Testing integrations - The Good, the Bad and the Ugly

Does your Rails app have integrations with third-party APIs? Perhaps your billing system relies on a subscription management tool, or you utilize email marketing applications to engage customers? Enhancing your features through external tools can be powerful, but testing these integrations could pose challenges or be cumbersome. Join me as we explore practical strategies for testing integrations, drawing from real-life experiences at Harvest, where we implemented several integrations – Braintree, Stripe, CustomerIO, Hubspot, Xero, QuickBooks, and more – and gain confidence in safeguarding your codebase during refactorings or API version changes.

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1. Testing Integrations Julia López – Rails World 2024 The Good, the Bad, and the Ugly
2. Julia López From Barcelona ☀ ❤ Rails since 2011 Billing 🤑 & Refactoring 🧹 & Upgrades ⏫ 👾 @yukideluxe
5. What can you expect? 🧐
6. Integrations What do I mean by integrations? ⚙
7. https://www.workato.com/the-connector/software-integration/ “Software integration is the process of connecting one software application with another, typically through their Application Programming Interfaces"
8. External/thirdparty APIs 🗺
9. Testing What kind of testing? ✅
10. https://en.wikipedia.org/wiki/Software_testing “Software testing is the act of checking whether software satis f ies expectations."
11. Automated testing 🤖
12. https://en.wikipedia.org/wiki/Test_automation “Test automation is the use of software separate from the software being tested to control the execution of tests and the comparison of actual outcomes with predicted outcomes”
13. What is the particularity? Why am I focusing on testing external API integrations in this talk?
14. We cannot control thirdparty APIs And there are lots of things we need to worry about… 🚩 🤹
15. Billing Integration Simpli f ied version POST https://api.stripe.com/v1/subscriptions StripeSubscriptionService { "id": "sub_ID", "over_40_more_attributes": "💵" } CREATE
16. class StripeSubscriptionService def self.create(customer:, price:, quantity:) Stripe::Subscription.create( customer: customer, items: [{ price: price, quantity: quantity }], ) rescue Stripe::StripeError => e # handle errors here end end 🤨The Service
17. class StripeSubscriptionService def self.create(customer:, price:, quantity:) Stripe::Subscription.create( customer: customer, items: [{ price: price, quantity: quantity }] ) rescue Stripe::StripeError => e # handle errors here end end The Service
18. class StripeSubscriptionService def self.create(customer:, price:, quantity:) # use your favorite HTTP client here response = post( "https://api.stripe.com/v1/subscriptions", body: { customer: customer, items: [{ price: price, quantity: quantity }] }, headers: { "Authorization" => "Bearer #{ENV["STRIPE_SECRET_KEY"]}" } ) if response.success? JSON.parse(response.body, object_class: OpenStruct) else # handle errors here end end end The Service
19. Different approaches When it comes to test API integrations
20. HIT the API In every test run 👊
21. class StripeSubscriptionServiceTest < ActiveSupport::TestCase test ".create creates a Stripe subscription" do stripe_subscription = StripeSubscriptionService.create( customer: "cus_test_customer_id", price: "price_test_price_id", quantity: 10 ) stripe_subscription_item = stripe_subscription.items.first assert_equal "active", stripe_subscription.status assert_equal "cus_test_customer_id", stripe_subscription.customer assert_equal "price_test_price_id", stripe_subscription_item.price.id assert_equal 10, stripe_subscription_item.quantity end end The Test Hit the API
22. class StripeSubscriptionServiceTest < ActiveSupport::TestCase test ".create creates a Stripe subscription" do stripe_subscription = StripeSubscriptionService.create( customer: "cus_test_customer_id", price: "price_test_price_id", quantity: 10, ) stripe_subscription_item = stripe_subscription.items.first assert_equal "active", stripe_subscription.status assert_equal "cus_test_customer_id", stripe_subscription.customer assert_equal "price_test_price_id", stripe_subscription_item.price.id assert_equal 10, stripe_subscription_item.quantity end end The Test Hit the API
23. class StripeSubscriptionServiceTest < ActiveSupport::TestCase test ".create creates a Stripe subscription" do stripe_subscription = StripeSubscriptionService.create( customer: "cus_test_customer_id", price: "price_test_price_id", quantity: 10 ) stripe_subscription_item = stripe_subscription.items.first assert_equal "active", stripe_subscription.status assert_equal "cus_test_customer_id", stripe_subscription.customer assert_equal "price_test_price_id", stripe_subscription_item.price.id assert_equal 10, stripe_subscription_item.quantity end end The Test Hit the API
