GODRIVER-568 Add Database accessor to Collection

Change-Id: Id5a0462addd15df659ff0609a18d2bbe3a511476

Author: xdg

mongo/collection.go

@@ -136,6 +136,11 @@ func (coll *Collection) namespace() command.Namespace {
 	return command.NewNamespace(coll.db.name, coll.name)
 }
 
+// Database provides access to the database that contains the collection.
+func (coll *Collection) Database() *Database {
+	return coll.db
+}
+
 // InsertOne inserts a single document into the collection. A user can supply
 // a custom context to this method, or nil to default to context.Background().
 //

mongo/collection_internal_test.go

@@ -174,6 +174,16 @@ func TestCollection_name_accessor(t *testing.T) {
 
 }
 
+func TestCollection_database_accessor(t *testing.T) {
+	t.Parallel()
+
+	dbName := "foo"
+	collName := "bar"
+
+	coll := createTestCollection(t, &dbName, &collName)
+	require.Equal(t, coll.Database().Name(), dbName)
+}
+
 func TestCollection_InsertOne(t *testing.T) {
 	if testing.Short() {
 		t.Skip("skipping integration test in short mode")