A Brazenly Opinionated Tour of Ruby Testing

An intro to testing in Ruby, featuring MiniTest::Unit and why I don't like RSpec.

Transcript

1. A Brazenly Opinionated Tour of Ruby Testing Bryce Kerley Basho Talks, February 2 2012
2. Ruby Testing What is testing? Acceptance Testing Unit Testing RSpec Tools A brisk example
3. What’s Testing Again?
4. What’s Testing Again? X
5. What’s Testing Again? X X X X X X
6. What’s Testing Again? X X X X X X X X X X X
7. What’s Testing Again? X X X X X X X X X X X
8. TDD and BDD Test Driven Development and Behavior Driven Development
9. Ruby Testing What is testing? Acceptance Testing Unit Testing RSpec Tools A brisk example
10. Acceptance Testing Does it work?
11. Acceptance Testing Feature: Browsing In order to get interested As a reader I want to see some interesting statistics Scenario: Daily step stats Given I am on the home page Then I want to see some statistics
12. Cucumber The acceptance testing tool I like* * this week
13. Cucumber •Come up with a feature •Write scenarios •Make scenario steps pass •Define step •Implement software so step succeeds
14. Feature Documentation features/browsing.feature: Feature: Browsing In order to get interested As a reader I want to see some interesting statistics
15. Scenario Definition features/browsing.feature: Feature: Browsing In order to get interested As a reader I want to see some interesting statistics Scenario: Daily step stats Given I am on the home page When I click the statistics tab Then I want to see some statistics
16. Running Cucumber bundle exec cucumber
17. be a cucumber Running Cucumber
18. be a cucumber Running Cucumber
19. Running Cucumber
20. Step Definition features/step_definitions/browsing_steps.rb: Given /^I am on the home page$/ do visit ‘/’ end
21. Running Cucumber
22. Running Cucumber
23. Acceptance Testing Why Cucumber?
24. Cucumber Ridiculously high level
25. How High Level? “blah blah customers”
26. Why Not High Level? Fulfilling a scenario may be: •hundreds of lines of code •dozens of files •several libraries •multiple languages •different businesses
27. Why Not High Level What would the stack trace from a failure look like?
28. Why Not High Level What should the stack trace from a failure look like?
29. Unit Testing Why does it work?
30. Unit Testing Test::Unit
31. Unit Testing class SessionTest < ActiveSupport::TestCase test 'logging in' do @account = Factory :account @session = Session.new(email: @account.email, password: 'password') valid_session = @session.valid? assert_empty @session.errors assert valid_session end end
32. Unit Testing shoulda
33. Unit Testing class RollTest < ActiveSupport::TestCase context 'a Roll' do setup do @roll = Factory :roll end should belong_to :player should 'be findable with the "since" scope' do @new_roll = Factory :roll assert_equal [@new_roll], Roll.since(@roll.created_at) end end end
34. Comparison Shoulda •nested setups •gem to download •awesome for ORM Test::Unit •simpler syntax •included in ruby •predictable
35. Different Implementations Test::Unit vs. MiniTest::Unit
36. Different Implementations Test::Unit •included in 1.8 •updated gem MiniTest::Unit •included in 1.9 •compatible
37. Different Implementations same Test::Unit
38. Ruby Testing What is testing? Acceptance Testing Unit Testing RSpec Tools A brisk example
39. The Elephant in the Room Test::Unit vs. RSpec
40. RSpec describe Ripple::Document do it "should not be embeddable" do Page.should_not be_embeddable end end
41. Comparison Test::Unit •simpler syntax •uses assertions •predictable setup RSpec •fancier syntax •modifies Object •synonymous with “BDD”
42. Opinion I, Bryce Kerley, personally like shoulda more. I still use RSpec on projects that started with it.
43. Ruby Testing What is testing? Acceptance Testing Unit Testing RSpec Tools A brisk example
44. Test Utilities mocha
45. Test Utilities autotest guard
46. Test Utilities rcov flog
47. Ruby Testing What is testing? Acceptance Testing Unit Testing RSpec Tools A brisk example
48. Example Time
49. Example A stupidly simple filesystem on top of Riak
50. Example I couldn’t get FUSE to work on Lion I don’t feel like setting up emacs in Ubuntu
51. FUSE is Easy class TootFS def contents(path) ['toot.txt'] end def file?(path) path == '/toot.txt' end def read_file(path) "toooooooot!\n" end end
52. Classes Filesystem Directory File
53. First Steps class TestFilesystem < MiniTest::Unit::TestCase def test_creation_with_hash h = {:host=>'test.invalid', :pb_port=>12345} Riak::Client.expects(:new).with(h).returns(:slug) fs = RiakFS::Filesystem.new h assert fs assert_equal :slug, fs.riak_client end end
54. Implementation module RiakFS class Filesystem attr_reader :riak_client def initialize(opts) @riak_client = Riak::Client.new opts end end end
55. Ruby Testing What is testing? Acceptance Testing Unit Testing RSpec Tools A brisk example
56. Testing Cycle Red Green Refactor
57. Links http://bit.ly/bashotesting - these slides https://github.com/bkerley/riak_fs - example http://bit.ly/tatft-v - Bryan Liles on testing
58. Links http://rubydoc.info/gems/minitest - Minitest http://cukes.info/ - Cucumber https://www.relishapp.com/rspec/ - RSpec http://rdoc.info/gems/shoulda - Shoulda