Overview
Function implementations fail when they handle only the happy path — validating expected inputs but returning undefined behavior for unexpected inputs, letting exceptions propagate without context, and leaving behavior undocumented so the next developer has to read the implementation to understand what the function does. Production functions must be defensive, documented, and deterministic.
The Function Implementation Framework generates implementations that handle all input states, document behavior explicitly, and fail with informative errors rather than silently returning wrong results.
Key Features
Contract documentation before implementation
Input validation by type with specific patterns
Informative error message standard
Edge case handling table