24. class StripeSubscriptionServiceTest < ActiveSupport::TestCase test ".create creates a Stripe subscription" do stripe_subscription = StripeSubscriptionService.create( customer: "cus_test_customer_id", price: "price_test_price_id", quantity: 10 ) stripe_subscription_item = stripe_subscription.items.first assert_equal "active", stripe_subscription.status assert_equal "cus_test_customer_id", stripe_subscription.customer assert_equal "price_test_price_id", stripe_subscription_item.price.id assert_equal 10, stripe_subscription_item.quantity end end The Test Hit the API
25. class StripeSubscriptionServiceTest < ActiveSupport::TestCase test ".create creates a Stripe subscription" do stripe_subscription = StripeSubscriptionService.create( customer: "cus_test_customer_id", price: "price_test_price_id", quantity: 10 ) stripe_subscription_item = stripe_subscription.items.first assert_equal "active", stripe_subscription.status assert_equal "cus_test_customer_id", stripe_subscription.customer assert_equal "price_test_price_id", stripe_subscription_item.price.id assert_equal 10, stripe_subscription_item.quantity end end The Test Hit the API
26. The Test Reality
27. bundle exec rails test test/**/billing/**/*_test.rb Run options: --seed 11798 # Running: ................................................................ ................................................................ ................................................................ ................................................................ ................................................................ ................................................................ ................................................................ ................................................................ ................................................................ ............... Finished in 186.088526s, 3.1759 runs/s, 38.0518 assertions/s. 591 runs, 7081 assertions, 0 failures, 0 errors, 0 skips
28. Slow API calls 🐌
29. Benchmark.ms do StripeSubscriptionService.create( customer: "cus_test_customer_id", price: "price_test_price_id", quantity: 10, ) end => 391.109999967739
31. API Rate limits 🙅
32. https://docs.stripe.com/rate-limits
34. Network conditions ⛓💥
36. Fluctuating data 📝
37. class StripeSubscriptionServiceTest < ActiveSupport::TestCase test ".create creates a Stripe subscription" do stripe_subscription = StripeSubscriptionService.create( customer: "cus_test_customer_id", price: "price_test_price_id", quantity: 10 ) stripe_subscription_item = stripe_subscription.items.first assert_equal "active", stripe_subscription.status assert_equal "cus_test_customer_id", stripe_subscription.customer assert_equal "price_test_price_id", stripe_subscription_item.price.id assert_equal 10, stripe_subscription_item.quantity end end The Test Hit the API
38. AuthN & AuthZ 🔐
40. Extra costs 💰
41. 💸
42. CI
43. CI
45. Stubs / Mocks For methods that hit the API
46. The Test Stubs / Mocks class StripeSubscriptionServiceTest < ActiveSupport::TestCase test ".create creates a Stripe subscription" do stripe_subscription = StripeSubscriptionService.create( customer: "cus_test_customer_id", price: "price_test_price_id", quantity: 10 ) stripe_subscription_item = stripe_subscription.items.first assert_equal "active", stripe_subscription.status assert_equal "cus_test_customer_id", stripe_subscription.customer assert_equal "price_test_price_id", stripe_subscription_item.price.id assert_equal 10, stripe_subscription_item.quantity end end
47. class StripeSubscriptionServiceTest < ActiveSupport::TestCase test ".create creates a Stripe subscription" do ✨ YOUR STUBS AND MOCKS GO HERE ✨ stripe_subscription = StripeSubscriptionService.create( customer: "cus_test_customer_id", price: "price_test_price_id", quantity: 10, ) stripe_subscription_item = stripe_subscription.items.first assert_equal "active", stripe_subscription.status assert_equal "cus_test_customer_id", stripe_subscription.customer assert_equal "price_test_price_id", stripe_subscription_item.price.id assert_equal 10, stripe_subscription_item.quantity end end The Test Stubs / Mocks
48. Mocha https://github.com/freerange/mocha ☕ ☕
49. https://github.com/freerange/mocha “A Ruby library for mocking and stubbing.”
51. class StripeSubscriptionService def self.create(customer:, price:, quantity:) Stripe::Subscription.create( customer: customer, items: [{ price: price, quantity: quantity }] ) rescue Stripe::StripeError => e # handle errors here end end The Service
52. stubbed_stripe_subscription = stub( status: "active", customer: "cus_test_customer_id", items: [stub(price: stub(id: "price_test_price_id"), quantity: 10)] ) Stripe::Subscription.expects(:create).with( customer: "cus_test_customer_id", items: [{ price: "price_test_price_id", quantity: 10 }] ).returns(stubbed_stripe_subscription) The Test Stubs / Mocks
53. stubbed_stripe_subscription = stub( status: "active", customer: "cus_test_customer_id", items: [stub(price: stub(id: "price_test_price_id"), quantity: 10)] ) Stripe::Subscription.expects(:create).with( customer: "cus_test_customer_id", items: [{ price: "price_test_price_id", quantity: 10 }] ).returns(stubbed_stripe_subscription) The Test Stubs / Mocks
