babel-plugin-optimize-react

babel-plugin-optimize-react

This Babel 7 plugin optimizes React hooks by transforming common patterns into more effecient output when using with tools such as Create React App. For example, with this plugin the following output is optimized as shown:

// Original
var _useState = Object(react__WEBPACK_IMPORTED_MODULE_1_["useState"])(Math.random()),
    _State2 = Object(_Users_gaearon_p_create_rreact_app_node_modules_babel_runtime_helpers_esm_sliceToArray_WEBPACK_IMPORTED_MODULE_0__["default"])(_useState, 1),
    value = _useState2[0];
    
// With this plugin
var useState = react__WEBPACK_IMPORTED_MODULE_1_.useState;
var __ref__0 = useState(Math.random());
var value = __ref__0[0];

Named imports to hooks get transformed

// Original
import React, {useState} from 'react';

// With this plugin
import React from 'react';
const {useState} = React;

Array destructuring transform for React's built-in hooks

// Original
const [counter, setCounter] = useState(0);

// With this plugin
const __ref__0 = useState(0);
const counter = __ref__0[0];
const setCounter = __ref__0[1];

React.createElement becomes a hoisted constant

// Original
import React from 'react';

function MyComponent() {
  return React.createElement('div', null, 'Hello world');
}

// With this plugin
import React from 'react';
const __reactCreateElement__ = React.createElement;

function MyComponent() {
  return __reactCreateElement__('div', null, 'Hello world');
}