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react-is
Advanced tools
The react-is package is a collection of utilities that allow you to determine the type of a React element. It is useful for type-checking elements and for working with React's different types of components and elements in a more abstract way.
Type-checking elements
This feature allows you to check if a value is a valid React component type or a React element. It's useful for validating props or for conditional rendering logic.
import { isValidElementType, isElement } from 'react-is';
const MyComponent = () => <div>Hello World</div>;
const myElement = <MyComponent />;
const validType = isValidElementType(MyComponent); // true
const elementCheck = isElement(myElement); // true
Identifying different element types
This feature allows you to identify specific element types like fragments, strict mode wrappers, and portals. This can be useful when writing custom rendering logic or testing components.
import { isFragment, isStrictMode, isPortal } from 'react-is';
const myFragment = <React.Fragment></React.Fragment>;
const myStrictMode = <React.StrictMode></React.StrictMode>;
const myPortal = ReactDOM.createPortal(<div />, document.body);
const fragmentCheck = isFragment(myFragment); // true
const strictModeCheck = isStrictMode(myStrictMode); // true
const portalCheck = isPortal(myPortal); // true
Working with Context
This feature allows you to check if an element is a Context Provider or a Context Consumer. This is particularly useful in higher-order components or in libraries that need to handle context-related elements.
import { isContextConsumer, isContextProvider } from 'react-is';
const MyContext = React.createContext();
const contextProviderCheck = isContextProvider(<MyContext.Provider value={null}></MyContext.Provider>); // true
const contextConsumerCheck = isContextConsumer(<MyContext.Consumer>{() => null}</MyContext.Consumer>); // true
The prop-types package is used for type-checking props passed to React components. It provides runtime type checking for React props and similar functionality for validating component inputs, but it does not offer the same utilities for identifying React element types as react-is.
Enzyme is a testing utility for React that makes it easier to assert, manipulate, and traverse your React Components' output. While it includes methods for type-checking and identifying components, it is more focused on testing utilities rather than providing a comprehensive set of type identifiers like react-is.
react-is
This package allows you to test arbitrary values and see if they're a particular React element type.
# Yarn
yarn add react-is
# NPM
npm install react-is
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
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
import React from "react";
import * as ReactIs from 'react-is';
ReactIs.isElement(<div />); // true
ReactIs.typeOf(<div />) === ReactIs.Element; // true
import React from "react";
import * as ReactIs from 'react-is';
ReactIs.isFragment(<></>); // true
ReactIs.typeOf(<></>) === ReactIs.Fragment; // true
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
import React from "react";
import * as ReactIs from 'react-is';
ReactIs.isStrictMode(<React.StrictMode />); // true
ReactIs.typeOf(<React.StrictMode />) === ReactIs.StrictMode; // true
19.1.0 (March 28, 2025)
useId
to use valid CSS selectors, changing format from :r123:
to «r123»
. #32001href
attribute is an empty string #31783getHoistableRoot()
didn’t work properly when the container was a Document #32321<!-- -->
) as a DOM container. #32250<script>
and <template>
tags to be nested within <select>
tags. #31837exports
field to package.json
for use-sync-external-store
to support various entrypoints. #25231unstable_prerender
, a new experimental API for prerendering React Server Components on the server #31724registerServerReference
in client builds to handle server references in different environments. #32534FAQs
Brand checking of React Elements.
The npm package react-is receives a total of 85,816,202 weekly downloads. As such, react-is popularity was classified as popular.
We found that react-is demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 2 open source maintainers collaborating on the project.
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