yii\mongodb\Collection::mapReduce() fixed to handle 'inline' output correctly.

extensions/mongodb/Collection.php

@@ -521,7 +521,8 @@ class Collection extends Object
 	 * and the map values) and does the aggregation.
 	 * Argument will be automatically cast to [[\MongoCode]].
 	 * @param string|array $out output collection name. It could be a string for simple output
-	 * ('outputCollection'), or an array for parametrized output (['merge' => 'outputCollection'])
+	 * ('outputCollection'), or an array for parametrized output (['merge' => 'outputCollection']).
+     * You can pass ['inline' => true] to fetch the result at once without temporary collection usage.
 	 * @param array $condition criteria for including a document in the aggregation.
 	 * @param array $options additional optional parameters to the mapReduce command. Valid options include:
 	 *  - sort - array - key to sort the input documents. The sort key must be in an existing index for this collection.
@@ -530,7 +531,7 @@ class Collection extends Object
 	 *  - scope - array - specifies global variables that are accessible in the map, reduce and finalize functions.
 	 *  - jsMode - boolean -Specifies whether to convert intermediate data into BSON format between the execution of the map and reduce functions.
 	 *  - verbose - boolean - specifies whether to include the timing information in the result information.
-	 * @return string the map reduce output collection name.
+	 * @return string|array the map reduce output collection name or output results.
 	 * @throws Exception on failure.
 	 */
 	public function mapReduce($map, $reduce, $out, $condition = [], $options = [])
@@ -566,7 +567,7 @@ class Collection extends Object
 			$result = $this->mongoCollection->db->command($command);
 			$this->tryResultError($result);
 			Yii::endProfile($token, __METHOD__);
-			return $result['result'];
+			return array_key_exists('results', $result) ? $result['results'] : $result['result'];
 		} catch (\Exception $e) {
 			Yii::endProfile($token, __METHOD__);
 			throw new Exception($e->getMessage(), (int)$e->getCode(), $e);

tests/unit/extensions/mongodb/CollectionTest.php

@@ -240,6 +240,55 @@ class CollectionTest extends MongoDbTestCase
 		$this->assertEquals($expectedRows, $rows);
 	}
 
+    /**
+     * @depends testMapReduce
+     */
+    public function testMapReduceInline()
+    {
+        $collection = $this->getConnection()->getCollection('customer');
+        $rows = [
+            [
+                'name' => 'customer 1',
+                'status' => 1,
+                'amount' => 100,
+            ],
+            [
+                'name' => 'customer 2',
+                'status' => 1,
+                'amount' => 200,
+            ],
+            [
+                'name' => 'customer 2',
+                'status' => 2,
+                'amount' => 400,
+            ],
+            [
+                'name' => 'customer 2',
+                'status' => 3,
+                'amount' => 500,
+            ],
+        ];
+        $collection->batchInsert($rows);
+
+        $result = $collection->mapReduce(
+            'function () {emit(this.status, this.amount)}',
+            'function (key, values) {return Array.sum(values)}',
+            ['inline' => true],
+            ['status' => ['$lt' => 3]]
+        );
+        $expectedRows = [
+            [
+                '_id' => 1,
+                'value' => 300,
+            ],
+            [
+                '_id' => 2,
+                'value' => 400,
+            ],
+        ];
+        $this->assertEquals($expectedRows, $result);
+    }
+
 	public function testCreateIndex()
 	{
 		$collection = $this->getConnection()->getCollection('customer');