endsWith = (str, suffix) -> str.indexOf(suffix, str.length - suffix.length) != -1 module.exports = (formFields) -> correctedFormFields = {} for fieldKey, fieldValue of formFields newKey = switch Array.isArray fieldValue when false then fieldKey when true if endsWith(fieldKey, "[]") fieldKey else fieldKey + "[]" correctedFormFields[newKey] = fieldValue return correctedFormFields