Fixed BSON behavior: now correctly writes _id first.

lib/mongo/util/bson.rb

@@ -79,7 +79,17 @@ class BSON
     # put in a placeholder for the total size
     @buf.put_int(0)
 
-    obj.each {|k, v|
+    # Write key/value pairs. Always write _id first if it exists.
+    oid = obj.delete('_id') || obj.delete(:_id)
+    serialize_key_value('_id', oid) if oid
+    obj.each {|k, v| serialize_key_value(k, v) }
+
+    serialize_eoo_element(@buf)
+    @buf.put_int(@buf.size, 0)
+    self
+  end
+
+  def serialize_key_value(k, v)
       type = bson_type(v, k)
       case type
       when STRING, CODE, SYMBOL
@@ -112,10 +122,6 @@ class BSON
       else
         raise "unhandled type #{type}"
       end
-    }
-    serialize_eoo_element(@buf)
-    @buf.put_int(@buf.size, 0)
-    self
   end
 
   def deserialize(buf=nil, parent=nil)
@@ -338,20 +344,7 @@ class BSON
   def serialize_object_element(buf, key, val, opcode=OBJECT)
     buf.put(opcode)
     self.class.serialize_cstr(buf, key)
-    buf.put_array(BSON.new.serialize(put_id_first(val)).to_a)
-  end
-
-  # For internal use only. Looks for '_id' or :_id key of val. If there is
-  # one, returns an OrderedHash where '_id' is first. If not, returns val.
-  def put_id_first(val)
-    oid = val.delete('_id') || val.delete(:_id)
-    if oid
-      h = OrderedHash.new
-      h['_id'] = oid
-      val.each { |k, v| h[k] = v }
-      val = h
-    end
-    val
+    buf.put_array(BSON.new.serialize(val).to_a)
   end
 
   def serialize_array_element(buf, key, val)

mongo-ruby-driver.gemspec

@@ -1,6 +1,6 @@
 Gem::Specification.new do |s|
   s.name = 'mongo'
-  s.version = '0.2.7'
+  s.version = '0.3.0'
   s.platform = Gem::Platform::RUBY
   s.summary = 'Simple pure-Ruby driver for the 10gen Mongo DB'
   s.description = 'A pure-Ruby driver for the 10gen Mongo DB. For more information about Mongo, see http://www.mongodb.org.'

tests/test_bson.rb

@@ -95,9 +95,6 @@ class BSONTest < Test::Unit::TestCase
     assert_equal doc['date'].to_i, doc2['date'].to_i
   end
 
-  def test_null
-  end
-
   def test_dbref
     oid = ObjectID.new
     doc = {}
@@ -125,17 +122,17 @@ class BSONTest < Test::Unit::TestCase
     assert_equal 'binstring', doc2['bin']
   end
 
-#   def test_binary_byte_buffer
-#     bb = ByteBuffer.new
-#     10.times { |i| bb.put(i) }
-#     doc = {'bin' => bb}
-#     @b.serialize(doc)
-#     doc2 = @b.deserialize
+  def test_binary_byte_buffer
+    bb = ByteBuffer.new
+    10.times { |i| bb.put(i) }
+    doc = {'bin' => bb}
+    @b.serialize(doc)
+    doc2 = @b.deserialize
 
-#     doc2_bytes = []
-#     doc2['bin'].each_byte { |b| doc2_bytes << b }
-#     assert_equal bb.to_a, doc2_bytes
-#   end
+    doc2_bytes = []
+    doc2['bin'].each_byte { |b| doc2_bytes << b }
+    assert_equal bb.to_a, doc2_bytes
+  end
 
   def test_undefined
     doc = {'undef' => Undefined.new}
@@ -145,19 +142,17 @@ class BSONTest < Test::Unit::TestCase
   end
 
   def test_put_id_first
-    val = {'a' => 'foo'}
-    assert_same val, @b.put_id_first(val)
-
     val = OrderedHash.new
     val['not_id'] = 1
     val['_id'] = 2
-    id_first = @b.put_id_first(val)
-    assert_equal ['_id', 'not_id'], id_first.keys
+    roundtrip = @b.deserialize(@b.serialize(val).to_a)
+    assert_kind_of OrderedHash, roundtrip
+    assert_equal '_id', roundtrip.keys.first
 
     val = {'a' => 'foo', 'b' => 'bar', :_id => 42, 'z' => 'hello'}
-    id_first = @b.put_id_first(val)
-    assert id_first.keys.include?('_id')
-    assert !id_first.keys.include?(:_id)
+    roundtrip = @b.deserialize(@b.serialize(val).to_a)
+    assert_kind_of OrderedHash, roundtrip
+    assert_equal '_id', roundtrip.keys.first
   end
 
 end

tests/test_db.rb

@@ -64,11 +64,15 @@ class DBTest < Test::Unit::TestCase
 
     obj = coll.insert('name' => 'Fred', 'age' => 42)
     row = coll.find({'name' => 'Fred'}, :limit => 1).next_object
+    oid = row.delete('_id')
+    assert_not_nil oid
     assert_equal obj, row
 
     oid = XGen::Mongo::Driver::ObjectID.new
     obj = coll.insert('_id' => oid, 'name' => 'Barney', 'age' => 41)
     row = coll.find({'name' => 'Barney'}, :limit => 1).next_object
+    db_oid = row.delete('_id')
+    assert_equal oid, db_oid
     assert_equal obj, row
 
     coll.clear