Added Arr::unique and Collection::unique

Author: pdscopes

src/Arr.php

@@ -109,6 +109,19 @@ public static function filter($array, callable $callback)
         return array_filter($array, $callback, ARRAY_FILTER_USE_BOTH);
     }
 
+    /**
+     * Get a subset of unique items from $array.
+     *
+     * @param ArrayAccess|array  $array
+     * @param int                $flag
+     *
+     * @return array
+     */
+    public static function unique($array, $flag = SORT_STRING)
+    {
+        return array_unique($array, $flag);
+    }
+
     /**
      * @param ArrayAccess|array $array
      * @param string|int        $key

src/Collection.php

@@ -173,6 +173,17 @@ public function filter(callable $callback = null)
         return new static(array_filter($this->items));
     }
 
+    /**
+     * Get a subset of unique items from Collection.
+     *
+     * @param int $flag
+     * @return static
+     */
+    public function unique($flag = SORT_REGULAR)
+    {
+        return new static(Arr::unique($this->items, $flag));
+    }
+
     /**
      * Search the collection and return the first corresponding item if successful.
      * If $needle is a callable then return the first item where the callable

tests/Unit/ArrTest.php

@@ -126,6 +126,17 @@ public function testFilter()
         }));
     }
 
+    public function unique()
+    {
+        $completeArray = [3,3, 5,5,5,5, 7,7,7,7,7,7, 9,9,9,9,9,9,9,9];
+        $filteredArray = [3, 5, 7, 9];
+
+        $this->assertEquals($filteredArray, Arr::unique($completeArray));
+
+        $completeDots = new Dots($completeArray);
+        $this->assertEquals($filteredArray, Arr::unique($completeDots));
+    }
+
     public function testExists()
     {
         $array = [

tests/Unit/CollectionTest.php

@@ -164,6 +164,25 @@ public function testFilter()
         $this->assertEquals($partialArray, $filtered->all());
     }
 
+    public function testUnique()
+    {
+        $completeArray = [
+            'one' => 'value a',
+            'two' => 'value b',
+            'three' => 'value a',
+            'four' => 'value b'
+        ];
+        $uniqueArray = [
+            'one' => 'value a',
+            'two' => 'value b',
+        ];
+        $collection = new Collection($completeArray);
+        $filtered   = $collection->unique();
+
+        $this->assertEquals($completeArray, $collection->all());
+        $this->assertEquals($uniqueArray, $filtered->all());
+    }
+
     public function testFind()
     {
         $items = [