is-react-component

A more reliable test of whether a function or constructor is a React Component

Alternatives to this lib tend to check for the presence of the createElement substring inside of the stringified function. This lib––on the other hand––is equipped to parse the stringified function and traverse it for the presence of createElement as an actual 'CallExpression' node. This results in fewer false positives. Results are internally memoized 🎉

Installation

npm i is-react-component

Usage

import React, {Component} from 'react'
import isReactComponent from 'is-react-component'
 
const SomeFunctionalComponent = () => <div>Hello World</div>
isReactComponent(SomeFunctionalComponent) // true
 
class SomeClassComponent extends Component {
  render() {
    return <div>Hello World</div>
  }
}
isReactComponent(SomeClassComponent) // true
 
const SomeNonComponent = () => console.log('Hello World')
isReactComponent(SomeNonComponent) // false

Something to note

There is no perfect solution to this problem. React Components are not marked as such. There are edge cases to consider: namely, components reference other components. You could have a component that instantiates other components without ever calling createElement. Another way that this check gets hazy is when you have a function that conditionally returns a Component instance or a value of another type. If you run into a need for this or comparable libraries, you might be architecting something hacky and unsafe––but you only live once, so enjoy!

License

MIT