Using API spec as an Executable Contract To Mock and Test Microservices

on YouTube ↗24m

" summary

AsyncAPI specifications become executable contracts: Specmatic pulls a spec from Git, spins up a Google Pub/Sub emulator via testcontainers, publishes the example payload to the placeOrder topic, and awaits messages on processOrder and notification topics. Tests are generated dynamically from the spec, validate schemas and enums, catch mismatched keys (e.g. total vs totalAmount), and run locally or in CI. This enables examples-as-payloads driven tests and backward-compatibility testing without handwritten test code.

AI-written summary · about

" chapters (11)

1. 0:00API specs as executable contracts
2. 2:32Problem with handwritten tests
3. 3:37Auto-generate contract tests
4. 5:04Specmatic PubSub testing demo
5. 11:23Request-reply and fan-out patterns
6. 12:51API specs catch breaking changes
7. 16:50AsyncAPI for API design first
8. 19:58Backward compatibility testing
9. 21:42Tests and stubs in CI
10. 22:46Shift-left testing benefits
11. 23:51Summary

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