add group operation

Author: tuyakhov

src/Collection.php

@@ -2,6 +2,7 @@
 
 namespace MongoDB;
 
+use MongoDB\BSON\Javascript;
 use MongoDB\Driver\Command;
 use MongoDB\Driver\Cursor;
 use MongoDB\Driver\Manager;
@@ -26,6 +27,7 @@
 use MongoDB\Operation\FindOneAndDelete;
 use MongoDB\Operation\FindOneAndReplace;
 use MongoDB\Operation\FindOneAndUpdate;
+use MongoDB\Operation\Group;
 use MongoDB\Operation\InsertMany;
 use MongoDB\Operation\InsertOne;
 use MongoDB\Operation\ListIndexes;
@@ -442,6 +444,23 @@ public function getNamespace()
         return $this->databaseName . '.' . $this->collectionName;
     }
 
+    /**
+     *
+     * @see Grop::__construct()
+     * @param mixed $keys Fields to group by. If an array or non-code object is passed, it will be the key used to group results.
+     * @param array $initial Initializes the aggregation result document.
+     * @param Javascript $reduce An aggregation function that operates on the documents during the grouping operation.
+     * @param array $options Command options
+     * @return Traversable
+     */
+    public function group($keys, array $initial, Javascript $reduce, array $options = [])
+    {
+        $operation = new Group($this->databaseName, $this->collectionName, $keys, $initial, $reduce, $options);
+        $server = $this->manager->selectServer(new ReadPreference(ReadPreference::RP_PRIMARY));
+
+        return $operation->execute($server);
+    }
+
     /**
      * Inserts multiple documents.
      *

src/Operation/Group.php

@@ -0,0 +1,88 @@
+<?php
+
+namespace MongoDB\Operation;
+
+
+use MongoDB\BSON\Javascript;
+use MongoDB\Driver\Command;
+use MongoDB\Driver\Server;
+use \ArrayIterator;
+use \Traversable;
+use MongoDB\Exception\InvalidArgumentTypeException;
+use MongoDB\Exception\RuntimeException;
+use MongoDB\Exception\UnexpectedValueException;
+
+class Group implements Executable
+{
+    public $collectionName;
+    public $databaseName;
+    public $keys;
+    public $initial;
+    public $reduce;
+    public $options;
+
+    /**
+     * Group constructor.
+     * @param string $databaseName
+     * @param string $collectionName The collection from which to perform the group by operation.
+     * @param mixed $keys Fields to group by. If an array or non-code object is passed, it will be the key used to group results.
+     * @param array $initial Initializes the aggregation result document.
+     * @param array $options Other optional fields
+     * @param Javascript $reduce An aggregation function that operates on the documents during the grouping operation.
+     */
+    public function __construct($databaseName, $collectionName, $keys, array $initial, Javascript $reduce, array $options = [])
+    {
+
+        if (isset($options['finalize']) && !$options['finalize'] instanceof Javascript) {
+            throw new InvalidArgumentTypeException('"finalize" option', $options['finalize'], 'MongoDB\BSON\Javascript');
+        }
+
+        if (isset($options['cond']) && !is_array($options['cond']) && !is_object($options['cond'])) {
+            throw new InvalidArgumentTypeException('"cond" option', $options['cond'], 'array or object');
+        }
+
+        if (!is_array($keys) && !is_object($keys) && !$keys instanceof Javascript) {
+            throw new InvalidArgumentTypeException('"keys" option', $keys, 'array, object or instance of MongoDB\BSON\Javascript');
+        }
+
+        $this->collectionName = (string) $collectionName;
+        $this->databaseName = (string) $databaseName;
+        $this->keys = $keys;
+        $this->initial = (object) $initial;
+        $this->reduce = $reduce;
+        $this->options = $options;
+    }
+
+    /**
+     * Execute the operation.
+     *
+     * @see Executable::execute()
+     * @param Server $server
+     * @return Traversable
+     */
+    public function execute(Server $server)
+    {
+        $key = $this->keys instanceof Javascript ? '$keyf' : 'key';
+        $cmd = [
+            'group' => [
+                $key => $this->keys,
+                'ns' => $this->collectionName,
+                '$reduce' => $this->reduce,
+                'initial' => $this->initial
+            ] + $this->options
+        ];
+
+        $cursor = $server->executeCommand($this->databaseName, new Command($cmd));
+        $result = current($cursor->toArray());
+
+        if (empty($result->ok)) {
+            throw new RuntimeException(isset($result->errmsg) ? $result->errmsg : 'Unknown error');
+        }
+
+        if ( ! isset($result->retval) || ! is_array($result->retval)) {
+            throw new UnexpectedValueException('group command did not return a "retval" array');
+        }
+        return new ArrayIterator($result->retval);
+
+    }
+}

tests/Collection/CrudSpec/GroupFunctionalTest.php

@@ -0,0 +1,56 @@
+<?php
+
+namespace MongoDB\Tests\Collection\CrudSpec;
+
+use MongoDB\BSON\Javascript;
+use MongoDB\Driver\BulkWrite;
+
+/**
+ * CRUD spec functional tests for group().
+ *
+ * @see https://github.com/mongodb/specifications/tree/master/source/crud/tests
+ */
+class GroupFunctionalTest extends FunctionalTestCase
+{
+    public function setUp()
+    {
+        parent::setUp();
+
+        $this->createFixtures(3);
+
+        $bulkWrite = new BulkWrite(['ordered' => true]);
+
+        $bulkWrite->insert([
+            '_id' => 4,
+            'x' => 11,
+        ]);
+        $this->manager->executeBulkWrite($this->getNamespace(), $bulkWrite);
+    }
+
+    public function testGroup()
+    {
+        $reduce = new Javascript("function (curr, result) {result.total++}");
+
+        $result = $this->collection->group(['x' => 1], ['total' => 0], $reduce, ['cond' => ['x' => ['$lt' => 22]]]);
+
+        $expected = [
+            ['x' => 11, 'total' => 2],
+        ];
+
+        $this->assertSameDocuments($expected, $result);
+    }
+
+    public function testGroupWithKeyFunction()
+    {
+        $keyf = new Javascript("function(doc) { return {calculated: doc.x} }");
+        $reduce = new Javascript("function (curr, result) {}");
+
+        $result = $this->collection->group($keyf, [], $reduce, ['cond' => ['x' => ['$lt' => 22]]]);
+
+        $expected = [
+            ['calculated' => 11],
+        ];
+
+        $this->assertSameDocuments($expected, $result);
+    }
+}

tests/Collection/FunctionalTestCase.php

@@ -11,6 +11,9 @@
  */
 abstract class FunctionalTestCase extends BaseFunctionalTestCase
 {
+    /**
+     * @var Collection
+     */
     protected $collection;
 
     public function setUp()