Getting Started Testing

Concise guide to testing and RSpec basics for new programmers. Gives a good overview of how to test Ruby models with RSpec and steps beginners should take to continue improving their testing skills.

Transcript

1. let(:this_talk) { “Getting Started Testing” } @kylefdoherty
2. New & Experienced Developers
4. the stuff - mental hurdles for beginners - some theory - write some tests - next steps
5. beginners hate testing
6. - I just learned ruby…RSpec WAT? - it’s going to slow me way down - how do I know I’m doing it right?
7. why beginners should test
8. - will help land you a job - good companies write tests - easier to refactor code - more thoughtful about solutions - BETTER CODE
10. a little theory
11. 4 Phase Test 1. setup 2. exercise 3. verify 4. teardown
12. you already test
13. class Product attr_reader :name def initialize(name:) @name = name end def slug name.downcase.gsub(" ", "-") end end #product.rb
14. setup class Product #code end watch = Product.new(name: "Timex Weekender") puts watch.slug #product.rb
15. exercise class Product #code end watch = Product.new(name: "Timex Weekender", price: 30) puts watch.slug #product.rb
16. verify
17. RSpec basics
18. describe block describe Product do end
19. describe block describe Product do describe “#slug" do end end
20. it block describe Product do describe “#slug" do it “slugifies the name" do end end end
21. it block describe Product do describe “#slug" do it “slugifies the name" do # 4 Phases Go Here end end end
22. setup it "slugifies the name" do watch = Product.new(name: "Timex Weekender") end
23. exercise it "slugifies the name" do watch = Product.new(name: "Timex Weekender") slug = watch.slug end
24. verify it "slugifies the name" do watch = Product.new(name: "Timex Weekender") slug = watch.slug expect(slug).to eq("timex-weekender") end
25. a little more theory
26. 1. RED 2. GREEN 3. REFACTOR
27. 1. write a test & watch it fail 2. write code to make the test pass 3. refactor tests & code
28. let’s try it
29. our product class class Product attr_reader :name, :price def initialize(name:, price:) @name = name @price = price end def slug name.downcase.gsub(" ", "-") end end
30. #discount_price - takes the discount % as a parameter (ex: 0.3) - expect it to return the discounted price - has a default discount of 0.2
31. describe "#discount_price" do it "returns the correct discounted price" do end end #product_spec.rb
32. describe "#discount_price" do it "returns the correct discounted price" do watch = Product.new(name: "Timex Weekender", price: 100) end end #product_spec.rb
33. describe "#discount_price" do it "returns the correct discounted price" do watch = Product.new(name: "Timex Weekender", price: 100) discount_price = watch.discount_price(discount: 0.3) end end #product_spec.rb
34. describe "#discount_price" do it "returns the correct discounted price" do watch = Product.new(name: "Timex Weekender", price: 100) discount_price = watch.discount_price(discount: 0.3) expect(discount_price).to eq(70) end end #product_spec.rb
35. rspec product_spec.rb -- color #product_spec.rb
37. def discount_price(discount:) end
39. def discount_price(discount:) price * (1 - discount) end
41. #protip def discount_price(discount:) binding.pry end
42. require './game' describe Product do describe "#slug" do it "slugifies the name" do watch = Product.new(name: "Timex Weekender", price: 100) slug = watch.slug expect(slug).to eq("timex-weekender") end end describe "#discount_price" do it "returns the correct discounted price" do watch = Product.new(name: "Timex Weekender", price: 100) discount_price = watch.discount_price(discount: 0.3) expect(discount_price).to eq(70) end end end # takes the discount % as a parameter (ex: 0.3) # expect it to return the discounted price # has a default discount of 0.2 #product_spec.rb
43. require './game' describe Product do describe "#slug" do it "slugifies the name" do watch = Product.new(name: "Timex Weekender", price: 100) slug = watch.slug expect(slug).to eq("timex-weekender") end end describe "#discount_price" do it "returns the correct discounted price" do watch = Product.new(name: "Timex Weekender", price: 100) discount_price = watch.discount_price(discount: 0.3) expect(discount_price).to eq(70) end end end # takes the discount % as a parameter (ex: 0.3) # expect it to return the discounted price # has a default discount of 0.2 #product_spec.rb
44. require './game' describe Product do describe "#slug" do it "slugifies the name" do watch = Product.new(name: "Timex Weekender", price: 100) slug = watch.slug expect(slug).to eq("timex-weekender") end end describe "#discount_price" do it "returns the correct discounted price" do watch = Product.new(name: "Timex Weekender", price: 100) discount_price = watch.discount_price(discount: 0.3) expect(discount_price).to eq(70) end end end # takes the discount % as a parameter (ex: 0.3) # expect it to return the discounted price # has a default discount of 0.2 #product_spec.rb
45. adding context
46. describe "#discount_price" do context "when no discount is given" do it "returns the price discounted by the default 20%" do end end context "when a discount is given" do it "returns the correct discounted price" do end end end #product_spec.rb
47. describe "#discount_price" do context "when no discount is given" do it "returns the price discounted by the default 20%" do end end context "when a discount is given" do it "returns the correct discounted price" do end end end #product_spec.rb
