Contract Testing in Python for a Data Science API
summary
Demo of using JSON Schema as a formal contract for a Python-backed REST microservice, showing concrete tests that validate request and response shape rather than brittle exact values. Shows tooling: generating schemas with quicktype, validating with jsonschema.validate in pytest, enumerating all validation errors to produce precise 4xx messages, and deploying a Flask service on Cloud Foundry. Promises examples, sample code, and CI-friendly patterns for swapping implementations and A/B testing.
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chapters (17)
- 0:00Introduction
- 1:46API collaboration challenge
- 3:49RESTful API design
- 5:40API contracts matter
- 8:27Self-describing data formats
- 9:54Need for contract testing
- 12:23JSON Schema solution
- 13:05JSON Schema basics
- 16:17Generating JSON Schema
- 18:26JSON Schema validation
- 19:52Contract testing benefits
- 21:59Error messages with JSON Schema
- 22:41Recap
- 24:26Separation of concerns
- 25:55JSON Schema advantages
- 27:21Swagger integration
- 28:05Cloud Foundry deployment
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