Decraft - Smart TypeScript Decorators

Decraft is a user-friendly npm package that simplifies the creation of TypeScript decorators, significantly enhancing their power and readability. With Decraft, crafting intuitive and efficient decorators is a streamlined and enjoyable experience.

Starting from the end - How does you use the decorators?

Lets say that we created a decorator named @myDecorator. Those are all of the ways that we can use the same decorator.

We don't need to create a new decorator for each case, we can just use the same one for all of those cases.

@myDecorator

The classic way to use decorators. Just put it above a class method.

class MyClass {
	@myDecorator
	func(...params) {
		// code
	}
}

@myDecorator(...args)

We can also pass arguments to our decorator.

class MyClass {
	@myDecorator(...args)
	func(...params) {
		// code
	}
}

myDecorator(func, args)

Whooho, This is not a decorator!

You are right. But one of the issues with decorators is that we can't use them in some cases. For example for callbacks or functions outside of a class.

So with decraft, we allow you to use some hacks.

const func = myDecorator((...params) => {
	// code
}, ...args);

or another example:

function _func(...params) {
  // code
}

const func = myDecorator(_func, ...args)

myDecorator(...args)(func)

We allow also a different approach for readability.

const func = myDecorator(...args)((...params) => {
	// code
});

How to create a decorator?

It's pretty straightforward. We call the decorator function and pass as a generic a list of types that will be used for the decorator arguments.

Then we pass a callback which will be called each time we create the function (or the object it exists in).

It may also return a function, and this function will replace the function that the decorator is used on.

const  myDecorator  =  decorator<[...DecoratorParamsTypes]>((func, decoratorParams) => {
	// The function that we return here will replace the function that it's being used on
	return (...args:  any[]) => {
		// We're doing nothing, just calling the function
		return  func(...args);
	};

	// If we prefer, we can also return nothing and the decorator function will not replace the function that it's being used on
});

Our best practices

1. We still have several type issues, so we recommend to check that you really got the params you wanted to get.
2. Don't return a function with different type that the one you got. TypeScript not updating the function types right now when using this decorator.
3. When using decorator as a function like this: myDecorator(func, ...args) or myDecorator(...args)(func) you should set a type to the variable it's assigned to. We return any right now as a type.