# `react-is`

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

## Installation

```sh

# Yarn

yarn add react-is

# NPM

npm install react-is

```

## Usage

### Determining if a Component is Valid

```js

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

ReactIs.isValidElementType(React.createFactory("div")); // true

```

### Determining an Element's Type

#### Context

```js

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

```js

import React from "react";

import * as ReactIs from 'react-is';

ReactIs.isElement(<div />); // true

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

```

#### Fragment

```js

import React from "react";

import * as ReactIs from 'react-is';

ReactIs.isFragment(<></>); // true

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

```

#### Portal

```js

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

```js

import React from "react";

import * as ReactIs from 'react-is';

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

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

```