liskov-substitution-principle
Liskov Substitution Principle (LSP)
Overview
Subtypes must be substitutable for their base types without altering program correctness.
If S is a subtype of T, objects of type T can be replaced with objects of type S without breaking the program. Subclasses must honor the contracts of their parent classes.
When to Use
- Creating a class that extends another class
- Overriding methods from a parent class
- Implementing an interface
- Feeling like you need to throw exceptions in overridden methods
- Inheritance hierarchy feels "forced"
The Iron Rule
More from yanko-belov/code-craft
dont-repeat-yourself
Use when writing similar code in multiple places. Use when copy-pasting code. Use when making the same change in multiple locations.
84lazy-loading
Use when loading all data upfront. Use when initial page load is slow. Use when fetching data that might not be needed.
54keep-it-simple
Use when tempted to write clever code. Use when solution feels complex. Use when showing off skills instead of solving problems.
51separation-of-concerns
Use when component does too many things. Use when mixing data fetching, logic, and presentation. Use when code is hard to test.
44single-responsibility-principle
Use when creating or modifying classes, modules, or functions. Use when feeling pressure to add functionality to existing code. Use when class has multiple reasons to change.
39fail-fast
Use when handling errors. Use when tempted to catch and swallow exceptions. Use when returning default values to hide failures.
35