1. Testing
Strategies for
Micro-services
Architecture
Ketan Soni
Jesal Mistry
June 2014

2. 2
What is a micro-service?

3. 3
Example
I want to purchase a product
from an e-commerce website

4. 4
Monolithi
c system
MasterCard / VisaLogistics
Cart Catalog
Authentication
Payment
Fulfilment
E-commerce
website

5. 5
Unix philosophy:
Write programs that do one thing and
do it well.

6. 6
Micro-
Services
system
MasterCard / VisaLogistics
Cart
Service
Payment
Service
Authentication
Service
Fulfilment
Service
Catalog
Service
E-commerce
website

7. 7
Challenges
in testing Distributed system complexity
• Inter service communication
• Asynchronous nature
• Dependency management
Challenges
in testing

8. 8
Testing
Strategies
Top-down
Big Bang
Hybrid / Context Driven
Bottom-up

9. 9
Our
Approach
Bottom-up testing
• Test the domain
• Tests closer to the code
• Integrate Early
• Use Mocks / Stubs
• Focus is on Test Pyramid
• Helps visualize/categorize test
coverage better

10. 10
Test
Pyramid
Unit
Contract
E2E Integration
UI
Consumer
Driven Contract
Manual /
Exploratory
Bottom-up testing

11. 11
Test
Pyramid
Unit
Contract
E2E Integration
UI
Consumer
Driven Contract
Manual /
Exploratory

12. 12
Unit Test
Layer
• Test the domain
• Should focus on the code under test
• Maximum test coverage

13. 13
Unit Test
Layer
Authentication
Service
Payment Service
Catalog Service
Unit tests
- addItem
- removeItem
- verifyCreditCard
Cart Service
Fulfilment
Service

14. 14
Test
Pyramid
Unit
Contract
E2E Integration
UI
Consumer
Driven Contract
Manual /
Exploratory

15. 15
Contract
Test Layer • Test one end-point at a time
• Treat the service as a black box
• These tests are end to end within the bounds of
the service
• Assertion are on response e.g. JSON body
• Stub out the dependencies
Contract
Test Layer

16. 16
Contract
Test Layer
Contract
Test Layer
Contract tests
POST /cart/{:product_id}
HTTP Request
HTTP
Response
JSON …....
Cart Service
Mock
Authentication
Service
Mock
Catalog
Service
Mock
Fulfilment
Service
Mock
Payment
Service

17. 17
Unit
Contract
E2E Integration
UI
Consumer
Driven Contract
Manual /
Exploratory
Test
Pyramid

18. 18
End to End
Integration
Test layer
• Test End to End user journey to make sure that
the business flow works as expected
• These covers interaction of all the available
services
End to End
Integration
Test Layer

19. 19
End to End
Integration
Test layer E2E Integration tests
Cart Service
Place an order
Payment Service
Authentication
Service
Catalog Service
Fulfilment
Service
Verify that the order is placed Mock
Logistics
Mock
Mastercard
End to End
Integration
Test Layer

20. 20
Test
Pyramid
Unit
Contract
E2E Integration
UI
Consumer
Driven Contract
Manual /
Exploratory

21. 21
Consumer
Driven
Contract
Test layer • In case of third-party system, we had tests to
make sure that external systems behave the
way we expect them to.
Consumer
Driven
Contract
Test Layer

22. 22
Consumer
Driven
Contract
Test layer
Consumer Driven
Contract tests
MasterCard / Visa
Service
Consumer
Driven
Contract
Test Layer
Verify Credit Card
HTTP Request
HTTP
Response
Success

23. 23
Test
Pyramid
Unit
Contract
E2E Integration
UI
Consumer
Driven Contract
Manual /
Exploratory

24. 24
UI Test
Layer
• For the UI layer, we wrote tests for the End to
End user journey which also covered the
external 3rd party interactions
• UI tests were minimal

25. 25
UI Test
Layer
User Interface Journey tests
Authentication
Service
Fulfilment Service
Payment Service
Cart Service
As a user
I should be able
to purchase
a mobile from
a website
UI
MasterCard / Visa Logistics

26. 26
Test
Pyramid
Unit
Contract
E2E Integration
UI
Consumer
Driven Contract
Manual /
Exploratory

27. 27
References
• Logging
• Inter - Service effects
• Gracefully handle errors
• Look & Feel
Manual /
Exploratory

28. 28
References
• http://en.wikipedia.org/wiki/Unix
• http://davidmorgantini.blogspot.co.uk/2014/03/microservices-
effective-testing.html
• http://martinfowler.com/articles/microservices.html
• https://github.com/tobyclemson
References

29. 29
Questions
?