How do I use class decorators in TypeScript?

Can you explain what class decorators are in TypeScript?

Class decorators are special functions that can modify or enhance classes in TypeScript. They are applied to a class declaration and can be used to add metadata, modify the class prototype, or even replace the class.

How do I create a simple class decorator?

To create a class decorator, define a function that takes a class as an argument. For example:

function MyDecorator(constructor: Function) {
    console.log('Class decorated:', constructor);
}

@MyDecorator
class MyClass {}

Can I pass parameters to a class decorator?

Yes, you can create a factory function that returns a decorator. For example:

function MyDecorator(param: string) {
    return function(constructor: Function) {
        console.log('Class decorated with param:', param);
    };
}

@MyDecorator('Hello')
class MyClass {}

What are some common use cases for class decorators?

Common use cases include adding metadata for dependency injection, logging class instantiation, or enforcing certain behaviors across classes.