54. stubbed_stripe_subscription = stub( status: "active", customer: "cus_test_customer_id", items: [stub(price: stub(id: "price_test_price_id"), quantity: 10)] ) Stripe::Subscription.expects(:create).with( customer: "cus_test_customer_id", items: [{ price: "price_test_price_id", quantity: 10 }] ).returns(stubbed_stripe_subscription) The Test Stubs / Mocks
55. stubbed_stripe_subscription = stub( status: "active", customer: "cus_test_customer_id", items: [stub(price: stub(id: "price_test_price_id"), quantity: 10)] ) Stripe::Subscription.expects(:create).with( customer: "cus_test_customer_id", items: [{ price: "price_test_price_id", quantity: 10 }] ).returns(stubbed_stripe_subscription) The Test Stubs / Mocks
56. stubbed_stripe_subscription = stub( status: "active", customer: "cus_test_customer_id", items: [stub(price: stub(id: "price_test_price_id"), quantity: 10)] ) Stripe::Subscription.expects(:create).with( customer: "cus_test_customer_id", items: [{ price: "price_test_price_id", quantity: 10 }] ).returns(stubbed_stripe_subscription) The Test Stubs / Mocks
57. stubbed_stripe_subscription = stub( status: "active", customer: "cus_test_customer_id", items: [stub(price: stub(id: "price_test_price_id"), quantity: 10)] ) Stripe::Subscription.expects(:create).with( customer: "cus_test_customer_id", items: [{ price: "price_test_price_id", quantity: 10 }] ).returns(stubbed_stripe_subscription) The Test Stubs / Mocks
58. class StripeSubscriptionService def self.create(customer:, price:, quantity:) # use your favorite HTTP client here response = post( "https://api.stripe.com/v1/subscriptions", body: { customer: customer, items: [{ price: price, quantity: quantity }] }, headers: { "Authorization" => "Bearer #{ENV["STRIPE_SECRET_KEY"]}" } ) if response.success? JSON.parse(response.body, object_class: OpenStruct) else # handle errors here end end end The Service
59. stub_of_your_http_client_post_response = stub( success?: true, body: { status: "active", customer: "cus_test_customer_id", items: [{ price: { id: "price_test_price_id" }, quantity: 10 }] }.to_json ) YourFavoriteHttpClient.expects(:post).with( "https://api.stripe.com/v1/subscriptions", body: { customer: "cus_test_customer_id", items: [{ price: "price_test_price_id", quantity: 10 }] }, headers: { "Authorization" => "Bearer #{ENV['STRIPE_SECRET_KEY']}" }, ).returns(stub_of_your_http_client_post_response) The Test Stubs / Mocks
60. stub_of_your_http_client_post_response = stub( success?: true, body: { status: "active", customer: "cus_test_customer_id", items: [{ price: { id: "price_test_price_id" }, quantity: 10 }] }.to_json ) YourFavoriteHttpClient.expects(:post).with( "https://api.stripe.com/v1/subscriptions", body: { customer: "cus_test_customer_id", items: [{ price: "price_test_price_id", quantity: 10 }] }, headers: { "Authorization" => "Bearer #{ENV['STRIPE_SECRET_KEY']}" }, ).returns(stub_of_your_http_client_post_response) The Test Stubs / Mocks
61. stub_of_your_http_client_post_response = stub( success?: true, body: { status: "active", customer: "cus_test_customer_id", items: [{ price: { id: "price_test_price_id" }, quantity: 10 }] }.to_json ) YourFavoriteHttpClient.expects(:post).with( "https://api.stripe.com/v1/subscriptions", body: { customer: "cus_test_customer_id", items: [{ price: "price_test_price_id", quantity: 10 }] }, headers: { "Authorization" => "Bearer #{ENV['STRIPE_SECRET_KEY']}" }, ).returns(stub_of_your_http_client_post_response) The Test Stubs / Mocks
62. stub_of_your_http_client_post_response = stub( success?: true, body: { status: "active", customer: "cus_test_customer_id", items: [{ price: { id: "price_test_price_id" }, quantity: 10 }] }.to_json ) YourFavoriteHttpClient.expects(:post).with( "https://api.stripe.com/v1/subscriptions", body: { customer: "cus_test_customer_id", items: [{ price: "price_test_price_id", quantity: 10 }] }, headers: { "Authorization" => "Bearer #{ENV['STRIPE_SECRET_KEY']}" } ).returns(stub_of_your_http_client_post_response) The Test Stubs / Mocks
63. stub_of_your_http_client_post_response = stub( success?: true, body: { status: "active", customer: "cus_test_customer_id", items: [{ price: { id: "price_test_price_id" }, quantity: 10 }] }.to_json ) YourFavoriteHttpClient.expects(:post).with( "https://api.stripe.com/v1/subscriptions", body: { customer: "cus_test_customer_id", items: [{ price: "price_test_price_id", quantity: 10 }], }, headers: { "Authorization" => "Bearer #{ENV['STRIPE_SECRET_KEY']}" } ).returns(stub_of_your_http_client_post_response) The Test Stubs / Mocks
64. stub_of_your_http_client_post_response = stub( success?: true, body: { status: "active", customer: "cus_test_customer_id", items: [{ price: { id: "price_test_price_id" }, quantity: 10 }] }.to_json ) YourFavoriteHttpClient.expects(:post).with( "https://api.stripe.com/v1/subscriptions", body: { customer: "cus_test_customer_id", items: [{ price: "price_test_price_id", quantity: 10 }] }, headers: { "Authorization" => "Bearer #{ENV['STRIPE_SECRET_KEY']}" } ).returns(stub_of_your_http_client_post_response) The Test Stubs / Mocks
65. WebMock https://github.com/bblimke/webmock 😜
66. https://github.com/bblimke/webmock “Library for stubbing and setting expectations on HTTP requests in Ruby."
