Testing Serverless Applications - TestBusters-Night Vienna

Transcript

1. Testing Serverless Applications
2. Meet Alex
3. Try serverless! AWS Lambda!
4. Try serverless! AWS Lambda!
10. But how do they fit serverless in their common development process?
14. Meet Slobodan
15. Slobodan Stojanovic CTO @ Cloud Horizon and VacationTracker.io co-author of Serverless Applications with Node.js book AWS Serverless Hero @slobodan_ effortless-serverless.com
16. Local testing
17. Can you run serverless apps locally?
18. • Azure Functions Core Tools (for Azure functions) • AWS SAM CLI (for AWS SAM) • third-party tools (ie. localstack) • docker-lambda for AWS Lambda local simulation • run Node.js function locally • and more…
19. How can you run a Node.js function locally?
20. How do you run any Node.js function locally?
21. const
23. But what about permissions or other services, such as AWS Cognito or Kinesis?
24. You can run parts of your code locally to speed up the development, but not everything
25. But, even multiple environments per developer are still cheap and (relatively) easy to setup
26. Can we do better?
27. Yes, write tests!
29. Automated testing
30. Why do we need to test serverless application?
31. Tools for testing
32. You can use tools that you are already using
33. • Jasmine • Mocha • Jest • any other popular tool For example, for Node.js you can use:
34. What should you test in a serverless app?
35. Testing pyramid
37. Testing pyramid vs "Serverless testing pyramid"
39. Integration tests are cheaper, but also more important, because common serverless app is split into many small pieces
40. How to write testable function?
41. • configuration risks • technical workflow risks • business logic risks • integration risks
42. Hexagonal architecture!
43. Allow an application to equally be driven by users, programs, automated test or batch scripts, and to be developed and tested in isolation from its eventual run-time devices and databases. Alistair Cockburn
46. Unit testing
47. Unit testing is the same as for any other app
48. • small units • fully covered with tests • "mock" adapters
49. Integration testing
50. Integration tests important than ever
51. • hexagonal architecture • be smart • test integrations that you own • or test your code with a different adapter
52. How does this look in practice?
54. UI testing
55. Serverless is mainly a back end thing, why do we mention UI tests?
56. UI tests are slow and expensive
57. Benefits of serverless are cheap infrastructure and easy/fast parallelization
59. • puppeteer • appraise.qa • and others…
61. CI / CD
62. It works the same way as any other app
63. Use your favorite deployment tool from CI to deploy your serverless app
64. Popular CI/CD tools
65. • Jenkins • Travis CI • Semaphore CI • AWS CodeBuild • and many more
66. We automated deployment from git branches to different stages (ie. production, dev, staging, qa)
68. (QA) Manual testing
69. Stages and deployments are cheap and often fast to setup
70. You don't pay for your app infrastructure if no-one is using it
71. Having test environments was never cheaper
72. Bonus: You can promote tested function to production, so QA tests the same function that will be in production
74. And they lived happily ever after…
78. Risks and challenges
79. Deployment risk
80. Units are smaller and easier to test, but deployment, triggers and permissions are not trivial (but they are getting easier and easier)
81. You should use well tested and mature deployment tool
82. Popular deployment tools
83. • Serverless Framework • Claudia.js • AWS SAM • .architect • and many more
84. Integration errors and changes
85. Your app might just work*, but integrations can change and cause failures
86. How do you make sure they don't?
87. You can't. But you should do monitoring and error tracking!
88. Monitoring/error-tracking tools
89. • Built-in tools (CloudWatch, X-Ray for AWS) • Epsagon • IOpipe • Dashbird • Thundra • and others
90. Serverless apps often heavily relies on front end, in those cases you need to track front end errors as well
91. desole.io
96. Summary
97. • you can run/test some parts of serverless app locally • automated tests are important, but be smart • use hexagonal architecture to stay flexible • use CI/CD for tests and deployment to different stages • QA can test the same function you are deploying to production • use mature and tested deployment tools, and track and analyze errors
98. A few things that I mentioned in the talk: claudiajs.com desole.io vacationtracker.io
99. @slobodan_ Slides: bit.ly/serverless-testing-slides If you prefer article version: bit.ly/serverless-testing-article
100. One more thing…
101. @slobodan_ First footage of @slobodan_ and @simalexan as AWS Serverless Heroes Private archive
102. Serverless Applications with Node.js Use claudia40 promo code for 40% off serverless-book.com @slobodan_
103. Thank you!
104. Thank you! Danke!