how to set displayName in a functional component [React]

Question

I know that setting the displayName is sometimes required especially when you're dealing with production builds. I want to know how to set it using my functional component - is it possible/allowed?

Here's what I've got in my class component:

const MyComponent = React.createClass({
  displayName: 'HeyHey',

  render: function() {
    console.log(this.displayName);
  }
});

How do I do the same thing inside a stateless component?

Answer 1

The docs for displayName say

The displayName string is used in debugging messages. Usually, you don’t need to set it explicitly because it’s inferred from the name of the function or class that defines the component. You might want to set it explicitly if you want to display a different name for debugging purposes or when you create a higher-order component, see Wrap the Display Name for Easy Debugging for details.

In your case, you would simply use

const MyComponent = (props) => { ... }

MyComponent.displayName = 'HeyHey'

---

Or you can use Object.assign

const MyComponent =
  Object.assign
    ( props => { ... }
    , { displayName: 'HeyHey' }
    )

Answer 2

Figured it out

const MyComponent = props => {
  return (
    <p>How you doin?</p>
  )
}

MyComponent.displayName = "MyComponent"

Answer 3

React either needs displayName for functional components when they're defined as arrow functions, or the name of the function itself.
So for arrow functions:

const SomeComponent = () => <p>I come from an arrow function</p>

SomeComponent.displayName = 'HeyHey'

If you use a function, it'll use its name as displayName without having to define it separately:

function HeyHey() { return <p>I come from a non-arrow function!</p> }