68. stub_request( :post, "https://api.stripe.com/v1/subscriptions" ).with( headers: { "Authorization" => "Bearer #{ENV["STRIPE_SECRET_KEY"]}" }, body: { customer: "cus_test_customer_id", items: [{ price: "price_test_price_id", quantity: 10 }] } ).to_return( status: 200, body: { status: "active", customer: "cus_test_customer_id", items: [{ price: { id: "price_test_price_id" }, quantity: 10 }] }.to_json ) The Test WebMock
69. stub_request( :post, "https://api.stripe.com/v1/subscriptions" ).with( headers: { "Authorization" => "Bearer #{ENV["STRIPE_SECRET_KEY"]}" }, body: { customer: "cus_test_customer_id", items: [{ price: "price_test_price_id", quantity: 10 }] } ).to_return( status: 200, body: { status: "active", customer: "cus_test_customer_id", items: [{ price: { id: "price_test_price_id" }, quantity: 10 }] }.to_json ) The Test WebMock
70. stub_request( :post, "https://api.stripe.com/v1/subscriptions" ).with( headers: { "Authorization" => "Bearer #{ENV["STRIPE_SECRET_KEY"]}" }, body: { customer: "cus_test_customer_id", items: [{ price: "price_test_price_id", quantity: 10 }] } ).to_return( status: 200, body: { status: "active", customer: "cus_test_customer_id", items: [{ price: { id: "price_test_price_id" }, quantity: 10 }] }.to_json ) The Test WebMock
71. stub_request( :post, "https://api.stripe.com/v1/subscriptions" ).with( headers: { "Authorization" => "Bearer #{ENV["STRIPE_SECRET_KEY"]}" }, body: { customer: "cus_test_customer_id", items: [{ price: "price_test_price_id", quantity: 10 }] } ).to_return( status: 200, body: { status: "active", customer: "cus_test_customer_id", items: [{ price: { id: "price_test_price_id" }, quantity: 10 }] }.to_json ) The Test WebMock
72. stub_request( :post, "https://api.stripe.com/v1/subscriptions" ).with( headers: { "Authorization" => "Bearer #{ENV["STRIPE_SECRET_KEY"]}" }, body: { customer: "cus_test_customer_id", items: [{ price: "price_test_price_id", quantity: 10 }] } ).to_return( status: 200, body: { status: "active", customer: "cus_test_customer_id", items: [{ price: { id: "price_test_price_id" }, quantity: 10 }] }.to_json ) The Test WebMock
73. stubbed_request = stub_request(...) # Run your test here assert_requested stubbed_request The Test WebMock
74. stubbed_request = stub_request(...) # Run your test here assert_requested stubbed_request The Test WebMock
75. # test/test_helper.rb ActiveSupport::TestCase.class_eval do setup do ... WebMock.disable_net_connect! ... end end Con f iguration WebMock
76. ❯ rails test test/services/stripe_subscription_service_test.rb E Error: StripeSubscriptionServiceTest#test_.create_creates_a_Stripe_subscription: WebMock::NetConnectNotAllowedError: Real HTTP connections are disabled. Unregistered request: POST https://api.stripe.com/v1/subscriptions with body ‘customer=cus_test_customer_id&items[0] [price]=price_test_price_id&items[0][quantity]=10' ... You can stub this request with the following snippet: stub_request(:post, "https://api.stripe.com/v1/subscriptions"). with( body: {"customer"=>"cus_test_customer_id", "items"=>[{"price"=>"price_test_price_id", "quantity"=>"10"}]}, headers: { 'Authorization'=>'Bearer OBFUSCATED', }). to_return(status: 200, body: "", headers: {}) ============================================================ app/services/stripe_subscription_service.rb:3:in `create' test/services/stripe_subscription_service_test.rb:5:in `block in <class:StripeSubscriptionServiceTest>' Con f iguration WebMock
77. ❯ rails test test/services/stripe_subscription_service_test.rb E Error: StripeSubscriptionServiceTest#test_.create_creates_a_Stripe_subscription: WebMock::NetConnectNotAllowedError: Real HTTP connections are disabled. Unregistered request: POST https://api.stripe.com/v1/subscriptions with body ‘customer=cus_test_customer_id&items[0] [price]=price_test_price_id&items[0][quantity]=10' ... You can stub this request with the following snippet: stub_request(:post, "https://api.stripe.com/v1/subscriptions"). with( body: {"customer"=>"cus_test_customer_id", "items"=>[{"price"=>"price_test_price_id", "quantity"=>"10"}]}, headers: { 'Authorization'=>'Bearer OBFUSCATED', }). to_return(status: 200, body: "", headers: {}) ============================================================ app/services/stripe_subscription_service.rb:3:in `create' test/services/stripe_subscription_service_test.rb:5:in `block in <class:StripeSubscriptionServiceTest>' Con f iguration WebMock
78. That’s it? We f ixed all the problems? 😍
79. Billing Integration Simpli f ied version POST https://api.stripe.com/v1/subscriptions StripeSubscriptionService { "id": "sub_ID", "over_40_more_attributes": "💵" } CREATE
80. stub_request( :post, "https://api.stripe.com/api/v1/subscriptions" ).with( headers: { "Authorization" => "Bearer #{ENV["STRIPE_SECRET_KEY"]}" }, body: { customer: "cus_test_customer_id", items: [{ price: "price_test_price_id", quantity: 10 }] } ).to_return( status: 200, body: { status: "active", customer: "cus_test_customer_id", items: [{ price: "price_test_price_id", quantity: 10 }] }.to_json ) The Test WebMock
81. https://docs.stripe.com/api/subscriptions/object
82. https://docs.stripe.com/changelog
83. You will need to f ine-tune those stubs & mocks And the responses will vary depending on what you are testing
84. VCR https://github.com/vcr/vcr 📼
85. https://github.com/vcr/vcr “Record your test suite's HTTP interactions and replay them during future test runs for fast, deterministic, accurate tests."
