Ensuring compatibility with the LSP
The LSP is yet another fundamental aspect of robust object-oriented design. It advocates for the interchangeability of subclasses without affecting the superclass’ methods contracts, or, in other words, its interface. This principle, named after computer scientist Barbara Liskov, stipulates that objects of a superclass can be replaced by objects of its subclasses without altering any of the desirable properties of the application.
To implement the LSP effectively, subclasses must maintain the behavioral expectations set by their superclasses. For instance, if a superclass has a method that accepts an input range and guarantees an output, any subclass should honor these operational boundaries. Consider a weapon class in a game that calculates damage based on certain attributes. If a subclass overrides this method but introduces new, unexpected side effects or constraints (such as ignoring input parameters or altering unrelated state), it...