48. describe "#discount_price" do context "when no discount is given" do it "returns the price discounted by the default 20%" do watch = Product.new(name: "Timex Weekender", price: 100) discount_price = watch.discount_price expect(discount_price).to eq(80) end end context "when a discount is given" do it "returns the correct discounted price" do watch = Product.new(name: "Timex Weekender", price: 100) discount_price = watch.discount_price(discount: 0.3) expect(discount_price).to eq(70) end end end #product_spec.rb
49. describe "#discount_price" do context "when no discount is given" do it "returns the price discounted by the default 20%" do watch = Product.new(name: "Timex Weekender", price: 100) discount_price = watch.discount_price expect(discount_price).to eq(80) end end context "when a discount is given" do it "returns the correct discounted price" do watch = Product.new(name: "Timex Weekender", price: 100) discount_price = watch.discount_price(discount: 0.3) expect(discount_price).to eq(70) end end end #product_spec.rb
50. describe "#discount_price" do context "when no discount is given" do it "returns the price discounted by the default 20%" do watch = Product.new(name: "Timex Weekender", price: 100) discount_price = watch.discount_price expect(discount_price).to eq(80) end end context "when a discount is given" do it "returns the correct discounted price" do watch = Product.new(name: "Timex Weekender", price: 100) discount_price = watch.discount_price(discount: 0.3) expect(discount_price).to eq(70) end end end #product_spec.rb
51. describe "#discount_price" do context "when no discount is given" do it "returns the price discounted by the default 20%" do watch = Product.new(name: "Timex Weekender", price: 100) discount_price = watch.discount_price expect(discount_price).to eq(80) end end context "when a discount is given" do it "returns the correct discounted price" do watch = Product.new(name: "Timex Weekender", price: 100) discount_price = watch.discount_price(discount: 0.3) expect(discount_price).to eq(70) end end end #product_spec.rb
53. def discount_price(discount: 0.2) price * (1 - discount) end
55. refactor
56. describe "#slug" do it "slugifies the name" do watch = Product.new(name: "Timex Weekender", price: 100) slug = watch.slug expect(slug).to eq("timex-weekender") end end describe "#discount_price" do context "when no discount is given" do it "returns the price discounted 20%" do watch = Product.new(name: "Timex Weekender", price: 100) discount_price = watch.discount_price expect(discount_price).to eq(80) end end context "when a discount is given" do it "returns the correct discounted price" do watch = Product.new(name: "Timex Weekender", price: 100) discount_price = watch.discount_price(discount: 0.3) expect(discount_price).to eq(70) end end end #product_spec.rb
57. describe "#slug" do it "slugifies the name" do watch = Product.new(name: "Timex Weekender", price: 100) expect(watch.slug).to eq("timex-weekender") end end describe "#discount_price" do context "when no discount is given" do it "returns the price discounted 20%" do watch = Product.new(name: "Timex Weekender", price: 100) expect(watch.discount_price).to eq(80) end end context "when a discount is given" do it "returns the correct discounted price" do watch = Product.new(name: "Timex Weekender", price: 100) expect(watch.discount_price(discount: 0.3)).to eq(70) end end end #product_spec.rb
58. describe Product do describe "#slug" do it "slugifies the name" do watch = Product.new(name: "Timex Weekender", price: 100) expect(watch.slug).to eq("timex-weekender") end end describe "#discount_price" do context "when no discount is given" do it "returns the price discounted 20%" do watch = Product.new(name: "Timex Weekender", price: 100) expect(watch.discount_price).to eq(80) end end context "when a discount is given" do it "returns the correct discounted price" do watch = Product.new(name: "Timex Weekender", price: 100) expect(watch.discount_price(discount: 0.3)).to eq(70) end end end end #product_spec.rb
59. describe Product do let(:watch) { Product.new(name: "Timex Weekender", price: 100) } describe "#slug" do it "slugifies the name" do expect(watch.slug).to eq("timex-weekender") end end describe "#discount_price" do context "when no discount is given" do it "returns the price discounted 20%" do expect(watch.discount_price).to eq(80) end end context "when a discount is given" do it "returns the correct discounted price" do expect(watch.discount_price(discount: 0.3)).to eq(70) end end end end #product_spec.rb
60. describe Product do let(:watch) { Product.new(name: "Timex Weekender", price: 100) } describe "#slug" do it "slugifies the name" do expect(watch.slug).to eq("timex-weekender") end end describe "#discount_price" do context "when no discount is given" do it "returns the price discounted 20%" do expect(watch.discount_price).to eq(80) end end context "when a discount is given" do it "returns the correct discounted price" do expect(watch.discount_price(discount: 0.3)).to eq(70) end end end end #product_spec.rb
61. tips for success - focus on clarity - you’re telling a story - avoid let and other advanced DSL - DRY tests aren’t always the best tests - spike first - binding.pry
62. next steps - solve 3-5 Project Euler problems - get a copy of Everyday Rails Testing with RSpec - chps 2-4 of Rails 4 in Action
63. recommended resources - Four Phase Test - https://robots.thoughtbot.com/four-phase- test - betterspecs.org (let vs. let! & more) - let vs before, https://www.launchacademy.com/codecabulary/ learn-test-driven-development/rspec/before-vs-let - Everyday Rails Testing with RSpec, https://leanpub.com/ everydayrailsrspec - Rails 4 in Action, http://www.amazon.com/Rails-4-Action- Ryan-Bigg/dp/1617291099
64. @kylefdoherty kyle.doherty@alphasights.com