Testing microservices the right way

Microservices shine in many aspects, but testability. Whenever you deploy a service, no matter how small it is, as long as it has dependencies, you have to keep them in mind. In Toptal, we realized the complexity of the integration testing when started our path from a monolithic application to microservices. In this talk, I’ll show what criteria we used to make a smart decision, what tools we haven’t chosen and how contract testing simplified our development flow and CI.

Transcript

1. Testing microservices
   the right way
   Tatiana Shepeleva @ Toptal
   

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2. Tatiana Shepeleva @ Toptal
   

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3. • I am Quality Assurance Engineer
   • Love my job
   • 36 countries
   

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4. toptal.com
   

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5. Testing microservices
   the right way
   

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6. Microservices are great
   

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7. Microservices are light
   

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8. Microservices are isolated
   

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9. Microservices are fun
   

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10. Microservices are fun
    

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12. ~2000 end-to-end* tests
    * also known as acceptance, UI or business tests
    

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13. ~3800 min
    

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17. Complications
    • Have different databases
    • Use different languages
    • Work with different protocols
    

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18. +5 min/service
    

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19. What’s wrong with end-to-end tests?
    • Expensive and complex infrastructure
    • Time consuming
    • Flaky
    

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22. Test integration separately
    

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23. Requirements
    •Ruby
    •JavaScript
    •Scala/JVM
    •Elixir
    •WebSocket support
    •Easy to update tests
    •Provider can’t break consumers
    

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24. Record & Replay
    

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27. Record & Replay
    Polly.JS VCR
    Ruby ❌ ✅
    JavaScript ✅ ✅
    Scala/JVM ❌ ✅
    Elixir ❌ ✅
    WebSocket support ✅ ❌
    Easy to update tests ❌ ❌
    Provider can’t break consumers ❌ ❌
    

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28. Fake server
    

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30. Fake servers
    Wiremock Mockserver
    Ruby ✅ ✅
    JavaScript ✅ ✅
    Scala/JVM ✅ ✅
    Elixir ❌
    WebSocket support ❌ ❌
    Easy to update tests ✅ ✅
    Provider can’t break consumers ❌ ❌
    

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31. Contract tests
    

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35. Contract tests
    Spring Cloud Pact
    Ruby ❌ ✅
    JavaScript ❌ ✅
    Scala/JVM ✅ ✅
    Elixir ❌
    Web Socket support
    Easy to update tests ✅ ✅
    Provider can’t break consumers ✅ ✅
    

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36. Cons
    • Expensive and complex infrastructure ✅
    • Time consuming ✅
    • Flaky ✅
    

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37. Cons
    • Not a functional testing
    

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38. docs.pact.io
    

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39. Pact
    • Support different languages (Ruby, JS, Go,
    PHP, Python, JVM)
    • Framework-agnostic
    • Language-agnostic contract (JSON)
    

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47. GraphQL?
    

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52. WebSockets?
    

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53. Experimental support
    Pact-JS
    

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54. gRPC?
    

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55. No
    but may be - #protobufs
    

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56. Storage for contracts
    • Your CI
    • Your codebase
    • Pact Broker
    

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57. Pact Broker
    • Stores versions and tags
    • Webhooks to trigger checks or notifications
    • can-i-deploy tool
    

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62. Pact Broker
    PactFlow
    

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65. How is it actually going to work?
    

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66. Consumer flow
    

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67. Consumer flow
    

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68. Consumer flow
    

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69. Consumer flow
    

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70. Consumer flow
    

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71. Consumer flow
    

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72. Consumer flow
    

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73. Consumer flow
    

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74. Consumer flow
    

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75. Provider flow
    

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76. Provider flow
    

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77. Provider flow
    

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78. Provider flow
    

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79. Provider flow
    

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80. Provider flow
    

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81. The Right Way
    • 10 instead of 3800 min
    • Contract tests are a part of unit tests
    • Number of end-to-end tests minimal
    

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82. The end
    Tatiana Shepeleva
    tati.engineer
    

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