Testing

This skill provides guidance on testing philosophy and practices, emphasizing tests as specifications and API design through TDD.

Core Philosophy

Tests as Executable Specifications

Tests are not just verification tools — they are executable specifications that document how the system should behave. A well-written test suite serves as living documentation.

Tests as API Consumers

Tests are the first users of your code's APIs. This is why TDD is valuable: you design the API by thinking about the consumer first, before thinking about implementation.

When writing tests:

Consider what interface would be most convenient for the caller
Let the test drive the API design
If the test is awkward to write, the API is awkward to use