Open/Closed Principle

OCP

Kind: principle

Layer: Structural Core

Aliases: OCP, Open-Closed Principle

Record: architecture:open-closed

Severity: recommended

Scope: class, module, component

Canonical: Ontology

A design rule that a module gains new behavior by adding code at an extension point, leaving its existing code unchanged.

Listed in Architecture principles, after Dependency Inversion Principle (DIP) and before Liskov Substitution Principle (LSP).

Requires

• Abstraction
• Extension Points

Reinforces

• Plugin Architecture
• Strategy Pattern

Enables

• Feature Extension without Modification

Conflicts with

• Switch-Based Extension

In tension with

• Simplicity

Tensions

• Open/Closed Principle (OCP) / Simplicity

Contracts

• Extensibility Core

Violated by

• Switch-Based Extension

Refactored by

• Strategy Pattern
• Extension Points
• Plugin Architecture

Severity

• recommended

Category

• SOLID / Object-Oriented Design

Enforced by

• rules/eslint/closure-barrel-must-be-glob.eslint.rule.ts
• rules/eslint/require-self-registration.eslint.rule.ts

Reinforced by

• Dynamic Dispatch
• Runtime Extensibility
• Polymorphism
• Command Pattern
• State Pattern
• Chain of Responsibility Pattern
• Visitor Pattern
• Factory Pattern
• Factory Method Pattern
• Decorator Pattern
• Composite Pattern

Linked from

• The filesystem is the architecture
• The structural domain
• Runtime Discovery / Dynamic Binding
• Core Modular Design
• SOLID / Object-Oriented Design
• Behavioral Patterns
• Creational Patterns
• Structural Patterns
• Plugin / Extensibility / IoC
• Quality Attributes
• SOLID / Object-Oriented Design
• Architectural Clusters
• Severity levels
• The resolutions

in this codebase

• registerPage
• presentation/records
• presentation/records/records.barrel.ts