Uncaught Reference error in Retina.js

Question

I am trying to make my theme retina ready. i have included following code in my theme files. but it raise following

Uncaught reference Error: Exports is not defined 
.............js/retina.js?ver=4.6.1 line 12.

I am wondering why it is saying that the error is in script file. as i have downloaded script file again and again and i am pretty much sure that there is no error in the retina.js file. can any one help to sort out this? Following is my code:

<?php 
add_action( 'wp_enqueue_scripts', 'retina_support_enqueue_scripts' );
/**
 * Enqueueing retina.js
 *
 * This function is attached to the 'wp_enqueue_scripts' action hook.
 */
function retina_support_enqueue_scripts() {
    wp_enqueue_script( 'retina_js', get_template_directory_uri() . '/js/retina.js', '', '', true );
}
add_filter( 'wp_generate_attachment_metadata', 'retina_support_attachment_meta', 10, 2 );
/**
 * Retina images
 *
 * This function is attached to the 'wp_generate_attachment_metadata' filter hook.
 */
function retina_support_attachment_meta( $metadata, $attachment_id ) {
    foreach ( $metadata as $key => $value ) {
        if ( is_array( $value ) ) {
            foreach ( $value as $image => $attr ) {
                if ( is_array( $attr ) )
                    retina_support_create_images( get_attached_file( $attachment_id ), $attr['width'], $attr['height'], true );
            }
        }
    }

    return $metadata;
}

/**
 * Create retina-ready images
 *
 * Referenced via retina_support_attachment_meta().
 */
function retina_support_create_images( $file, $width, $height, $crop = false ) {
    if ( $width || $height ) {
        $resized_file = wp_get_image_editor( $file );
        if ( ! is_wp_error( $resized_file ) ) {
            $filename = $resized_file->generate_filename( $width . 'x' . $height . '@2x' );

            $resized_file->resize( $width * 2, $height * 2, $crop );
            $resized_file->save( $filename );

            $info = $resized_file->get_size();

            return array(
                'file' => wp_basename( $filename ),
                'width' => $info['width'],
                'height' => $info['height'],
            );
        }
    }
    return false;
}

add_filter( 'delete_attachment', 'delete_retina_support_images' );
/**
 * Delete retina-ready images
 *
 * This function is attached to the 'delete_attachment' filter hook.
 */
function delete_retina_support_images( $attachment_id ) {
    $meta = wp_get_attachment_metadata( $attachment_id );
    $upload_dir = wp_upload_dir();
    $path = pathinfo( $meta['file'] );
    foreach ( $meta as $key => $value ) {
        if ( 'sizes' === $key ) {
            foreach ( $value as $sizes => $size ) {
                $original_filename = $upload_dir['basedir'] . '/' . $path['dirname'] . '/' . $size['file'];
                $retina_filename = substr_replace( $original_filename, '@2x.', strrpos( $original_filename, '.' ), strlen( '.' ) );
                if ( file_exists( $retina_filename ) )
                    unlink( $retina_filename );
            }
        }
    }
}

Answer 1

It sounds like it might be an issue with the way the distributed version of the script is compiling. I found this issue reported on their Github repo that could be related.

Try using the minified version (retina.min.js) included in the download zip package. Remember to update your script enqueue path if you're using a file with a different name too.