functionsparing
Functionsparing is a software engineering concept that describes preserving the outward behavior of a set of functional interfaces while the underlying implementations are replaced, upgraded, or refactored. The core idea is to maintain functional parity and API compatibility so downstream clients experience no or minimal disruption during migrations or optimizations.
In practice, function sparing is implemented with wrappers, adapters, or shims that preserve the original function
Key patterns include the use of facade and adapter designs to isolate incompatible changes, contract testing
Use cases often involve public APIs, library ecosystems, or service interfaces where widespread consumer code depends