Formatting zip code to remove characters, spaces and trim to 5 digits

zip_code_formatter.js

exports.main = async (event, callback) => {
  const zip  = event.inputFields['zip'];  
  // REMOVE ANY EMPTY SPACES FROM THE ZIP CODE
  let no_spaces_zip = zip.replace(/\s/g, '');
  // REMOVE ANY NON-NUMERICAL CHARACTERS
  let no_character_zip = no_spaces_zip.replace(/\D/g,'');  
  // MEASURE THE LENGTH OF THE ZIP CODE
  let zip_length = no_character_zip.length;  
  
  // IF THE ZIP CODE IS 5 CHARACTERS
  if (zip_length == 5) {
    let better_zip = no_character_zip;  
    callback({
      outputFields: {
        new_zip: better_zip
      } 
    });
  // CLEAR THE ZIP VALUE IF IT IS LESS THAN 5 CHARACTERS
  } else if (zip_length < 5) {
    let better_zip = '-'; 
    callback({
      outputFields: {
        new_zip: better_zip
      } 
    });
  // IF THE ZIP IS BIGGER THAN 5 CHARACTERS SUBSTRING
  } else {
	// NOTE THAT THIS WOULD CHANGE ANY ZIP +4 VALUES TO ONLY 5 DIGIT ZIP
    // ADD CONDITIONS HERE TO ADDRESS ZIP +4 IF YOU WANT TO KEEP
    let better_zip = no_character_zip.substring(0,5); 
    callback({
      outputFields: {
        new_zip: better_zip
      } 
    });
  }
}