Fix #556 Adding sparce & unique indices (#835)

* Adding sparce & unique indices

Provides a handy workaround for issue 556.

* Code styling fix

This addresses the issues highlighted in the StyleCI analysis.

src/Jenssegers/Mongodb/Schema/Blueprint.php

@@ -222,6 +222,25 @@ class Blueprint extends \Illuminate\Database\Schema\Blueprint
         return $this;
     }
 
+    /**
+     * Specify a sparse and unique index for the collection.
+     *
+     * @param  string|array  $columns
+     * @param  array         $options
+     * @return Blueprint
+     */
+    public function sparse_and_unique($columns = null, $options = [])
+    {
+        $columns = $this->fluent($columns);
+
+        $options['sparse'] = true;
+        $options['unique'] = true;
+
+        $this->index($columns, $options);
+
+        return $this;
+    }
+
     /**
      * Allow fluent columns.
      *

tests/SchemaTest.php

@@ -175,6 +175,17 @@ class SchemaTest extends TestCase
         });
     }
 
+    public function testSparseUnique()
+    {
+        Schema::collection('newcollection', function ($collection) {
+          $collection->sparse_and_unique('sparseuniquekey');
+        });
+
+        $index = $this->getIndex('newcollection', 'sparseuniquekey');
+        $this->assertEquals(1, $index['sparse']);
+        $this->assertEquals(1, $index['unique']);
+    }
+
     protected function getIndex($collection, $name)
     {
         $collection = DB::getCollection($collection);