26.0.0 • Public • Published

A babel plugin to generate React PropTypes definitions from Flow type declarations.

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With this input:

var React = require('react');
export type Qux = {baz: 'literal'};
import type SomeExternalType from './types';
type FooProps = {
  an_optional_string?: string,
  a_number: number,
  a_boolean: boolean,
  a_generic_object: Object,
  array_of_strings: Array<string>,
  instance_of_Bar: Bar,
  anything: any,
  mixed: mixed,
  one_of: 'QUACK' | 'BARK' | 5,
  one_of_type: number | string,
  nested_object_level_1: {
    string_property_1: string,
    nested_object_level_2: {
      nested_object_level_3: {
        string_property_3: string,
      string_property_2: string,
  should_error_if_provided: void,
  intersection: {foo: string} & { bar: number } & Qux,
  some_external_type: SomeExternalType,
  some_external_type_intersection: {foo: string} & SomeExternalType,
export default class Foo extends React.Component {
  props: FooProps

The output will be:

var React = require('react');
var babelPluginFlowReactPropTypes_proptype_Qux = {
  baz: bpfrp_PropTypes.oneOf(['literal']).isRequired
export default class Foo extends React.Component {}
Foo.propTypes = {
  an_optional_string: bpfrp_PropTypes.string,
  a_number: bpfrp_PropTypes.number.isRequired,
  a_boolean: bpfrp_PropTypes.bool.isRequired,
  a_generic_object: bpfrp_PropTypes.object.isRequired,
  array_of_strings: bpfrp_PropTypes.arrayOf(bpfrp_PropTypes.string.isRequired).isRequired,
  instance_of_Bar: function () {
    return (typeof Bar === 'function' ? bpfrp_PropTypes.instanceOf(Bar).isRequired : bpfrp_PropTypes.any.isRequired).apply(this, arguments);
  anything: (props, propName, componentName) => {
    if (!, propName)) {
      throw new Error(`Prop \`${propName}\` has type 'any' or 'mixed', but was not provided to \`${componentName}\`. Pass undefined or any other value.`);
  mixed: (props, propName, componentName) => {
    if (!, propName)) {
      throw new Error(`Prop \`${propName}\` has type 'any' or 'mixed', but was not provided to \`${componentName}\`. Pass undefined or any other value.`);
  one_of: bpfrp_PropTypes.oneOf(['QUACK', 'BARK', 5]).isRequired,
  one_of_type: bpfrp_PropTypes.oneOfType([bpfrp_PropTypes.number, bpfrp_PropTypes.string]).isRequired,
  nested_object_level_1: bpfrp_PropTypes.shape({
    string_property_1: bpfrp_PropTypes.string.isRequired,
    nested_object_level_2: bpfrp_PropTypes.shape({
      nested_object_level_3: bpfrp_PropTypes.shape({
        string_property_3: bpfrp_PropTypes.string.isRequired
      string_property_2: bpfrp_PropTypes.string.isRequired
  should_error_if_provided: (props, propName, componentName) => {
    if (props[propName] != null) {
      throw new Error(`Invalid prop \`${propName}\` of value \`${props[propName]}\` passed to \`${componentName}\`. Expected undefined or null.`);
  intersection: bpfrp_PropTypes.shape({
    foo: bpfrp_PropTypes.string.isRequired,
    bar: bpfrp_PropTypes.number.isRequired,
    baz: bpfrp_PropTypes.oneOf(['literal']).isRequired
  some_external_type: function () {
    return (typeof bpfrp_babelPluginFlowReactPropTypes_proptype_SomeExternalType === 'function' ? bpfrp_babelPluginFlowReactPropTypes_proptype_SomeExternalType.isRequired ? bpfrp_babelPluginFlowReactPropTypes_proptype_SomeExternalType.isRequired : bpfrp_babelPluginFlowReactPropTypes_proptype_SomeExternalType : bpfrp_PropTypes.shape(bpfrp_babelPluginFlowReactPropTypes_proptype_SomeExternalType).isRequired).apply(this, arguments);
  some_external_type_intersection: bpfrp_PropTypes.shape(Object.assign({}, {
    foo: bpfrp_PropTypes.string.isRequired
  }, bpfrp_babelPluginFlowReactPropTypes_proptype_SomeExternalType === bpfrp_PropTypes.any ? {} : bpfrp_babelPluginFlowReactPropTypes_proptype_SomeExternalType)).isRequired
import bpfrp_PropTypes from 'prop-types';
export { babelPluginFlowReactPropTypes_proptype_Qux };
import { bpfrp_babelPluginFlowReactPropTypes_proptype_SomeExternalType } from './types';


Starting in 14.0.0, we output ES6 import/export statements by default. The deadCode option (explained below) will cause it to use common.js modules instead.

In version 25.0.0 and onward, we only support babel 7. Install version 24.x.x if you're using babel 6.

The reaason for the high major versions is that any change to the prop type output, including adding new checks that previously produced no output, impact users of this plugin. Check the changelog to see what's changed at each version.


This plugin searches for a React components using type declaration. Works with functional components and ES6 classes. React.createClass is not currently supported.


First install the plugin:

npm install --save-dev babel-plugin-flow-react-proptypes

Also install the prop-types package. This is required for React >=15.5.0. For earlier React versions you can use version 0.21.0 of this plugin, which doesn't use the prop-types package.

npm install --save prop-types

Then add it to your babelrc:

  "presets": ["..."],
  "plugins": ["flow-react-proptypes"]

To save some bytes in production, you can also only enable it in development mode.

  "presets": ["..."],
  "env": {
    "development": {
      "plugins": ["flow-react-proptypes"]


The deadCode option (disabled by default) adds a predicate to the code allowing both your propTypes definitions and potentially the entire 'prop-types' package to be excluded in certain builds. Unlike specifying this plugin in the development env, mentioned above, this also works for packages published to npm.

  "plugins"[["flow-react-proptypes", { "deadCode": true }]]

The value of true is short for process.env.NODE_ENV === 'production'. You can alternatively pass any JavaScript expression. If the expression returns a truthy value, then the propTypes will be removed. This works because e.g. webpack will subsitute the value of process.env.NODE_ENV with 'production', resulting in the condition being 'production' === 'production', and then a minifer sees that the code we're generating can't be executed, and strips it, and the require('prop-types') code out of the final bundle.

Note: In dead code mode, we use require/module.exports instead of ES6 modules.

Example of specifying a custom expression:

  "plugins"[["flow-react-proptypes", { "deadCode": "__PROD__" }]]


The useESModules option forces this plugin to output ES6 modules, even if the deadCode option is enabled. Your bundler will be responsible for removing the dead code.


This plugin isn't perfect. You can disable it for an entire file with this directive (including quotes):

'no babel-plugin-flow-react-proptypes';

Specifically for react-native you can disable this for files in node_modules with the ignoreNodeModules config option.

  "presets": ["..."],
  "plugins": [["flow-react-proptypes", { "ignoreNodeModules": true }]]

If you already have other plugins in plugins section. It is important to place flow-react-proptypes before the following plugins:

  • transform-class-properties
  • transform-flow-strip-types

If you're using the 'react' or 'flow' presets, you don't need to do anything special.

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npm i babel-plugin-flow-react-proptypes

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