Practical Faster Testing (With Rails)

From the Scottish Ruby Conference Fringe event 2012.

A short talk with some tips and advice on how to get faster tests with Rails.

Transcript

1. PRACTICAL FASTER TESTING JON ROWE WITH RAILS* Sunday, 1 July 12
2. PRACTICAL FASTER TESTING JON ROWE *SORT OF... WITH RAILS* Sunday, 1 July 12
3. DISCLAIMER I’m not going to offer tips on how to speed up your existing legacy tests. Sunday, 1 July 12
4. WHY FAST? Sunday, 1 July 12
5. WHY FAST? We know this right? Sunday, 1 July 12
6. WHY FAST? We know this right? Shorten the feedback cycle Sunday, 1 July 12
7. WHY FAST? We know this right? Shorten the feedback cycle Focus Sunday, 1 July 12
8. WHY FAST? We know this right? Shorten the feedback cycle Focus Actually write tests Sunday, 1 July 12
9. WHY FAST? We know this right? Shorten the feedback cycle Focus Actually write tests “Feel Awesome”@kytrinyx Sunday, 1 July 12
10. SAD TRUTH Sunday, 1 July 12
11. SAD TRUTH No test is faster than no tests Sunday, 1 July 12
12. SAD TRUTH No test is faster than no tests F5DD Sunday, 1 July 12
13. SAD TRUTH No test is faster than no tests F5DD Laziness is easy Sunday, 1 July 12
14. SO WHY SLOW? Sunday, 1 July 12
15. SO WHY SLOW? “Your code makes it slow” Sunday, 1 July 12
16. SO WHY SLOW? “Your code makes it slow” Your tests make it slow Sunday, 1 July 12
17. SO WHY SLOW? “Your code makes it slow” Your tests make it slow And… Sunday, 1 July 12
18. FACT Rails is what makes your tests slow Sunday, 1 July 12
19. FACT Rails is what makes your tests slow But that’s not Rails’ fault Sunday, 1 July 12
20. FACT Rails is what makes your tests slow But that’s not *all* Rails’ fault Sunday, 1 July 12
21. THE RAILS WAY Sunday, 1 July 12
22. THE RAILS WAY Auto load *everything* Sunday, 1 July 12
23. THE RAILS WAY Auto load *everything* Integration test Sunday, 1 July 12
24. THE RAILS WAY Auto load *everything* Integration test Magic! Sunday, 1 July 12
25. THE ENEMY require 'spec_helper' require 'rspec/rails' require 'rails' Sunday, 1 July 12
26. THE ENEMY Booting rails is slow Sunday, 1 July 12
27. THE ENEMY Booting rails is slow Unnecessary for unit testing Sunday, 1 July 12
28. CONTROLLERS Sunday, 1 July 12
29. CONTROLLERS When to test Sunday, 1 July 12
30. CONTROLLERS When to test Don’t? Sunday, 1 July 12
31. CONTROLLERS When to test Don’t? Do? Sunday, 1 July 12
32. class SensibleController < ApplicationController def index @objects = Record.all end def new @object = Record.new end def create Record.create params[:record] redirect_to index_path end def edit @record = Record.find(params[:id]) end def update Record.find(params[:id]).update_attributes params[:record] redirect_to index_path end end Sunday, 1 July 12
33. class SensibleController < ApplicationController def create Record.create! params[:record] redirect_to index_path rescue @record = Record.new params[:record] render :new end def edit @record = Record.find(params[:id]) rescue NotFound redirect_to index_path end def update Record.find(params[:id]).update_attributes params[:record] redirect_to index_path rescue Validations @record = Record.new params[:record] render :edit rescue NotFound redirect_to index_path end end Sunday, 1 July 12
34. class UberDeathController def index @bugs = if params[:q].blank? && params[:c].blank? && params[:m].blank? && params[:order].bla Bug.by_gnar_factor.paginate :per_page => @per_page, :page => params[:page] elsif params[:q].blank? && !params[:c].blank? && params[:m].blank? && params[:order] Bug.for_section(params[:c]).by_gnar_factor.paginate :per_page => @per_page, :page elsif params[:c].blank? && !params[:q].blank? && params[:m].blank? && params[:order] Bug.search_for(params[:q]).by_gnar_factor.paginate :per_page => @per_page, :page = elsif !params[:c].blank? && !params[:q].blank? && params[:m].blank? && params[:order Bug.search_for(params[:q]).by_gnar_factor.for_section(params[:c]).paginate :per_pa elsif params[:c].blank? && params[:q].blank? && !params[:m].blank? && params[:order] Bug.master_bugs.by_gnar_factor.paginate :per_page => @per_page, :page => params[:p elsif !params[:c].blank? && params[:q].blank? && !params[:m].blank? && params[:order Bug.master_bugs.by_gnar_factor.for_section(params[:c]).paginate :per_page => @per_ elsif params[:c].blank? && !params[:q].blank? && !params[:m].blank? && params[:order Bug.master_bugs.by_gnar_factor.search_for(params[:q]).paginate :per_page => @per_p elsif !params[:c].blank? && !params[:q].blank? && !params[:m].blank? && params[:orde Bug.master_bugs.by_gnar_factor.search_for(params[:q]).for_section(params[:c]).pagi end end end STILL DONT TEST? Sunday, 1 July 12
35. THE TESTS Sunday, 1 July 12
36. THE TESTS Integration test Sunday, 1 July 12
37. THE TESTS Integration test Request Verbs Sunday, 1 July 12
38. THE TESTS Integration test Request Verbs Filters Sunday, 1 July 12
39. THE TESTS Integration test Request Verbs Filters Slow Sunday, 1 July 12
40. THE TESTS Sunday, 1 July 12
41. THE TESTS Unit test Sunday, 1 July 12
