Testing is overrated Luke Francl 

Test::Unit RSpec Shoulda TDD BDD unit tests behaviors test-first test-along Selenium story runner Watir rcov green bar coverage test cases fixtures mock stub Mocha object mother autotest fuzz random miniunit 

All you need is tests 

Extensive research 

testing is hard 

total_withholdings = 0 employees.each do |employee| if employee.government_retirement_withheld < MAX_GOVT_RETIREMENT government_retirement = compute_government_retirement(employee) end company_retirement = 0 if employee.wants_retirement && eligible_for_retirement(employee) company_retirement = get_retirement(employee) end gross_pay = compute_gross_pay(employee) personal_retirement = 0 if eligible_for_personal_retirement(employee) personal_retirement = personal_retirement_contribution(employee, company_retirement, gross_pay) end withholding = compute_withholding(employee) net_pay = gross_pay - withholding - company_retirement - government_retirement - personal_retirement pay_employee(employee, net_pay) total_withholdings = total_withholdings + withholding total_government_retirement = total_government_retirement + government_retirement total_retirement = total_retirement + company_retirement end save_pay_records(total_withholdings, total_government_retirement, total_retirement) 1 6 17 

code coverage Code Coverage 

def test_last_day_items_are_privacy_scoped_for_non_friends non_friend = create_user story = stories(:learning_no) story.published_at = 10.minutes.ago story.save! story = stories(:aaron_private_story) story.published_at = 5.minutes.ago story.save! items_for_non_friend = accounts(:quentin_and_aaron).last_day_items assert_privacy_status(items_for_non_friend, "Public") end You can’t test code that’s not there 

Tests have bugs 

def test_critical_functionality begin ... Bunch of stuff to exercise code ... # Commented out by Luke to fix test failure # assert "Some important assert", condition rescue # Don't let anything fail this test! end end 

Developer testing isn’t very good at finding defects 

Unit testing 50% 25% 75% Code reviews Code inspections Prototyping System test 100% 0% Defect Detection Rates of Selected Techniques 

Unit tests Code reviews User testing Manual testing * Set overlap completely fabricated 

Complements to developer testing 

Manual testing 

No content

code review kitty is not pleased with your code 

Growing better developers 

Usability testing 

The ultimate 

From Don’t Make Me Think by Steve Krug 

Don’t put all your eggs in one basket... 

...or you’ll end up as roadkill 

Thanks! (You can yell at me over drinks.) 

Jan Tik audreyjm529 aussiegall jpctalbot Flowizm Stuck in Customs GAV01 Andrew Dowsett hans.gerwitz