copy-descriptor

What is copy-descriptor?

The copy-descriptor npm package is designed for copying property descriptors from one object to another. It allows for precise control over how properties are copied, including their enumerability, configurability, writability, and whether they are getters/setters. This can be particularly useful when you want to replicate the behavior of an object's properties without altering the original object.

What are copy-descriptor's main functionalities?

Copying a single property descriptor

This feature allows you to copy a single property descriptor from the source object to the target object. The code sample demonstrates copying the getter for the 'foo' property from the source object to the target object, then logging the descriptor of the 'foo' property on the target to show that it has been copied.

const copyDescriptor = require('copy-descriptor');
let target = {};
let source = { get foo() { return 'bar'; } };
copyDescriptor(target, source, 'foo');
console.log(Object.getOwnPropertyDescriptor(target, 'foo'));

Copying multiple property descriptors

This feature enables the copying of multiple property descriptors from the source object to the target object in a single call. The code sample shows how to copy both the 'foo' getter and the 'bar' value property from the source to the target, then logs the descriptors to demonstrate that both properties have been successfully copied.

const copyDescriptor = require('copy-descriptor');
let target = {};
let source = { get foo() { return 'bar'; }, bar: 'baz' };
copyDescriptor(target, source, ['foo', 'bar']);
console.log(Object.getOwnPropertyDescriptor(target, 'foo'));
console.log(Object.getOwnPropertyDescriptor(target, 'bar'));

Other packages similar to copy-descriptor

object-assign

object-assign is a package that allows for copying properties from one or more source objects to a target object. It is similar to copy-descriptor in that it facilitates the copying of properties, but it does not provide control over copying property descriptors with their specific characteristics like enumerability or configurability.

extend-shallow

extend-shallow is another npm package that offers functionality to copy properties from one object to another. It is designed for shallow copying, similar to Object.assign. While it allows for the extension of objects, it does not focus on copying property descriptors with their full definitions and characteristics, making it less precise than copy-descriptor for tasks requiring detailed control over property attributes.