr($string, 1);
     }
+
+    public static function calculateGreatestCommonDivisor(int $first, int $second): int
+    {
+        return (0 === $second) ? $first : static::calculateGreatestCommonDivisor($second, $first % $second);
+    }
 }
diff --git a/tests/Utilities/MiscellaneousTest.php b/tests/Utilities/MiscellaneousTest.php
index 93af639..25a714f 100644
--- a/tests/Utilities/MiscellaneousTest.php
+++ b/tests/Utilities/MiscellaneousTest.php
@@ -735,6 +735,18 @@ class MiscellaneousTest extends BaseTestCase
         self::assertEquals($expected, Miscellaneous::removeMarginalCharacter($string, $last), $description);
     }
 
+    /**
+     * @param int $first
+     * @param int $second
+     * @param int $expected
+     *
+     * @dataProvider provideGreatestCommonDivisor
+     */
+    public function testCalculateGreatestCommonDivisor(int $first, int $second, int $expected): void
+    {
+        static::assertSame($expected, Miscellaneous::calculateGreatestCommonDivisor($first, $second));
+    }
+
     /**
      * Provides string to convert characters to latin characters and not lower cased and not human-readable
      *
@@ -1506,6 +1518,51 @@ class MiscellaneousTest extends BaseTestCase
         ];
     }
 
+    public function provideGreatestCommonDivisor(): ?Generator
+    {
+        yield[
+            0,
+            0,
+            0,
+        ];
+
+        yield[
+            1,
+            1,
+            1,
+        ];
+
+        yield[
+            5,
+            3,
+            1,
+        ];
+
+        yield[
+            6,
+            3,
+            3,
+        ];
+
+        yield[
+            12,
+            9,
+            3,
+        ];
+
+        yield[
+            20,
+            12,
+            4,
+        ];
+
+        yield[
+            120,
+            80,
+            40,
+        ];
+    }
+
     /**
      * {@inheritdoc}
      */