What is @babel/plugin-transform-destructuring?
The @babel/plugin-transform-destructuring npm package is a plugin for Babel, a JavaScript compiler, that enables the transformation of destructuring assignments and rest properties in JavaScript code. This allows for more concise and readable code, especially when dealing with objects or arrays. The plugin is part of the larger Babel ecosystem, which helps developers write next-gen JavaScript today.
What are @babel/plugin-transform-destructuring's main functionalities?
Object Destructuring
Transforms object destructuring syntax into a format that can be understood by environments that do not support ES2015 or later. This feature allows for extracting properties from objects and assigning them to variables in a single statement.
const { a, b } = { a: 1, b: 2 };
Array Destructuring
Enables transformation of array destructuring, which allows for a similar concise syntax for arrays as for objects, extracting values from arrays directly into variables.
const [a, b] = [1, 2];
Nested Destructuring
Supports nested destructuring, which is useful for extracting deeply nested properties or values from objects or arrays into variables at various levels of depth.
const { a: { b, c } } = { a: { b: 1, c: 2 } };
Default Values
Allows for setting default values in destructuring assignments, which is particularly useful when the expected property might not exist in the source object or array.
const { a = 10, b = 5 } = { a: 3 };
Other packages similar to @babel/plugin-transform-destructuring
babel-plugin-transform-es2015-destructuring
This package offers similar functionality to @babel/plugin-transform-destructuring but is specifically targeted at transforming ES2015 destructuring syntax. It's part of the older Babel 6 ecosystem and has been superseded by the more general @babel/plugin-transform-destructuring in Babel 7.
babel-preset-env
While not a direct equivalent, babel-preset-env includes @babel/plugin-transform-destructuring among many other plugins. It automatically determines the Babel plugins and polyfills you need based on your supported environments. It's a more comprehensive solution for writing next-gen JavaScript.
@babel/plugin-transform-destructuring
Compile ES2015 destructuring to ES5
Examples
In
let arr = [1,2,3];
let {x, y, z} = arr;
Out
var arr = [1, 2, 3];
var x = arr.x,
y = arr.y,
z = arr.z;
Installation
npm install --save-dev @babel/plugin-transform-destructuring
Usage
Via .babelrc
(Recommended)
.babelrc
{
"plugins": ["@babel/plugin-transform-destructuring"]
}
Via CLI
babel --plugins @babel/plugin-transform-destructuring script.js
Via Node API
require("@babel/core").transform("code", {
plugins: ["@babel/plugin-transform-destructuring"]
});
Options
loose
boolean
, defaults to false
.
Enabling this option will assume that what you want to destructure is an array and won't use Array.from
on other iterables.
useBuiltIns
boolean
, defaults to false
.
Enabling this option will use Object.assign
directly instead of the Babel's extends
helper.
Example
.babelrc
{
"plugins": [
["@babel/plugin-transform-destructuring", { "useBuiltIns": true }]
]
}
In
var { ...x } = z;
Out
var _z = z,
x = Object.assign({}, _z);