Files
react/packages/react-is
Josh Story da6ba53b10 [UMD] Remove umd builds (#28735)
In React 19 React will finally stop publishing UMD builds. This is
motivated primarily by the lack of use of UMD format and the added
complexity of maintaining build infra for these releases. Additionally
with ESM becoming more prevalent in browsers and services like esm.sh
which can host React as an ESM module there are other options for doing
script tag based react loading.

This PR removes all the UMD build configs and forks.

There are some fixtures that still have references to UMD builds however
many of them already do not work (for instance they are using legacy
features like ReactDOM.render) and rather than block the removal on
these fixtures being brought up to date we'll just move forward and fix
or removes fixtures as necessary in the future.
2024-04-17 11:15:27 -07:00
..
2018-02-11 14:08:40 -08:00
2024-03-29 16:29:48 -04:00
2024-04-17 11:15:27 -07:00
2024-03-29 16:29:48 -04:00

react-is

This package allows you to test arbitrary values and see if they're a particular React element type.

Installation

# Yarn
yarn add react-is

# NPM
npm install react-is

Usage

Determining if a Component is Valid

import React from "react";
import * as ReactIs from "react-is";

class ClassComponent extends React.Component {
  render() {
    return React.createElement("div");
  }
}

const FunctionComponent = () => React.createElement("div");

const ForwardRefComponent = React.forwardRef((props, ref) =>
  React.createElement(Component, { forwardedRef: ref, ...props })
);

const Context = React.createContext(false);

ReactIs.isValidElementType("div"); // true
ReactIs.isValidElementType(ClassComponent); // true
ReactIs.isValidElementType(FunctionComponent); // true
ReactIs.isValidElementType(ForwardRefComponent); // true
ReactIs.isValidElementType(Context.Provider); // true
ReactIs.isValidElementType(Context.Consumer); // true

Determining an Element's Type

Context

import React from "react";
import * as ReactIs from 'react-is';

const ThemeContext = React.createContext("blue");

ReactIs.isContextConsumer(<ThemeContext.Consumer />); // true
ReactIs.isContextProvider(<ThemeContext.Provider />); // true
ReactIs.typeOf(<ThemeContext.Provider />) === ReactIs.ContextProvider; // true
ReactIs.typeOf(<ThemeContext.Consumer />) === ReactIs.ContextConsumer; // true

Element

import React from "react";
import * as ReactIs from 'react-is';

ReactIs.isElement(<div />); // true
ReactIs.typeOf(<div />) === ReactIs.Element; // true

Fragment

import React from "react";
import * as ReactIs from 'react-is';

ReactIs.isFragment(<></>); // true
ReactIs.typeOf(<></>) === ReactIs.Fragment; // true

Portal

import React from "react";
import ReactDOM from "react-dom";
import * as ReactIs from 'react-is';

const div = document.createElement("div");
const portal = ReactDOM.createPortal(<div />, div);

ReactIs.isPortal(portal); // true
ReactIs.typeOf(portal) === ReactIs.Portal; // true

StrictMode

import React from "react";
import * as ReactIs from 'react-is';

ReactIs.isStrictMode(<React.StrictMode />); // true
ReactIs.typeOf(<React.StrictMode />) === ReactIs.StrictMode; // true