createIdGenerator = template => {
  /**
   * ID generator
   *
   * @param {string} name         Relative file path
   * @returns {string}            Shape ID
   */
  const generator = function(name) {
    const pathname = this.separator ? name.split(path.sep).join(this.separator) : name;
    return format(template || '%s', path.basename(pathname.replaceAll(/\s+/g, this.whitespace), '.svg'));
  };

  return generator;
}
Default callback for shape ID generation

@param {string} template         Template string
@returns {string}                Shape ID