Command Pattern Explained: Encapsulating Requests for Flexible, Decoupled Code

The Command Pattern is a behavioral design pattern that wraps requests as standalone objects, enabling developers to parameterize, queue, log, and undo operations. It involves four key roles: the Command interface, ConcreteCommand implementations, an Invoker that triggers commands, and a Receiver that carries out the actual work. A practical example using TypeScript demonstrates a remote controller toggling a light, with full support for undo functionality via a command history stack. The pattern also scales to advanced use cases such as macro commands, transaction managers, and async task queues. While it promotes clean separation of concerns and open-closed design, it does introduce additional classes and increased complexity in managing command histories.