AI Testing
Testing LangChain Applications: Unit Testing Chains, Mocking LLMs, Eval Harnesses
LangChain applications are complex pipelines: prompts, chains, retrievers, tools, agents, and memory all interact. Testing them requires strategies that go beyond standard unit testing — you need to mock LLMs, test chains in isolation, and run eval harnesses that verify output quality over representative datasets. This guide covers all three layers.