Merge pull request #266 from terite/randomElements

add Faker\Provider\Base::randomElements

readme.md

@@ -177,6 +177,7 @@ Each of the generator properties (like `name`, `address`, and `lorem`) are calle
     randomNumber($from, $to) // 39049
     randomFloat($nbMaxDecimals = NULL, $min = 0, $max = NULL) // 48.8932
     randomLetter            // 'b'
+    randomElements($array = array ('a','b','c'), $count = 1) // array('c')
     randomElement($array = array ('a','b','c')) // 'b'
     numerify($string = '###') // '609'
     lexify($string = '????') // 'wgts'

src/Faker/Provider/Base.php

@@ -123,6 +123,42 @@ class Base
         return chr(mt_rand(97, 122));
     }
 
+    /**
+     * Returns random elements from a provided array
+     *
+     * @param  array   $array Array to take elements from. Defaults to a-f
+     * @param  integer $count Number of elements to take.
+     * @throws \LengthException When requesting more elements than provided
+     *
+     * @return array   New array with $count elements from $array
+     */
+    public static function randomElements(array $array = array('a', 'b', 'c'), $count = 1)
+    {
+        $allKeys = array_keys($array);
+        $numKeys = count($allKeys);
+
+        if ($numKeys < $count) {
+            throw new \LengthException(sprintf('Cannot get %d elements, only %d in array', $count, $numKeys));
+        }
+
+        $highKey = $numKeys - 1;
+        $keys = $elements = array();
+        $numElements = 0;
+
+        while ($numElements < $count) {
+            $num = mt_rand(0, $highKey);
+            if (isset($keys[$num])) {
+                continue;
+            }
+
+            $keys[$num] = true;
+            $elements[] = $array[$allKeys[$num]];
+            $numElements++;
+        }
+
+        return $elements;
+    }
+
     /**
      * Returns a random element from a passed array
      *
@@ -131,7 +167,11 @@ class Base
      */
     public static function randomElement($array = array('a', 'b', 'c'))
     {
-        return $array ? $array[self::randomKey($array)] : null;
+        if (!$array) {
+            return null;
+        }
+        $elements = static::randomElements($array, 1);
+        return $elements[0];
     }
 
     /**

test/Faker/Provider/BaseTest.php

@@ -84,6 +84,11 @@ class BaseTest extends \PHPUnit_Framework_TestCase
         $this->assertTrue(strpos($lowercaseLetters, BaseProvider::randomLetter()) !== false);
     }
 
+    public function testRandomElementReturnsNullWhenArrayEmpty()
+    {
+        $this->assertNull(BaseProvider::randomElement(array()));
+    }
+
     public function testRandomElementReturnsElementFromArray()
     {
         $elements = array('23', 'e', 32, '#');
@@ -229,4 +234,27 @@ class BaseTest extends \PHPUnit_Framework_TestCase
         sort($values);
         $this->assertEquals(array(0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9), $values);
     }
+
+    /**
+     * @expectedException LengthException
+     * @expectedExceptionMessage Cannot get 2 elements, only 1 in array
+     */
+    public function testRandomElementsThrowsWhenRequestingTooManyKeys()
+    {
+        BaseProvider::randomElements(array('foo'), 2);
+    }
+
+    public function testRandomElements()
+    {
+        $this->assertCount(1, BaseProvider::randomElements(), 'Should work without any input');
+
+        $empty = BaseProvider::randomElements(array(), 0);
+        $this->assertInternalType('array', $empty);
+        $this->assertCount(0, $empty);
+
+        $shuffled = BaseProvider::randomElements(array('foo', 'bar', 'baz'), 3);
+        $this->assertContains('foo', $shuffled);
+        $this->assertContains('bar', $shuffled);
+        $this->assertContains('baz', $shuffled);
+    }
 }