function test_wp_prepare_attachment_for_js_without_image_sizes() {
    // Create the attachement post.
    $id = wp_insert_attachment(
      array(
        'post_title'     => 'Attachment Title',
        'post_type'      => 'attachment',
        'post_parent'    => 0,
        'post_mime_type' => 'image/jpeg',
        'guid'           => 'http://' . WP_TESTS_DOMAIN . '/wp-content/uploads/test-image.jpg',
      )
    );

    // Add attachment metadata without sizes.
    wp_update_attachment_metadata(
      $id,
      array(
        'width'  => 50,
        'height' => 50,
        'file'   => 'test-image.jpg',
      )
    );

    $prepped = wp_prepare_attachment_for_js( get_post( $id ) );

    $this->assertTrue( isset( $prepped['sizes'] ) );
  }