Add cursor support

src/Jenssegers/Mongodb/Query/Builder.php

@@ -8,14 +8,20 @@
 use Illuminate\Database\Query\Expression;
 use Illuminate\Support\Arr;
 use Illuminate\Support\Collection;
+use Illuminate\Support\LazyCollection;
 use Illuminate\Support\Str;
 use Jenssegers\Mongodb\Connection;
 use MongoCollection;
 use MongoDB\BSON\Binary;
 use MongoDB\BSON\ObjectID;
 use MongoDB\BSON\Regex;
 use MongoDB\BSON\UTCDateTime;
+use RuntimeException;
 
+/**
+ * Class Builder
+ * @package Jenssegers\Mongodb\Query
+ */
 class Builder extends BaseBuilder
 {
     /**
@@ -209,12 +215,25 @@ public function get($columns = [])
         return $this->getFresh($columns);
     }
 
+    /**
+     * @inheritdoc
+     */
+    public function cursor($columns = [])
+    {
+        $result =  $this->getFresh($columns, true);
+        if ($result instanceof LazyCollection) {
+            return $result;
+        }
+        throw new RuntimeException("Query not compatible with cursor");
+    }
+
     /**
      * Execute the query as a fresh "select" statement.
      * @param array $columns
-     * @return array|static[]|Collection
+     * @param bool $returnLazy
+     * @return array|static[]|Collection|LazyCollection
      */
-    public function getFresh($columns = [])
+    public function getFresh($columns = [], $returnLazy = false)
     {
         // If no columns have been specified for the select statement, we will set them
         // here to either the passed columns, or the standard default of retrieving
@@ -402,6 +421,14 @@ public function getFresh($columns = [])
             // Execute query and get MongoCursor
             $cursor = $this->collection->find($wheres, $options);
 
+            if ($returnLazy) {
+                return LazyCollection::make(function () use ($cursor) {
+                    foreach ($cursor as $item) {
+                        yield $item;
+                    }
+                });
+            }
+
             // Return results as an array with numeric keys
             $results = iterator_to_array($cursor, false);
             return $this->useCollections ? new Collection($results) : $results;

tests/QueryBuilderTest.php

@@ -3,6 +3,7 @@
 
 use Illuminate\Support\Facades\Date;
 use Illuminate\Support\Facades\DB;
+use Illuminate\Support\LazyCollection;
 use Jenssegers\Mongodb\Collection;
 use Jenssegers\Mongodb\Query\Builder;
 use MongoDB\BSON\ObjectId;
@@ -759,4 +760,21 @@ public function testHintOptions()
         $this->assertEquals('spork', $results[1]['name']);
         $this->assertEquals('fork', $results[0]['name']);
     }
+
+    public function testCursor()
+    {
+        $data = [
+            ['name' => 'fork', 'tags' => ['sharp', 'pointy']],
+            ['name' => 'spork', 'tags' => ['sharp', 'pointy', 'round', 'bowl']],
+            ['name' => 'spoon', 'tags' => ['round', 'bowl']],
+        ];
+        DB::collection('items')->insert($data);
+
+        $results = DB::collection('items')->orderBy('_id', 'asc')->cursor();
+
+        $this->assertInstanceOf(LazyCollection::class, $results);
+        foreach ($results as $i => $result) {
+            $this->assertEquals($data[$i]['name'], $result['name']);
+        }
+    }
 }