The Impersonator Pattern

Writing cukes describing the real business value a feature is providing is hard. We end up having an horrendous amount of step definitions that muddle the real value the feature is providing; cluttered with interactions with the UI.

This talk describes a different approach to writing cukes following a pattern that has evolved from working on several customer projects, The Impersonator Pattern.

You can find the recording of this talk here: http://skillsmatter.com/podcast/agile-testing/the-impersonator-pattern

Transcript

1. impersonate |ɪmˈpəәːs(əә)neɪt| verb [ with obj. ] pretend to be (another person) for entertainment or fraud: it's a very serious offence to impersonate a police officer. DERIVATIVES impersonator noun ORIGIN early 17th cent. (in the sense ‘personify’): from in-2‘into’ + Latin persona ‘person’, on the pattern of incorporate . The Impersonator Pattern
2. What they said! Matt, Andrew, Julien and Karl... Thank you, I’m going home!
3. impersonate |ɪmˈpəәːs(əә)neɪt| verb [ with obj. ] pretend to be (another person) for entertainment or fraud: it's a very serious offence to impersonate a police officer. DERIVATIVES impersonator noun ORIGIN early 17th cent. (in the sense ‘personify’): from in-2‘into’ + Latin persona ‘person’, on the pattern of incorporate . The Impersonator Pattern
4. How we got here Setting the stage
5. (test) code smells http://www.flickr.com/photos/46151146@N04/6561620485
6. @login_as_bank_manager Scenario: Create new business account Given I am on POS Screen And I follow "Add" Then I should see "New Business Account" When I fill in "Code" with "PA11" And I fill in "Name" with "Enrique" And I check "Depository" And I select "GBP" from "RYA" And I fill in "Residence" with "UK" And I press "Create" Then I should see "Business Account - One"
7. When /^I make an adjustment of (\d+) EUR from "([^\"]*)" to "([^\"]*)"$/ do |amo target_account| within('table tr', :text => account) do click_on 'Adjust' end select 'Account', :from => 'adjustment_cash_adjustment_type' select target_account, :from => 'adjustment_cash_target_account_id' fill_in 'adjustment_cash_quantity', :with => amount fill_in 'adjustment_cash_comment', :with => 'Required Comment Text' click_on 'Book' wait_until { page.has_content?('Cash Adjustment successfully created') } end Yes,
8. Given /^a (?:business|current) account$/ do bank = FactoryBoy.create(:bank) the_account_owner = the(:account_owner, name: 'Clark Cuke') account = create_account_for(the_account_owner, location: Country.find_by_name( 'United Kingdom'), currency: 'GBP', bank: bank) create_transactions_for_account( account: account, transaction_types: 'payments') end
9. Oh dear... http://www.flickr.com/photos/8070463@N03/6818380694
10. First thoughts What do we know about code cleanness?
11. Rules of better design Passes all the tests Minimizes duplication Maximizes clarity Has less elements
12. Rules of better design Passes all the tests Minimizes duplication Maximizes clarity Has less elements They
13. Rules of better design Passes all the tests Minimizes duplication Maximizes clarity Has less elements They
14. Rules of better design Passes all the tests Minimizes duplication Maximizes clarity Has less elements They
15. Rules of better design Passes all the tests Minimizes duplication Maximizes clarity Has less elements They
16. Rules of better design Passes all the tests Minimizes duplication Maximizes clarity Has less elements They
17. Maximizing Clarity Pushing the how Thanks
18. Recognizing the relevant @login_as_bank_manager Scenario: Create new business account Given I am on POS Screen And I follow "Add" Then I should see "New Business Account" When I fill in "Code" with "PA11" And I fill in "Name" with "Enrique" And I check "Depository" And I select "GBP" from "RYA" And I fill in "Residence" with "UK" And I press "Create" Then I should see "Business Account - One"
19. Recognizing the relevant @login_as_bank_manager Scenario: Create new business account Given I am on POS Screen And I follow "Add" Then I should see "New Business Account" When I fill in "Code" with "PA11" And I fill in "Name" with "Enrique" And I check "Depository" And I select "GBP" from "RYA" And I fill in "Residence" with "UK" And I press "Create" Then I should see "Business Account - One" Looks
20. Recognizing the relevant @login_as_bank_manager Scenario: Create new business account Given I am on POS Screen And I follow "Add" Then I should see "New Business Account" When I fill in "Code" with "PA11" And I fill in "Name" with "Enrique" And I check "Depository" And I select "GBP" from "RYA" And I fill in "Residence" with "UK" And I press "Create" Then I should see "Business Account - One" Looks
