Last Revision — April 19, 2022
1 Min Read
Excessive Exposure
Couplers
Data
Within a Class
- Insider Trading (causes)
- Feature Envy (causes)
- Message Chain (causes)
- Mutable Data (co-exist)
Joshua Kerievsky in cheatsheet (2005): "Smells to Refactorings Cheatsheet"
Unnecessarily exposing internal details is an Indecent Exposure code smell. The methods and variables of a class that works only with other same class methods should be kept private.
Otherwise, it might lead to Insider Trading or Feature Envy code smells. One should always strive to hide as many variables and methods from other classes as possible. Exposing irrelevant code contributes to the complexity of a design.
The developer could have a habit of creating all the methods public at first but then forgets to change the access levels to appropriate ones.
Fields accessible from outside the class baits for unnecessary coupling issues.
There is no need to expose all information to everyone.
Variable count is accessible by its name and can be freely changed.
@dataclass
class Counter:
count: int = field(init=False)
def bump(self) -> None:
self.count += 1
counter = Counter()
counter.bump()
print(f"Count: {counter.count}")Variable count is accessible only via exposed methods and is pseudo-protected from external direct changes.
@dataclass
class Counter:
__count: int = field(init=False)
@property
def count() -> int:
return self.__count
def bump(self) -> None:
self.__count += 1
def reset(self) -> None:
self.__count = 0
counter = Counter()
counter.bump()
print(f"Count: {counter.count}")