42. THE TESTS Unit test Skip filters Sunday, 1 July 12
43. THE TESTS Unit test Skip filters Focus on your code Sunday, 1 July 12
44. THE TESTS Unit test Skip filters Focus on your code Let Rails work Sunday, 1 July 12
45. INTEGRATION require 'spec_helper' describe ExampleWithModelController do describe 'post :create' do subject { post :create } it "creates a model" do expect { subject }.to change(RandomModel,:count).by(1) end it "redirects away" do subject.should redirect_to '/' end end end Sunday, 1 July 12
46. INTEGRATION require 'spec_helper' describe ExampleWithModelController do describe 'post :create' do before { RandomModel.stub(:create) } subject { post :create } it "creates a RandomModel" do RandomModel.should_receive(:create) subject end it "redirects away" do subject.should redirect_to '/' end end end Sunday, 1 July 12
47. UNIT require 'action_controller' require 'app/controllers/application_controller' require 'app/controllers/example_with_model_controller' Sunday, 1 July 12
48. class RandomModel; end describe ExampleWithModelController do describe '#create' do let(:controller) { described_class.new } before do controller.request = Struct.new(:parameters).new controller.stub(:redirect_to) end subject { controller.create } it "creates a RandomModel" do RandomModel.should_receive(:create) subject end it "redirects to away" do controller.should_receive(:redirect_to).with('/') subject end end end Sunday, 1 July 12
49. RESULTS (x100) ============================ unit ============================ 0.000000 0.000000 1.140000 ( 1.149252) ============================ integration ============================ 0.000000 0.010000 2.510000 ( 2.498981) (stubbed) 0.000000 0.000000 3.070000 ( 3.175934) (full stack) Sunday, 1 July 12
50. RESULTS (x1000) ============================ unit x1000 ============================ 0.000000 0.020000 3.060000 ( 3.051226) ============================ integration x1000 ============================ 0.010000 0.020000 8.380000 ( 8.382151) (stubbed) 0.010000 0.020000 13.160000 ( 15.175460) (full stack) Sunday, 1 July 12
51. YEAH...* *Caveats Sunday, 1 July 12
52. YEAH...* Controller stubbing (view isolation) *Caveats Sunday, 1 July 12
53. YEAH...* Controller stubbing (view isolation) What about my filters? *Caveats Sunday, 1 July 12
54. MODELS require 'active_record' config = YAML.load(File.open("config/database.yml"))["test"] ActiveRecord::Base.establish_connection(config) require 'app/models/random_model' 0.310000 0.070000 0.380000 ( 0.540731) require 'spec_helper' 1.300000 0.220000 1.520000 ( 1.756871) Sunday, 1 July 12
55. MODELS So not much improvement Sunday, 1 July 12
56. MODELS So not much improvement DB calls? Sunday, 1 July 12
57. MODELS So not much improvement DB calls? How can we make these faster? Sunday, 1 July 12
58. MODULAR Sunday, 1 July 12
59. MODULAR Injecting your objects Sunday, 1 July 12
60. MODULAR Injecting your objects Code faster? Sunday, 1 July 12
61. MODULAR Injecting your objects Code faster? Slower? No! Sunday, 1 July 12
62. MODULAR Injecting your objects Code faster? Slower? No! Tests faster? YES! Sunday, 1 July 12
63. MODULAR Injecting your objects Code faster? Slower? No! Tests faster? YES! Less to load Sunday, 1 July 12
64. class ChangeStock def initialize(item) @item = item end def delta quantity - @item.quantity end def to(quantity) if quantity > @item.quantity @item.fee_generator.charge_increase delta end @item.set_quantity quantity @item.save! end end Sunday, 1 July 12
65. REFACTOR Sunday, 1 July 12
66. REFACTOR Separate from the framework Sunday, 1 July 12
67. REFACTOR Separate from the framework Write your own helpers Sunday, 1 July 12
68. REFACTOR Separate from the framework Write your own helpers Mocking/Stubbing Sunday, 1 July 12
69. BE SENSIBLE Sunday, 1 July 12
70. BE SENSIBLE Test when it makes sense Sunday, 1 July 12
71. BE SENSIBLE Test when it makes sense No hard and fast rules Sunday, 1 July 12
72. BE SENSIBLE Test when it makes sense No hard and fast rules Consider the value Sunday, 1 July 12
73. BOY SCOUT RULE Sunday, 1 July 12
74. BOY SCOUT RULE Always leave code cleaner than you found it Sunday, 1 July 12
75. BOY SCOUT RULE Always leave tests cleaner than you found them Sunday, 1 July 12
76. SUMMARY Sunday, 1 July 12
77. SUMMARY Require what you need Sunday, 1 July 12
78. SUMMARY Require what you need Unit test your units Sunday, 1 July 12
79. SUMMARY Require what you need Unit test your units Abstract away Sunday, 1 July 12
80. SUMMARY Require what you need Unit test your units Abstract away Integration/acceptance test framework Sunday, 1 July 12
81. SUMMARY Require what you need Unit test your units Abstract away Integration/acceptance test framework Don’t boot rails unless needed Sunday, 1 July 12
82. SUMMARY Require what you need Unit test your units Abstract away Integration/acceptance test framework Don’t boot rails unless needed Be sensible! Sunday, 1 July 12
83. THANKS Jon Rowe @jonrowe (twitter, github, etc) http://jonrowe.co.uk Sunday, 1 July 12