babel-plugin-transform-react-flow-handled-props

Generates handledProps from defaultProps and propTypes during the build :sparkles:

Installation

$ npm install --save-dev babel-plugin-transform-react-flow-handled-props

Story

This plugin was originally created for Semantic React package. It implements useful pattern with handled props by component, using it you can let down unhandled props to child component.

Motivation

Let's take an example from real life. There are cases when you need to pass some of the props to the child component. The simplest way is to use the destruction of the object.

const Foo = (props) => {
  const { className, ...rest } = props
  const classes = classNames(className, 'foo')

  return <div {...rest} className={classes} />
}

The solution is simple and straightforward, but what if the props that will need to be handled is not used in the method? We still need to specify it explicitly.

class Foo extends React.Component {
  handleClick = (e) => this.props.onClick(e)

  render() {
    const { className, onClick, ...rest } = this.props
    const classes = classNames(className, 'foo')

    return <div {...rest} className={classes} onClick={this.handleClick} />
  }
}

And what if there are a lot of components? Yes, we will come to another solution, it's to rely on the React's propTypes. It's a good and logical solution.

class Foo extends React.Component {
  static propTypes = {
    className: PropTypes.string,
    onClick: PropTypes.func,
  }

  handleClick = (e) => this.props.onClick(e)

  render() {
    const { className } = this.props
    const classes = classNames(className, 'foo')
    const rest = _.omit(this.props, _.keys(Foo.propTypes))

    return <div {...rest} className={classes} onClick={this.handleClick} />
  }
}

Looks pretty good? But, there is only one problem, we don't need propTypes in the production build. We can take the plugin to remove them, but then our solution will be broken? It's possible that you already use this approach, but you can't get rid of propTypes in the your bundle. This plugin solves the described problem, so you can rely on propTypes and at the same time remove them from the production build.

class Foo extends React.Component {
  static propTypes = {
    className: PropTypes.string,
    onClick: PropTypes.func,
  }

  handleClick = (e) => this.props.onClick(e)

  render() {
    const { className } = this.props
    const classes = classNames(className, 'foo')
    const rest = _.omit(this.props, Foo.handledProps)

    return <div {...rest} className={classes} onClick={this.handleClick} />
  }
}

Example transform

PropTypes

In

const Baz = (props) => (
  <div {...props} />
)

Baz.propTypes = {
  children: PropTypes.node,
  className: PropTypes.string,
}

Out

const Baz = (props) => (
  <div {...props} />
)

Baz.handledProps = ['className', 'children'];

Baz.propTypes = {
  children: PropTypes.node,
  className: PropTypes.string,
}

Flow Props

In

// @flow

import * as React from 'react';
import PropTypes from 'prop-types';

type Props = {
  name?: string,
  _text?: string,
  'aria-describedby'?: string,
  children?: React.Node
}

class Baz extends React.Component<Props> {

  render() {
    return <div {...this.props} />;
  }
}

export default Baz;

Out

// @flow

import * as React from 'react';

type Props = {
  name?: string;
  _text?: string;
  'aria-describedby'?: string;
  children?: React.Node;
};

class Baz extends React.Component<Props> {

  render() {
    return <div {...this.props} />;
  }
  static handledProps = ['_text', 'aria-describedby', 'children', 'name'];
}

export default Baz;

note: flow type must be named Props

Usage

Via .babelrc (Recommended)

.babelrc

{
  "plugins": ["transform-react-flow-handled-props"]
}

Via CLI

$ babel --plugins transform-react-flow-handled-props script.js

Via Node API

require("babel-core").transform("code", {
  plugins: ["transform-react-flow-handled-props"]
});

Options

ignoredProps

This options allows to ignore some props, this will allow to not add them to handledProps.

{
  "plugins": ["transform-react-flow-handled-props", { "ignoredProps": ["children"] }]
}

In

const Baz = (props) => (
  <div {...props} />
)

Baz.propTypes = {
  children: PropTypes.node,
  className: PropTypes.string,
}

Out

const Baz = (props) => (
  <div {...props} />
)

Baz.handledProps = ['className'];

Baz.propTypes = {
  children: PropTypes.node,
  className: PropTypes.string,
}

Is it safe?

Absolutely :sunglasses: You can also use in production with babel-plugin-transform-react-remove-prop-types and it will work perfectly.

const Baz = (props) => {
  const rest = _.omit(props, Baz.handledProps)

  return (
    <div {...props}>
      <Foo {...rest} />
    </div>
  )
}

License

MIT