Creating and evolving contracts with Clojure.spec @ Helpshift

I talk about how we used Clojure.spec @ Helpshift to create and evolve contracts between Frontend apps and Backend servers.

Transcript

1. CREATING AND EVOLVING CONTRACTS WITH CLOJURE.SPEC A new way to do develop with Client app teams @KapilReddy Principal Engineer
2. CLOJURE.SPEC
8. PROBLEM
9. CURRENT DEV CYCLE • Product requirements document
10. CURRENT DEV CYCLE • Product requirements document • Backend Engineer + Frontend Engineer write contracts
11. CURRENT DEV CYCLE • Product requirements document • Backend Engineer + Frontend Engineer write contracts • Backend Engineer + Frontend Engineer start work in parallel
12. CURRENT DEV CYCLE • Product requirements document • Backend Engineer + Frontend Engineer write contracts • Backend Engineer + Frontend Engineer start work in parallel • Integrate and test contracts/flows when both pieces are ready
13. PAIN POINTS • Verification of contracts not automated
14. PAIN POINTS • Verification of contracts not automated • Client app team is blocked by backend team to verify if things are working
15. PAIN POINTS • Verification of contracts not automated • Client app team is blocked by backend team to verify if things are working • Integration is late in dev process
17. PAIN POINTS • Verification of contracts not automated • Client app team is blocked by backend team to verify if things are working • Integration is late in dev process • Contract documentation can diverge not always up- to-date
19. CAN WE DO BETTER?
20. HOW/WHERE TO CONTRACT?
21. HOW/WHERE TO CONTRACT? • Contracts with clients - JS + Android + iOS
22. HOW/WHERE TO CONTRACT? • Contracts with clients - JS + Android + iOS • All clients talk to Clojure code
23. HOW/WHERE TO CONTRACT? • Contracts with clients - JS + Android + iOS • All clients talk to Clojure code • Clojure.spec to the rescue!
24. STAGE -1 WRITE CONTRACTS
25. SPEC FOR A ROUTE
26. SPEC FOR A ROUTE
27. ROUTE WITH METADATA
28. MOCKED RESPONSE
29. STAGE - 2 IMPLEMENTATION
30. VIEW FROM CLIENT CODE INCORRECT REQUEST
31. VIEW FROM CLOJURE CODE
32. VIEW FROM CLOJURE CODE
33. AUTOMATE - DOC GENERATION Add error reports for broken responses
34. WHAT ABOUT POST?
35. MOCKING POST REQUEST • Writes need to be persisted for certain UI flows to be testable
36. MOCKING POST REQUEST • Writes need to be persisted for certain UI flows to be testable • Atom to the rescue!
37. MOCKING POST REQUEST • Writes need to be persisted for certain UI flows to be testable • Atom to the rescue! • Mocking CRUD operation is straightforward
38. MOCKING POST REQUEST • Writes need to be persisted for certain UI flows to be testable • Atom to the rescue! • Mocking CRUD operation is straightforward • Gotcha! - It can become a rabbit hole
39. PAIN POINTS • Verification of contracts not automated • Client app team is blocked by backend team to verify if things are working • Integration is late in dev process • Contract documentation can diverge not always up- to-date
40. PAIN POINTS • Verification of contracts not automated • Client app team is blocked by backend team to verify if things are working • Integration is late in dev process • Contract documentation can diverge not always up- to-date
41. PAIN POINTS • Verification of contracts not automated • Client app team is blocked by backend team to verify if things are working • Integration is late in dev process • Contract documentation can diverge not always up- to-date
42. PAIN POINTS • Verification of contracts not automated • Client app team is blocked by backend team to verify if things are working • Integration is late in dev process • Contract documentation can diverge not always up- to-date
43. PAIN POINTS • Verification of contracts not automated • Client app team is blocked by backend team to verify if things are working • Integration is late in dev process • Contract documentation can diverge not always up- to-date
44. NEW DEV CYCLE • Product requirements document • Backend Engineers write contracts in Clojure + Spec with help from Frontend engineers • Both start work in parallel • Both checkpoint and verify against Spec • Integrate and test flows when both pieces are ready
45. SUGGESTIONS? QUESTIONS? WE ARE HIRING! https://jobs.lever.co/helpshift @KapilReddy