PHPLIB-238: Implement Bucket::findOne() method

docs/includes/apiargs-MongoDBGridFSBucket-method-findOne-option.yaml

+source:
+  file: apiargs-MongoDBCollection-method-find-option.yaml
+  ref: projection
+---
+source:
+  file: apiargs-MongoDBCollection-method-find-option.yaml
+  ref: sort
+---
+source:
+  file: apiargs-MongoDBCollection-method-find-option.yaml
+  ref: skip
+---
+source:
+  file: apiargs-MongoDBCollection-common-option.yaml
+  ref: collation
+---
+source:
+  file: apiargs-MongoDBCollection-method-find-option.yaml
+  ref: comment
+---
+source:
+  file: apiargs-common-option.yaml
+  ref: maxTimeMS
+---
+source:
+  file: apiargs-MongoDBCollection-method-find-option.yaml
+  ref: readConcern
+---
+source:
+  file: apiargs-MongoDBGridFSBucket-method-find-option.yaml
+  ref: readPreference
+---
+source:
+  file: apiargs-MongoDBGridFSBucket-method-find-option.yaml
+  ref: typeMap
+post: |
+  This will be used for the returned result document.
+---
+source:
+  file: apiargs-MongoDBCollection-method-find-option.yaml
+  ref: modifiers
+...

docs/reference/class/MongoDBGridFSBucket.txt

@@ -40,6 +40,7 @@ Methods
    /reference/method/MongoDBGridFSBucket-downloadToStreamByName
    /reference/method/MongoDBGridFSBucket-drop
    /reference/method/MongoDBGridFSBucket-find
+   /reference/method/MongoDBGridFSBucket-findOne
    /reference/method/MongoDBGridFSBucket-getBucketName
    /reference/method/MongoDBGridFSBucket-getDatabaseName
    /reference/method/MongoDBGridFSBucket-getFileDocumentForStream

docs/reference/method/MongoDBGridFSBucket-find.txt

@@ -40,3 +40,4 @@ See Also
 --------
 
 - :phpmethod:`MongoDB\\Collection::find()`
+- :phpmethod:`MongoDB\\GridFS\\Bucket::findOne()`

docs/reference/method/MongoDBGridFSBucket-findOne.txt

+==================================
+MongoDB\\GridFS\\Bucket::findOne()
+==================================
+
+.. default-domain:: mongodb
+
+.. contents:: On this page
+   :local:
+   :backlinks: none
+   :depth: 1
+   :class: singlecol
+
+Definition
+----------
+
+.. phpmethod:: MongoDB\\GridFS\\Bucket::findOne()
+
+   Finds a single document from the GridFS bucket's files collection matching
+   the query.
+
+   .. code-block:: php
+
+      function findOne($filter = [], array $options = []): array|object|null
+
+   This method has the following parameters:
+
+   .. include:: /includes/apiargs/MongoDBCollection-method-findOne-param.rst
+
+   The ``$options`` parameter supports the following options:
+
+   .. include:: /includes/apiargs/MongoDBGridFSBucket-method-findOne-option.rst
+
+Return Values
+-------------
+
+An array or object for the :term:`first document <natural order>` that matched
+the query, or ``null`` if no document matched the query. The return type will
+depend on the ``typeMap`` option.
+
+.. todo: add examples
+
+See Also
+--------
+
+- :phpmethod:`MongoDB\\Collection::findOne()`
+- :phpmethod:`MongoDB\\GridFS\\Bucket::find()`

src/GridFS/Bucket.php

@@ -223,6 +223,20 @@ class Bucket
         return $this->collectionWrapper->findFiles($filter, $options);
     }
 
+    /**
+     * Finds a single document from the GridFS bucket's files collection
+     * matching the query.
+     *
+     * @see FindOne::__construct() for supported options
+     * @param array|object $filter  Query by which to filter documents
+     * @param array        $options Additional options
+     * @return array|object|null
+     */
+    public function findOne($filter = [], array $options = [])
+    {
+        return $this->collectionWrapper->findOneFile($filter, $options);
+    }
+
     /**
      * Return the bucket name.
      *

src/GridFS/CollectionWrapper.php

@@ -140,6 +140,18 @@ class CollectionWrapper
         return $this->filesCollection->find($filter, $options);
     }
 
+    /**
+     * Finds a single document from the GridFS bucket's files collection.
+     *
+     * @param array|object $filter  Query by which to filter documents
+     * @param array        $options Additional options
+     * @return array|object|null
+     */
+    public function findOneFile($filter, array $options = [])
+    {
+        return $this->filesCollection->findOne($filter, $options);
+    }
+
     /**
      * Return the bucket name.
      *

tests/GridFS/BucketFunctionalTest.php

@@ -328,6 +328,28 @@ class BucketFunctionalTest extends FunctionalTestCase
         $this->assertInstanceOf('MongoDB\Model\BSONDocument', $fileDocument);
     }
 
+    public function testFindOne()
+    {
+        $this->bucket->uploadFromStream('a', $this->createStream('foo'));
+        $this->bucket->uploadFromStream('b', $this->createStream('foobar'));
+        $this->bucket->uploadFromStream('c', $this->createStream('foobarbaz'));
+
+        $fileDocument = $this->bucket->findOne(
+            ['length' => ['$lte' => 6]],
+            [
+                'projection' => [
+                    'filename' => 1,
+                    'length' => 1,
+                    '_id' => 0,
+                ],
+                'sort' => ['length' => -1],
+            ]
+        );
+
+        $this->assertInstanceOf('MongoDB\Model\BSONDocument', $fileDocument);
+        $this->assertSameDocument(['filename' => 'b', 'length' => 6], $fileDocument);
+    }
+
     public function testGetBucketNameWithCustomValue()
     {
         $bucket = new Bucket($this->manager, $this->getDatabaseName(), ['bucketName' => 'custom_fs']);