21. Recognizing the relevant @login_as_bank_manager Scenario: Create new business account Given I am on POS Screen And I follow "Add" Then I should see "New Business Account" When I fill in "Code" with "PA11" And I fill in "Name" with "Enrique" And I check "Depository" And I select "GBP" from "RYA" And I fill in "Residence" with "UK" And I press "Create" Then I should see "Business Account - One" Looks
22. What’s the real value Scenario: Creating a new business account Given a bank manager is logged in And he creates a business account with: | code| name | currency| country of residence | | PA11| Enrique | GBP | UK | Then that business account should be available
23. Extracting steps Given(/^a bank manager is logged in$/) do visit ‘/login’ fill_in ‘username’, with: ‘me’ fill_in ‘password’, with: ‘s3cr3t’ click_on ‘Login’ end Then(/^he creates a business account with$/) do |data| # all the creation logic here end Then(/^that business account should be available $/do # and the logic to check that that account is there # here end
24. What if? We could pretend to be someone and act like her? impersonate |ɪmˈpəәːs(əә)neɪt| verb [ with obj. ] pretend to be (another person) for entertainment or fraud: it's a very serious offence to impersonate a police officer. DERIVATIVES impersonator noun ORIGIN early 17th cent. (in the sense ‘personify’): from in-2‘into’ + Latin persona ‘person’, on the pattern of incorporate . http://www.flickr.com/photos/95012874@N00/8274759702
25. The environment #... require_relative 'impersonators' #... class ApplicationWorld include Capybara::DSL # include all other things you want/need include Cucumber::Impersonators end World do ApplicationWorld.new end this
26. The environment #... require_relative 'impersonators' #... class ApplicationWorld include Capybara::DSL # include all other things you want/need include Cucumber::Impersonators end World do ApplicationWorld.new end I
27. Transformations Transform(/^a bank manager$/) do |impersonator| a_bank_manager end
28. Transformations Transform(/^a bank manager$/) do |impersonator| a_bank_manager end This
29. Impersonator module module Cucumber module Impersonators def a_bank_manager @bank_manager ||= BankManager.new self end end end
30. Impersonator module module Cucumber module Impersonators def a_bank_manager @bank_manager ||= BankManager.new self end end end ./features/support/impersonators.rb
31. Impersonator class Given(/^a bank manager is logged in$/) do end visit ‘/login’ fill_in ‘username’, with: ‘me’ fill_in ‘password’, with: ‘s3cr3t’ click_on ‘Login’
32. Impersonator class module Cucumber module Impersonators class BankManager def initialize(world) @world = world end def login @world.visit ‘/login’ @world.fill_in ‘username’, with: ‘me’ @world.fill_in ‘password’, with: ‘s3cr3t’ @world.click_on ‘Login’ end end end end visit ‘/login’ fill_in ‘username’, with: ‘me’ fill_in ‘password’, with: ‘s3cr3t’ click_on ‘Login’ same
33. Wiring it up! Given(/^a bank manager is logged in$/) do visit ‘/login’ fill_in ‘username’, with: ‘me’ fill_in ‘password’, with: ‘s3cr3t’ click_on ‘Login’ end
34. Wiring it up! Given(/^(a bank manager) is logged in$/) do |user| user.login end
35. Or as Matt says...
36. Or as Matt says... Given(/^(a bank manager) is logged in$/), :login, on: user Not
37. What can be impersonated? Your system/app The data layer Anonymous users “I” or the narrator elvis? http://www.flickr.com/photos/27261720@N00/2715725134
38. Example Scenario: Creating a new business account Given a bank manager is logged in And he creates a business account with: | code| name | currency| country of residence | | PA11| Enrique | GBP | UK | Then that business account should be available
39. Example Scenario: Creating a new business account Given a bank manager is logged in And he creates a business account with: | code| name | currency| country of residence | | PA11| Enrique | GBP | UK | Then that business account should be available Where
40. Example Background: Given there is a bank manager in the system Scenario: Creating a new business account Given a bank manager is logged in And he creates a business account with: | code| name | currency| country of residence | | PA11| Enrique | GBP | UK | Then that business account should be available
41. Example Background: Given there is a bank manager in the system Scenario: Creating a new business account Given a bank manager is logged in And he creates a business account with: | code| name | currency| country of residence | | PA11| Enrique | GBP | UK | Then that business account should be available That’s
42. Benefits Impersonators tell a story We know who can do what in one glimpse Clean step definitions You need more?
43. Thank you! Enrique Comba Riepenhausen @ecomba ecomba@patheleven.com Any