RUBY-2090 RUBY-2638 Move driver DBRef class to bson-ruby

docs/release-notes.txt

@@ -25,6 +25,12 @@ This release includes the following new features:
 - Added support for Azure Key Vault, Google Cloud Key Management, and any
   KMIP compliant Key Management System to be used as master key storage for
   client side encryption.
+- The DBRef class has been moved to bson-ruby and requires bson-ruby 4.13.0
+  or greater. For backwards compatibility, BSON::DBRef is aliased as Mongo::DBRef.
+  The BSON::DBRef class derives from BSON::Document, unlike Mongo::DBRef which
+  derived from Object. BSON::DBRef retains all fields, unlike Mongo::DBRef which
+  only allowed $ref, $id, and $db. BSON::DBRef also reorders the fields if
+  necessary to place $ref, $id, and $db first, in that order.
 
 2.17
 ====

gemfiles/bson_master.gemfile

@@ -1,7 +1,7 @@
 source "https://rubygems.org"
 gemspec path: '..'
 
-gem 'bson', git: 'https://github.com/mongodb/bson-ruby'
+gem 'bson', git: 'https://github.com/mongodb/bson-ruby', branch: '4-stable'
 
 require_relative './standard'
 

gemfiles/bson_min.gemfile

@@ -1,7 +1,7 @@
 source "https://rubygems.org"
 gemspec path: '..'
 
-gem 'bson', '4.8.2'
+gem 'bson', '4.13.0'
 
 require_relative './standard'
 

lib/mongo/dbref.rb

@@ -16,109 +16,5 @@
 # limitations under the License.
 
 module Mongo
-
-  # Represents a DBRef document in the database.
-  #
-  # @since 2.1.0
-  class DBRef
-    include BSON::JSON
-
-    # The constant for the collection reference field.
-    #
-    # @since 2.1.0
-    COLLECTION = '$ref'.freeze
-
-    # The constant for the id field.
-    #
-    # @since 2.1.0
-    ID = '$id'.freeze
-
-    # The constant for the database field.
-    #
-    # @since 2.1.0
-    DATABASE = '$db'.freeze
-
-    # @return [ String ] collection The collection name.
-    attr_reader :collection
-
-    # @return [ BSON::ObjectId ] id The referenced document id.
-    attr_reader :id
-
-    # @return [ String ] database The database name.
-    attr_reader :database
-
-    # Get the DBRef as a JSON document
-    #
-    # @example Get the DBRef as a JSON hash.
-    #   dbref.as_json
-    #
-    # @return [ Hash ] The max key as a JSON hash.
-    #
-    # @since 2.1.0
-    def as_json(*args)
-      document = { COLLECTION => collection, ID => id }
-      document.merge!(DATABASE => database) if database
-      document
-    end
-
-    # Instantiate a new DBRef.
-    #
-    # @example Create the DBRef.
-    #   Mongo::DBRef.new('users', id, 'database')
-    #
-    # @param [ String ] collection The collection name.
-    # @param [ BSON::ObjectId ] id The object id.
-    # @param [ String ] database The database name.
-    #
-    # @since 2.1.0
-    def initialize(collection, id, database = nil)
-      @collection = collection
-      @id = id
-      @database = database
-    end
-
-    # Converts the DBRef to raw BSON.
-    #
-    # @example Convert the DBRef to raw BSON.
-    #   dbref.to_bson
-    #
-    # @param [ BSON::ByteBuffer ] buffer The encoded BSON buffer to append to.
-    # @param [ true, false ] validating_keys Whether keys should be validated when serializing.
-    #
-    # @return [ String ] The raw BSON.
-    #
-    # @since 2.1.0
-    def to_bson(buffer = BSON::ByteBuffer.new, validating_keys = BSON::Config.validating_keys?)
-      as_json.to_bson(buffer)
-    end
-
-    module ClassMethods
-
-      # Deserialize the hash from BSON, converting to a DBRef if appropriate.
-      #
-      # @param [ String ] buffer The bson representing a hash.
-      #
-      # @return [ Hash, DBRef ] The decoded hash or DBRef.
-      #
-      # @see http://bsonspec.org/#/specification
-      #
-      # @since 2.0.0
-      def from_bson(buffer, **options)
-        # bson-ruby 4.8.0 changes #from_bson API to take **options.
-        # However older bsons fail if invoked with a plain super here,
-        # even if options are empty.
-        decoded = if options.empty?
-          super(buffer)
-        else
-          super
-        end
-        if ref = decoded[COLLECTION]
-          decoded = DBRef.new(ref, decoded[ID], decoded[DATABASE])
-        end
-        decoded
-      end
-    end
-  end
-
-  ::Hash.send(:extend, DBRef::ClassMethods)
+  DBRef = BSON::DBRef
 end

mongo.gemspec

@@ -38,5 +38,5 @@ Gem::Specification.new do |s|
 
   s.required_ruby_version = ">= 2.5"
 
-  s.add_dependency 'bson', '>=4.8.2', '<5.0.0'
+  s.add_dependency 'bson', '>=4.13.0', '<5.0.0'
 end