babel-plugin-transform-react-pure-components
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Optimize React code by transforming pure components into stateless functional components.
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# babel-plugin-transform-react-pure-components
Optimize React code by transforming pure components into stateless functional components.
[](https://travis-ci.org/basilfx/babel-plugin-transform-react-pure-components)
## Introduction
In React, a pure component is a component that renders the same given the same properties and state. In addition stateless functions can replace class-based components that only rely on properties.
This Babel plugin transforms class-based components into stateless functions, if:
- The class only contains a `render()` method.
- Does not define additional (static) properties.
- Is stateless.
## Example
In:
```js
class MyComponent extends React.Component {
static propTypes = {
className: React.PropTypes.string.isRequired
};
render() {
return (
<div className={this.props.className}>
...
</div>
);
}
}
```
Out:
```js
function MyComponent(props) {
return (
<div className={props.className}>
...
</div>
);
}
MyComponent.propTypes = {
className: React.PropTypes.string.isRequired
};
```
## Installation
```sh
$ npm install babel-plugin-transform-react-pure-components
```
## Usage
### Via `.babelrc` (Recommended)
**.babelrc**
```json
{
"plugins": ["transform-react-pure-components"]
}
```
### Via CLI
```sh
$ babel --plugins transform-react-pure-components script.js
```
### Via Node API
```js
require("babel-core").transform("code", {
plugins: ["transform-react-pure-components"]
});
```
## Options
The options below may not improve performance, and may produce unpredictable results.
* `pureComponents = false` — Transform components extending `React.PureComponent` classes (this effectively converts them back to `React.Component`).
* `assignDefaultProps = false` — When true, use `Object.assign(defaultProps, props)` instead of an additional static definition. Set to `hoist` to hoist them to the parent scope (can be useful in combination with [babel-plugin-transform-react-remove-prop-types](https://github.com/oliviertassinari/babel-plugin-transform-react-remove-prop-types)).
## Benchmarks
According to [this article](https://medium.com/missive-app/45-faster-react-functional-components-now-3509a668e69f), a performance boost can be expected. However, [another article](https://moduscreate.com/react_component_rendering_performance/) shows no performance boost. Nonetheless, functional stateless components [may allow](https://twitter.com/dan_abramov/status/755343749983657986) for optimizations in the future.
In a (non-scientific) [benchmark](https://gist.github.com/basilfx/bd0e5ea9ebda1b40d34bf23bd3dd7835), using this plugin yields an improvement of 22% over a class-based component (React 16, 10.000 instantiations of a component, babel-preset-env @ Chrome 59).