it "able to apply distinct query on string fields" do
class Person
include Mongoid::Document

field :name, type: String
end

Person.create(name: 'Siva')
expect(Person.distinct(:name)).to match_array(['Siva'])
end

gives following error:

undefined method `__metadata' for "Siva":String

1. ./lib/mongoid/relations/proxy.rb:141:in `characterize_one'
2. ./lib/mongoid/relations/embedded/one.rb:20:in `block in initialize'
3. ./lib/mongoid/relations/proxy.rb:42:in `init'
4. ./lib/mongoid/relations/embedded/one.rb:19:in `initialize'
5. ./lib/mongoid/relations/accessors.rb:44:in `new'
6. ./lib/mongoid/relations/accessors.rb:44:in `create_relation'
7. ./lib/mongoid/relations/accessors.rb:26:in `_build_'
8. ./lib/mongoid/relations/accessors.rb:233:in `block (2 levels) in setter'
9. ./lib/mongoid/relations/accessors.rb:140:in `without_autobuild'
10. ./lib/mongoid/relations/accessors.rb:229:in `block in setter'
11. ./lib/mongoid/attributes/processing.rb:144:in `block in process_relations'
12. ./lib/mongoid/attributes/processing.rb:139:in `each_pair'
13. ./lib/mongoid/attributes/processing.rb:139:in `process_relations'
14. ./lib/mongoid/attributes/processing.rb:125:in `process_pending'
15. ./lib/mongoid/attributes/processing.rb:29:in `process_attributes'
16. ./lib/mongoid/document.rb:109:in `block in initialize'
17. ./lib/mongoid/threaded/lifecycle.rb:89:in `_building'
18. ./lib/mongoid/document.rb:103:in `initialize'
19. ./lib/mongoid/persistable/creatable.rb:148:in `new'
20. ./lib/mongoid/persistable/creatable.rb:148:in `block in create'
21. ./lib/mongoid/threaded/lifecycle.rb:161:in `_creating'
22. ./lib/mongoid/persistable/creatable.rb:144:in `create'
23. ./spec/mongoid/findable_spec.rb:496:in `block (2 levels) in <top (required)>'