An interface, trait, protocol or abstract class with one implementation
Code nobody needs: one of the ways AI coding agents bloat software, from lessloc's pattern catalog. lessloc catches it as single-impl.
What makes an interface or abstract class with one implementation a bad practice?
The standards that call it a bad practice: Fowler: Speculative Generality (Collapse Hierarchy); Ousterhout, A Philosophy of Software Design: classitis.
What does lessloc do about an interface or abstract class with one implementation?
lessloc catches it as single-impl.
single-impl(tier 2): An interface or abstract class with one implementation, or an abstract class with none.
Related patterns
The other patterns in Code nobody needs:
- Options, flags, parameters or config for needs nobody named: lessloc gives every session a rule against it and catches it as
mode-flag. - Wrappers that only forward; barrel files that only re-export: lessloc catches it as
wrapper. - A new function or import that nothing calls or tests: lessloc catches it as
unused(ruff adds unused variables). - Obsolete code kept behind a guard or flag instead of deleted: lessloc gives every session the rule: delete what the change makes dead.
- Tombstones: lessloc catches it as
history. - Stubs and fake success: lessloc catches it as
stub; it asks to finish the code or to tell the user what is not real yet. - Placeholders: # ... existing code ..., "your code here": lessloc catches it as
placeholderand refuses it before it lands. - Commented-out code: lessloc catches it as
commented-outand refuses it before it lands. - Debug leftovers: lessloc catches it as
debug-leftover. - A demo __main__ block or demo folder nobody asked for: lessloc catches it as
demo-codeandnew-folder. - Hand-written boilerplate a language feature writes: lessloc catches it as
simpler. - A one-line helper used once: lessloc catches it as
single-use. - TODO and FIXME left behind: lessloc catches it as
todo; it asks to finish the work, or to record known debt asshortcut:and tell the user.