87. class StripeSubscriptionServiceTest < ActiveSupport::TestCase test ".create creates a Stripe subscription" do stripe_subscription = StripeSubscriptionService.create( customer: "cus_test_customer_id", price: "price_test_price_id", quantity: 10, ) stripe_subscription_item = stripe_subscription.items.first assert_equal "active", stripe_subscription.status assert_equal "cus_test_customer_id", stripe_subscription.customer assert_equal "price_test_price_id", stripe_subscription_item.price assert_equal 10, stripe_subscription_item.quantity end end The Test Hit the API
88. class StripeSubscriptionServiceTest < ActiveSupport::TestCase test ".create creates a Stripe subscription" do VCR.use_cassette(“stripe_subscription_service_create”) do stripe_subscription = StripeSubscriptionService.create( customer: "cus_test_customer_id", price: "price_test_price_id", quantity: 10, ) stripe_subscription_item = stripe_subscription.items.first assert_equal "active", stripe_subscription.status assert_equal "cus_test_customer_id", stripe_subscription.customer assert_equal "price_test_price_id", stripe_subscription_item.price assert_equal 10, stripe_subscription_item.quantity end end end The Test VCR
89. The Test VCR
90. "body": { "encoding": "UTF-8", "string": "{\n \"id\": \"sub_PRIVATE\",\n \"object\": \"subscription\",\n \"application\": null,\n \"application_fee_percent\": null,\n \"automatic_tax\": {\n \"enabled\": false,\n \"liability\": null\n },\n \"billing_cycle_anchor\": 1725449818,\n \"billing_cycle_anchor_config\": null,\n \"billing_thresholds\": null,\n \"cancel_at\": null,\n \"cancel_at_period_end\": false,\n \"canceled_at\": null,\n \"cancellation_details\": {\n \"comment\": null,\n \"feedback\": null,\n \"reason\": null\n },\n \"collection_method\": \"charge_automatically\",\n \"created\": 1725449818,\n \"currency\": \"usd\",\n \"current_period_end\": 1756985818,\n \"current_period_start\": 1725449818,\n \"customer\": \"cus_PRIVATE\",\n \"days_until_due\": null,\n \"default_payment_method\": null,\n \"default_source\": null,\n \"default_tax_rates\": [],\n \"description\": null,\n \"discount\": null,\n \"discounts\": [],\n \"ended_at\": null,\n \"invoice_settings\": {\n \"account_tax_ids\": null,\n \"issuer\": {\n \"type\": \"self\"\n }\n },\n \"items\": {\n \"object\": \"list\",\n \"data\": [\n {\n \"id\": \"si_PRIVATE\",\n \"object\": \"subscription_item\",\n \"billing_thresholds\": null,\n \"created\": 1725449818,\n \"discounts\": [],\n \"metadata\": {},\n \"plan\": {\n \"id\": \"price_PRIVATE\",\n \"object\": \"plan\",\n \"active\": true,\n \"aggregate_usage\": null,\n \"amount\": 15828,\n \"amount_decimal\": \"15828\",\n \"billing_scheme\": \"per_unit\",\n \"created\": 1724866294,\n \"currency\": \"usd\",\n \"interval\": \"year\",\n \"interval_count\": 1,\n \"livemode\": false,\n \"metadata\": {},\n \"meter\": null,\n \"nickname\": \”Price NickName\",\n \"product\": \"prod_PRIVATE\",\n \"tiers_mode\": null,\n \"transform_usage\": null,\n \"trial_period_days\": null,\n \"usage_type\": \"licensed\"\n },\n \"price\": {\n \"id\": \"price_PRIVATE\",\n \"object\": \"price\",\n \"active\": true,\n \"billing_scheme\": \"per_unit\",\n \"created\": 1724866294,\n \"currency\": \"usd\",\n \"custom_unit_amount\": null,\n \"livemode\": false,\n \"lookup_key\": \”price_lookup_key\”,\n \"metadata\": {},\n \"nickname\": \”Price Nickname\",\n \"product\": \"prod_PRIVATE\",\n \"recurring\": {\n \"aggregate_usage\": null,\n \"interval\": \"year\",\n \"interval_count\": 1,\n \"meter\": null,\n \"trial_period_days\": null,\n \"usage_type\": \"licensed\"\n },\n \"tax_behavior\": \"exclusive\",\n \"tiers_mode\": null,\n \"transform_quantity\": null,\n \"type\": \"recurring\",\n \"unit_amount\": 15828,\n \"unit_amount_decimal\": \"15828\"\n },\n \"quantity\": 10,\n \"subscription\": \"sub_PRIVATE\",\n \"tax_rates\": []\n }\n ],\n \"has_more\": false,\n \"total_count\": 1,\n \"url\": \"/v1/subscription_items?subscription=sub_PRIVATE\"\n },\n \"latest_invoice\": \"in_PRIVATE\",\n \"livemode\": false,\n \"metadata\": {},\n \"next_pending_invoice_item_invoice\": null,\n \"on_behalf_of\": null,\n \"pause_collection\": null,\n \"payment_settings\": {\n \"payment_method_options\": null,\n \"payment_method_types\": null,\n \"save_default_payment_method\": \"off\"\n },\n \"pending_invoice_item_interval\": null,\n \"pending_setup_intent\": null,\n \"pending_update\": null,\n \"plan\": {\n \"id\": \"price_PRIVATE\",\n \"object\": \"plan\",\n \"active\": true,\n \"aggregate_usage\": null,\n \"amount\": 15828,\n \"amount_decimal\": \"15828\",\n \"billing_scheme\": \"per_unit\",\n \"created\": 1724866294,\n \"currency\": \"usd\",\n \"interval\": \"year\",\n \"interval_count\": 1,\n \"livemode\": false,\n \"metadata\": {},\n \"meter\": null,\n \"nickname\": \”Price nickname\",\n \"product\": \”prod_PRIVATE\",\n \"tiers_mode\": null,\n \"transform_usage\": null,\n \"trial_period_days\": null,\n \"usage_type\": \"licensed\"\n },\n \"quantity\": 10,\n \"schedule\": null,\n \"start_date\": 1725449818,\n \"status\": \"active\",\n \"test_clock\": \"clock_PRIVATE\",\n \"transfer_data\": null,\n \"trial_end\": null,\n \"trial_settings\": {\n \"end_behavior\": {\n \"missing_payment_method\": \"create_invoice\"\n }\n },\n \"trial_start\": null\n}" } The Test VCR
91. class StripeSubscriptionServiceTest < ActiveSupport::TestCase test ".create creates a Stripe subscription" do VCR.use_cassette("stripe_subscription_service_create") do stripe_subscription = StripeSubscriptionService.create( customer: “cus_test_customer_id”, price: "price_test_price_id", quantity: 10, ) stripe_subscription_item = stripe_subscription.items.first assert_equal “active", stripe_subscription.status assert_equal "cus_test_customer_id", stripe_subscription.customer assert_equal "price_test_price_id", stripe_subscription_item.price assert_equal 10, stripe_subscription_item.quantity end end end The Test VCR
