decoratory v0.2.0

Decoratory

Simple and easy to use utility decorators for TypeScript projects. Many decorators are inspired by decorators from other languages (e.g., Java).

Installation

$ npm i decoratory

Usage

This package provides several decorators for usage in your TypeScript projects:

Deprecated

If you want to mark a method as deprecated, u can annotate it with @Deprecated

import { Deprecated } from "decoratory";

class MyClass {
    @Deprecated
    public deprecatedMethod() {
        // ...
    }
}

new MyClass().deprecatedMethod(); // This will print a deprecation warning to the console

If you want to provide your own deprecation message, you can do that by using @Deprecated with an extra argument:

import { Deprecated } from "decoratory";

class MyClass {
    @Deprecated("Custom Message")
    public deprecatedMethod() {
        // ...
    }
}

new MyClass().deprecatedMethod(); // This will print "Custom Message" to the console

Readonly

If you want to ensure, that a property can only be assigned once, you can use the @Readonly decorator:

import { Readonly } from "decoratory";

class MyClass {
    @Readonly
    public foo = 24;

    public myFunction() {
        this.foo = 1337;
    }
}

new MyClass().myFunction(); // This will throw a TypeError, since `MyClass.foo` cannot be reassigned

Observe

You can observe all changes (re-assignments) to a property by using the @Observe decorator:

import { Observe } from "decoratory";

class MyClass {
    @Observe
    public foo = 42;
}

Now, all changes to MyClass.foo will be logged to the console. To perform certain actions on reassignment, you can provide a custom callback to the decorator, which will get called with the new value upon each reassignment:

import { Observe } from "decoratory";

function observeCallback(newValue: unknown) {
    console.log(`setting value to ${newValue}`);
}

class MyClass {
    @Observe(observeCallback)
    public foo = 42;
}