How do you ensure subclasses follow LSP?

To ensure subclasses follow LSP:

• Subclasses should not override behavior in a way that breaks expected behavior.
• Subclasses should preserve the invariants and preconditions/postconditions of the

base class.

• Avoid overriding methods to throw exceptions for valid base class behavior.
• Use composition over inheritance if a subclass doesn’t strictly conform to the base

class behavior.

• Write unit tests to verify that the subclass behaves identically to the base class in all

valid scenarios.

✅ Ask yourself: Can this subclass be used anywhere the base class is used — without

surprises?