92. VCR WebMock Those tools work pretty well together ❤
93. How we test integrations? “Real life” at Harvest
94. # test/test_helper.rb require “vcr” VCR.configure do |c| c.cassette_library_dir = "test/vcr_cassettes" c.hook_into :webmock c.default_cassette_options = { record: ENV["CI"] ? :none : :once, serialize_with: :json, match_requests_on: [:method, :host, :path] } c.allow_http_connections_when_no_cassette = false # default ignored_hosts = [] ignored_hosts << "127.0.0.1" # Capybara c.ignore_hosts *ignored_hosts end Con f iguration VCR
95. # test/test_helper.rb require “vcr" VCR.configure do |c| c.cassette_library_dir = "test/vcr_cassettes" c.hook_into :webmock c.default_cassette_options = { record: ENV["CI"] ? :none : :once, serialize_with: :json, match_requests_on: [:method, :host, :path] } c.allow_http_connections_when_no_cassette = false # default ignored_hosts = [] ignored_hosts << "127.0.0.1" # Capybara c.ignore_hosts *ignored_hosts end Con f iguration VCR
96. # test/test_helper.rb require “vcr" VCR.configure do |c| c.cassette_library_dir = "test/vcr_cassettes" c.hook_into :webmock c.default_cassette_options = { record: ENV["CI"] ? :none : :once, serialize_with: :json, match_requests_on: [:method, :host, :path] } c.allow_http_connections_when_no_cassette = false # default ignored_hosts = [] ignored_hosts << "127.0.0.1" # Capybara c.ignore_hosts *ignored_hosts end Con f iguration VCR
97. # test/test_helper.rb require “vcr" VCR.configure do |c| c.cassette_library_dir = "test/vcr_cassettes" c.hook_into :webmock c.default_cassette_options = { record: ENV["CI"] ? :none : :once, serialize_with: :json, match_requests_on: [:method, :host, :path] } c.allow_http_connections_when_no_cassette = false # default ignored_hosts = [] ignored_hosts << "127.0.0.1" # Capybara c.ignore_hosts *ignored_hosts end Con f iguration VCR
98. # test/test_helper.rb require “vcr" VCR.configure do |c| c.cassette_library_dir = "test/vcr_cassettes" c.hook_into :webmock c.default_cassette_options = { record: ENV["CI"] ? :none : :once, serialize_with: :json, match_requests_on: [:method, :host, :path] } c.allow_http_connections_when_no_cassette = false # default ignored_hosts = [] ignored_hosts << "127.0.0.1" # Capybara c.ignore_hosts *ignored_hosts end Con f iguration VCR
99. # test/test_helper.rb require “vcr” VCR.configure do |c| c.cassette_library_dir = "test/vcr_cassettes" c.hook_into :webmock c.default_cassette_options = { record: ENV["CI"] ? :none : :once, serialize_with: :json, match_requests_on: [:method, :host, :path] } c.allow_http_connections_when_no_cassette = false # default ignored_hosts = [] ignored_hosts << "127.0.0.1" # Capybara c.ignore_hosts *ignored_hosts end Con f iguration VCR
100. # test/test_helper.rb require “vcr" VCR.configure do |c| c.cassette_library_dir = "test/vcr_cassettes" c.hook_into :webmock c.default_cassette_options = { record: ENV["CI"] ? :none : :once, serialize_with: :json, match_requests_on: [:method, :host, :path] } c.allow_http_connections_when_no_cassette = false # default ignored_hosts = [] ignored_hosts << "127.0.0.1" # Capybara c.ignore_hosts *ignored_hosts end Con f iguration VCR
101. # test/test_helper.rb require “vcr" VCR.configure do |c| c.cassette_library_dir = "test/vcr_cassettes" c.hook_into :webmock c.default_cassette_options = { record: ENV["CI"] ? :none : :once, serialize_with: :json, match_requests_on: [:method, :host, :path] } c.allow_http_connections_when_no_cassette = false # default ignored_hosts = [] ignored_hosts << "127.0.0.1" # Capybara c.ignore_hosts *ignored_hosts end Con f iguration VCR
102. # test/test_helper.rb ActiveSupport::TestCase.class_eval do setup do ... WebMock.disable_net_connect! ... end end Con f iguration WebMock
103. Con f iguration ❯ rails test test/services/stripe_subscription_service_test.rb E Error: StripeSubscriptionServiceTest#test_.create_creates_a_Stripe_subscription: RuntimeError: Neutered Exception VCR::Errors::UnhandledHTTPRequestError: ================================================================================ An HTTP request has been made that VCR does not know how to handle: POST https://api.stripe.com/v1/subscriptions There is currently no cassette in use. There are a few ways you can configure VCR to handle this request: * If you're surprised VCR is raising this error and want insight about how VCR attempted to handle the request, you can use the debug_logger configuration option to log more details [1]. * If you want VCR to record this request and play it back during future test runs, you should wrap your test (or this portion of your test) in a `VCR.use_cassette` block [2]. * If you only want VCR to handle requests made while a cassette is in use, configure `allow_http_connections_when_no_cassette = true`. VCR will ignore this request since it is made when there is no cassette [3]. * If you want VCR to ignore this request (and others like it), you can set an `ignore_request` callback [4]. [1] https://benoittgt.github.io/vcr/?v=6-3-1#/configuration/debug_logging [2] https://benoittgt.github.io/vcr/?v=6-3-1#/getting_started [3] https://benoittgt.github.io/vcr/?v=6-3-1#/configuration/allow_http_connections_when_no_cassette [4] https://benoittgt.github.io/vcr/?v=6-3-1#/configuration/ignore_request ================================================================================ app/services/stripe_subscription_service.rb:3:in `create' test/services/stripe_subscription_service_test.rb:6:in `block in <class:StripeSubscriptionServiceTest>' VCR
