What are advanced TypeScript decorators and how do I use them?

What are advanced TypeScript decorators and how do I use them?

Advanced TypeScript decorators are special functions that can modify classes, methods, or properties. They allow for adding metadata, logging, and more. Would you like to see an example?

Yes, please provide an example of a method decorator.

Sure! Here's a simple method decorator that logs the execution time of a method:

function LogExecutionTime(target: any, propertyName: string, descriptor: PropertyDescriptor) {
    const originalMethod = descriptor.value;
    descriptor.value = function (...args: any[]) {
        const start = performance.now();
        const result = originalMethod.apply(this, args);
        const end = performance.now();
        console.log(`Execution time for ${propertyName}: ${end - start} ms`);
        return result;
    };
}

How can I apply this decorator to a method?

You can apply the decorator by prefixing your method with @LogExecutionTime. For example:

class Example {
    @LogExecutionTime
    someMethod() {
        // method logic
    }
}

Are there any limitations or best practices when using decorators?

Yes, decorators can make code harder to understand if overused. It's best to use them for cross-cutting concerns like logging or validation, and to keep their logic simple.