Is there any advantage of having a method as static?

Question

I am using Webstorm and I wrote a React component, my code looks like:

async onDrop( banner, e ) {
    banner.classList.remove( 'dragover' );
    e.preventDefault();

    const file = e.dataTransfer.files[ 0 ], reader = new FileReader();
    const { dispatch } = this.props;

    const result = await this.readFile( file, reader );

    banner.style.background = `url( ${ result } ) no-repeat center`;
    dispatch( addLayer( file ) );

    return false;
}


@isImage( 0 )
readFile( file, reader ) {
    reader.readAsDataURL( file );

    return new Promise( function ( resolve, reject ) {
        reader.onload = ( event ) => resolve( event.target.result );
        reader.onerror = reject;
    } );
}


onDragOver( banner ) {
    banner.classList.add( 'dragover' );
    return false;
}

Webstorm's code inspection suggest me that Method can be static for the onDragOver method. My question is:

Are there any real benefit from having the method as static or this suggestion is somehow useless?

Answer 1

Yes, you don't need an instance of the object when invoking a static function. All you need is a reference to the constructor:

class Foo {
  static bar() { console.log("foo"); }
}

Foo.bar(); // outputs "foo" to console

No need for a new Foo() anywhere.

By convention, instance methods should be used when you actually need state (either to read state, or to write state) from an instance.

The inspection will tell you that when you have a prototype/class method that does not have a this in it (and thus doesn't need an instance).