104. Con f iguration ❯ rails test test/services/stripe_subscription_service_test.rb E Error: StripeSubscriptionServiceTest#test_.create_creates_a_Stripe_subscription: RuntimeError: Neutered Exception VCR::Errors::UnhandledHTTPRequestError: ================================================================================ An HTTP request has been made that VCR does not know how to handle: POST https://api.stripe.com/v1/subscriptions There is currently no cassette in use. There are a few ways you can configure VCR to handle this request: * If you're surprised VCR is raising this error and want insight about how VCR attempted to handle the request, you can use the debug_logger configuration option to log more details [1]. * If you want VCR to record this request and play it back during future test runs, you should wrap your test (or this portion of your test) in a `VCR.use_cassette` block [2]. * If you only want VCR to handle requests made while a cassette is in use, configure `allow_http_connections_when_no_cassette = true`. VCR will ignore this request since it is made when there is no cassette [3]. * If you want VCR to ignore this request (and others like it), you can set an `ignore_request` callback [4]. [1] https://benoittgt.github.io/vcr/?v=6-3-1#/configuration/debug_logging [2] https://benoittgt.github.io/vcr/?v=6-3-1#/getting_started [3] https://benoittgt.github.io/vcr/?v=6-3-1#/configuration/allow_http_connections_when_no_cassette [4] https://benoittgt.github.io/vcr/?v=6-3-1#/configuration/ignore_request ================================================================================ app/services/stripe_subscription_service.rb:3:in `create' test/services/stripe_subscription_service_test.rb:6:in `block in <class:StripeSubscriptionServiceTest>' VCR
105. # test/test_helper.rb require “vcr" VCR.configure do |c| c.cassette_library_dir = "test/vcr_cassettes" c.hook_into :webmock c.default_cassette_options = { record: ENV["CI"] ? :none : :once, serialize_with: :json, match_requests_on: [:method, :host, :path], } c.allow_http_connections_when_no_cassette = false # default ignored_hosts = [] ignored_hosts << "127.0.0.1" # Capybara c.ignore_hosts *ignored_hosts end Con f iguration VCR
106. Extra tooling # test/support/vcr.rb ActiveSupport::TestCase.class_eval do setup do if ENV["VCR_REFRESH"] == "true" Dir["#{VCR.configuration.cassette_library_dir}/#{vcr_filename}.json"].each do |file| puts "VCR: deleting recorded cassette: #{file}" FileUtils.rm_f(file) end end end def use_test_named_cassette(vcr_options = {}) VCR.use_cassette(vcr_filename, vcr_options) do |cassette| yield cassette end end def vcr_filename test_name_match = name.match(/(test_)(.+)/) test_description = test_name_match[2] filename = "#{vcr_prefix}#{test_description}".gsub(/[^\w-]+/, "_") # Avoids hitting the filesystem's maximum filename if filename.length > 248 # 255 - 1 (_) - 6 (MD5 hash length) filename = filename[0..247] end
107. Extra tooling # test/support/vcr.rb ActiveSupport::TestCase.class_eval do setup do if ENV["VCR_REFRESH"] == "true" Dir["#{VCR.configuration.cassette_library_dir}/#{vcr_filename}.json"].each do |file| puts "VCR: deleting recorded cassette: #{file}" FileUtils.rm_f(file) end end end def use_test_named_cassette(vcr_options = {}) VCR.use_cassette(vcr_filename, vcr_options) do |cassette| yield cassette end end def vcr_filename test_name_match = name.match(/(test_)(.+)/) test_description = test_name_match[2] filename = "#{vcr_prefix}#{test_description}".gsub(/[^\w-]+/, "_") # Avoids hitting the filesystem's maximum filename if filename.length > 248 # 255 - 1 (_) - 6 (MD5 hash length) filename = filename[0..247] end
108. end def use_test_named_cassette(vcr_options = {}) VCR.use_cassette(vcr_filename, vcr_options) do |cassette| yield cassette end end def vcr_filename test_name_match = name.match(/(test_)(.+)/) test_description = test_name_match[2] filename = "#{vcr_prefix}#{test_description}".gsub(/[^\w-]+/, "_") # Avoids hitting the filesystem's maximum filename if filename.length > 248 # 255 - 1 (_) - 6 (MD5 hash length) filename = filename[0..247] end "#{filename}_#{Digest::MD5.hexdigest(test_description)[0..5]}" end def vcr_prefix prefix_match = self.class.name.match(/(.+)Test/) prefix = prefix_match[1].underscore.gsub("/", "__") "#{prefix}__" end def vcr_recorded_at VCR.current_cassette&.originally_recorded_at || Time.now Extra tooling
109. Show me the tests! 🙌
110. We use all approaches For real
111. Hit the API On our local setup # db/seeds.rb require “webmock" WebMock.enable! WebMock.disable_net_connect!(allow: “api.stripe.com") require_relative "seeds/stripe_billing"
112. Hit the API On our system tests # test/system/billing/upgrade_test.rb test "trial to paid" do with_stripe_customer(company: @company) do |subscription| visit company_account_path click_on "Upgrade plan" fill_in_credit_card_details fill_in_billing_address ... assert_text "Harvest Monthly with 1 seat" ... click_on "Upgrade" assert_text "Thanks for signing up!" subscription.reload assert_equal "active", subscription.status assert subscription.credit_card end end
113. Hit the API On our system tests # test/system/billing/upgrade_test.rb test "trial to paid" do with_stripe_customer(company: @company) do |subscription| visit company_account_path click_on "Upgrade plan" fill_in_credit_card_details fill_in_billing_address ... assert_text "Harvest Monthly with 1 seat" ... click_on "Upgrade" assert_text "Thanks for signing up!" subscription.reload assert_equal "active", subscription.status assert subscription.credit_card end end
114. Puf f ingBilly https://github.com/oesmith/pu ff ing-billy 🚂
115. https://github.com/oesmith/pu ff ing-billy “A rewriting web proxy for testing interactions between your browser and external sites. Works with ruby + rspec."
