@babel/plugin-transform-react-constant-elements
This plugin can speed up reconciliation and reduce garbage collection pressure by hoisting React elements to the highest possible scope, preventing multiple unnecessary reinstantiations.
Example
In
const Hr = () => {
return <hr className="hr" />;
};
Out
const _ref = <hr className="hr" />;
const Hr = () => {
return _ref;
};
Deopts
-
Spread Operator
<div {...foobar} /> -
Refs
<div ref="foobar" /> <div ref={node => this.node = node} /> Mutable Properties
See https://github.com/facebook/react/issues/3226 for more on this
<div style={{width: 100}} />
Installation
npm install --save-dev @babel/plugin-transform-react-constant-elements
Usage
With a configuration file (Recommended)
{
"plugins": ["@babel/plugin-transform-react-constant-elements"]
}
Options
allowMutablePropsOnTags
Array<string>, defaults to []
If you are using a particular library (like react-intl) that uses object properties, and you are sure that the element won't modify its own props, you can whitelist the element so that objects are allowed.
This will skip the Mutable Properties deopt.
{
"plugins": [
["@babel/plugin-transform-react-constant-elements", {"allowMutablePropsOnTags": ["FormattedMessage"]}],
]
}
You can read more about configuring plugin options here
Via CLI
babel --plugins @babel/plugin-transform-react-constant-elements script.js
Via Node API
require("@babel/core").transform("code", {
plugins: ["@babel/plugin-transform-react-constant-elements"]
});