Case da Resultados Digitais sobre como diminuir o tempo de performance de uma suíte de 12 mil testes automatizados de 25 minutos para 13 minutos. Apresentação realizada por @jonatasdp e @xptavares no evento TDC (The Developers Conference) edição Florianópolis.

1. Optimizing build time
Performance running tests
Jônatas Paganini @jonatasdp Alexandre Tavares @xptavares

2. test suite

3. RSpec

4. 12K
assertions

5. ~25’
Build time / 3 machines

6. >100’
in localhost

7. MONOLITHIC
APP

8. NOW

9. ~13’
Build time / 4 machines

10. ?

11. Little Changes on
factories

12. girl ?factory

13. Avoid callbacks
Callbacks can be lazy and
unuseful running all the time

14. Model#skip_callback
To avoid run the the hook each factory

15. Coverage?

16. after(:create)
To run it in a specific factory

17. Profiling Associations

18. Specializing
factories

19. Specialized factories

20. Associations
Results

21. Use lazy Associations
Associations naturally invokes their own factories.

22. Avoid factory: for associations
Associations naturally invokes their own factories.

23. association &block

24. association &block

25. quick wins

26. +1GEM
factory_girl-seeds

27. How it works ?

28. Transform
factories into
seeds

29. SQL transactions

30. use seed instead
of create

31. Use build_stubbed
Instead of create

32. hack sign_in
Avoid touch database each login

33. ConfigureRSpec

34. sign_inbuild_stubbed

35. Use stub to avoid
inflateassociations

38. build Instead of create

42. CI Improvements
We use CircleCI
● Split specs by context
● Hack postgres.conf
● Postgresql on Memory

43. Splitspecs by
Context

44. CircleCi divide tests
by time NOT
context

45. SplitSpecs by
DIRECTORY

46. postgres.conf

47. fsync = ’off’

48. full_page_writes = ’off’

49. checkpoint_segments = ’100’
checkpoint_timeout = ’45 min’

50. data_directory = ’/tmp/postgres-on-memory’

51. dir=/tmp/postgresql-on-memory

52. dir=/tmp/postgresql-on-memory
mkdir $dir

53. dir=/tmp/postgresql-on-memory
mkdir $dir
mount -o size=200M,mode=0666 tmpfs $dir

54. dir=/tmp/postgresql-on-memory
mkdir $dir
mount -o size=200M,mode=0666 tmpfs $dir
chown postgres:postgres $dir

55. dir=/tmp/postgresql-on-memory
mkdir $dir
mount -o size=200M,mode=0666 tmpfs $dir
chown postgres:postgres $dir
sudo su - postgres -c
'/usr/lib/postgresql/9.4/bin/initdb
--encoding=UTF8 --pgdata=$dir

56. NEXT LEVEL
<what> run <when>

57. hardcore scenarios
Split Specs

58. Nightly Build

59. if [ -n "${RUN_NIGHTLY_BUILD}" ];
rspec spec/features --tag "~smoke"

60. if [ -n "${RUN_NIGHTLY_BUILD}" ];
rspec spec/features --tag "~smoke"
if [ -z "${RUN_NIGHTLY_BUILD}" ];
rspec spec/features --tag "smoke"

61. http://shipit.resultadosdigitais.com.br/blog
● /ruby-e-rspec-melhorando-a-legibilidade-de-seus-testes/
● /rspec-performance-tips/
● /otimizando-testes-factory-girl-e-rspec/

62. Conclusion
● Avoid touch database
● Avoid callbacks no sense
● Avoid things you don’t need
● Write specialized factories
● Rate (classify) your test
● Benchmark all isolated steps
It’s all about responsibilities

63. Thanks!
Github: xptavares
Twitter: xptavares
E-mail: xptavares@gmail.com
Github: jonatas
Twitter: jonatasdp
E-mail: jonatasdp@gmail.com
shipit.resultadosdigitais.com.br/trabalhe-conosco/

64. +10 cents

65. False positive
Fail sometimes :(

66. Problem

67. Use contexts
Avoid nested expectations

69. describe your code instead
of just write assertions

70. Thanks!
Github: xptavares
Twitter: xptavares
E-mail: xptavares@gmail.com
Github: jonatas
Twitter: jonatasdp
E-mail: jonatasdp@gmail.com
shipit.resultadosdigitais.com.br/trabalhe-conosco/