117. # test/controllers/sign_ups_controller_test.rb test "GET /xero_sign_up if error" do XeroRuby::ApiClient .any_instance .stubs(:get_token_set_from_callback) .raises(XeroRuby::ApiError.new(code: 400)) get xero_sign_up_path assert_response :not_found end Stubs / Mocks External gems
118. # test/controllers/sign_ups_controller_test.rb test "GET /xero_sign_up if error" do XeroRuby::ApiClient .any_instance .stubs(:get_token_set_from_callback) .raises(XeroRuby::ApiError.new(code: 400)) get xero_sign_up_path assert_response :not_found end Stubs / Mocks External gems
119. # test/services/zendesk/wrapper_test.rb def stub_faraday_connection conn = Faraday.new do |builder| stubs = Faraday::Adapter::Test::Stubs.new yield stubs builder.adapter :test, stubs end Faraday.expects(:new).at_least_once.returns(conn) end Stubs / Mocks Http client
120. # test/services/zendesk/wrapper_test.rb def stub_faraday_connection conn = Faraday.new do |builder| stubs = Faraday::Adapter::Test::Stubs.new yield stubs builder.adapter :test, stubs end Faraday.expects(:new).at_least_once.returns(conn) end Stubs / Mocks Http client
121. Stubs / Mocks WebMock # test/lib/forecast/account_test.rb test ".find returns Forecast::Account if account exists in Forecast" do forecast_account_request = stub_request(:get, forecast_account_url).to_return(forecast_account_response) forecast_account = Forecast::Account.find(1) assert_equal 1, forecast_account.id assert_equal "Harvest", forecast_account.name assert_requested forecast_account_request end
122. Stubs / Mocks WebMock # test/lib/forecast/account_test.rb test ".find returns Forecast::Account if account exists in Forecast" do forecast_account_request = stub_request(:get, forecast_account_url).to_return(forecast_account_response) forecast_account = Forecast::Account.find(1) assert_equal 1, forecast_account.id assert_equal "Harvest", forecast_account.name assert_requested forecast_account_request end
123. Stubs / Mocks VCR # test/models/billing/taxjar_test.rb test "#create_order" do use_test_named_cassette do vcr_recorded_date = vcr_recorded_at.to_date transaction_id = vcr_recorded_at.to_i.to_s response = Taxjar.create_order( transaction_id: transaction_id, transaction_date: vcr_recorded_date, ... ) assert_equal transaction_id, response["order"]["transaction_id"] assert_equal vcr_recorded_date.to_s, response["order"]["transaction_date"] end end
124. Stubs / Mocks VCR # test/models/billing/taxjar_test.rb test "#create_order" do use_test_named_cassette do vcr_recorded_date = vcr_recorded_at.to_date transaction_id = vcr_recorded_at.to_i.to_s response = Taxjar.create_order( transaction_id: transaction_id, transaction_date: vcr_recorded_date, ... ) assert_equal transaction_id, response["order"]["transaction_id"] assert_equal vcr_recorded_date.to_s, response["order"]["transaction_date"] end end
125. Do we have all the problems?
126. Network conditions Retries set up in CI
127. # lib/tasks/test/xero.rake namespace :test do namespace :xero do desc "Connects to Xero via OAuth v2 and writes to … keys that are usable for 30 minutes" task authorize: :environment do ... end end end AuthN & AuthZ Extra tooling
128. # test/support/stripe_billing_test_helper.rb module StripeBillingTestHelper def with_stripe_customer(...) end def with_stripe_active_subscription(...) end end Fluctuating data Extra tooling
129. # test/billing/coupon_test.rb test ".current_coupons returns list of available coupons" do use_test_named_cassette do current_coupons = Coupon.current_coupons assert current_coupons.count > 0 end end Fluctuating data Soft assertions
130. # test/billing/coupon_test.rb test ".current_coupons returns list of available coupons" do use_test_named_cassette do current_coupons = Coupon.current_coupons assert current_coupons.count > 0 end end Fluctuating data Soft assertions
132. ✨ VCR ✨
133. The “Ugly” 👹
136. The Bad 😈
137. Extra tooling 🛠
138. Extra documentation 📝
139. Not always failproof 😅
140. The Good 😇
141. Full visibility on HTTP requests & responses 🕵
142. Know whether you are doing extra API requests 🔁
143. Not manually created stubs 💾
144. Makes easier upgrading, extending functionality and refactoring 🤩
146. Better test suite 🤞 😌
147. THANK YOU 🥰 Any questions? Code review? Find me around