Vincent Hennig & Anupam Krishnamurthy

Contract Testing - How do you tame an external API that constantly breaks your tests

A partner API update paralyzed our pipeline for 172 hours. Here's the contract testing strategy that cut our recovery time to just four.

Contract Testing - How do you tame an external API that constantly breaks your tests
#1about 4 minutes

How a fragile external API broke our tests

A major backend API update broke all frontend tests, leading to 172 hours of developer time spent on fixes.

#2about 5 minutes

Validating API contracts at three distinct levels

Implement robust API tests by validating status codes, response schemas, and specific required data for frontend features.

#3about 4 minutes

Enforcing contracts by treating code as the contract

Replace static documentation with executable contract tests and share them with your partner team to improve debugging and collaboration.

#4about 9 minutes

Simulating contracts to decouple from external APIs

Use a mock server to increase development stability, improve test reliability, and allow frontend work to proceed even when the real API is down.

#5about 1 minute

A summary of the three-step contract testing process

A recap of the validate, enforce, and simulate strategy for managing dependencies on external APIs.

#6about 3 minutes

Q&A on mocking tools and handling API versioning

The speakers answer audience questions about using WireMock versus Karate for mocking, handling API versioning, and managing credentials.

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