export function getFormData(form: HTMLFormElement) {
  const isValidElement = (element: HTMLFormElement) => {
    return element.name && element.value;
  };
  
  const isCheckbox = (element: HTMLInputElement) => element.type === 'checkbox';
  const isMultiSelect = (element: HTMLSelectElement) => element.options && element.multiple;
  
  const getSelectValues = (options: HTMLSelectElement) =>
    [].reduce.call(
      options,
      (values: string, option: HTMLOptionElement) => {
        return option.selected ? values.concat(option.value) : values;
      },
      []
    );
  
  const formToJSON = (elements: HTMLFormControlsCollection) =>
    [].reduce.call(
      elements,
      (data: any, element: any) => {
        if (isValidElement(element)) {
          if (isCheckbox(element)) {
            data[element.name] = element.checked;
          } else if (isMultiSelect(element)) {
            data[element.name] = getSelectValues(element);
          } else {
            data[element.name] = element.value;
          }
        }
        return data;
      },
      {}
    );
  const data = formToJSON(form.elements);
  return JSON.parse(JSON.stringify(data));
}