GoogleSheet Formula BASE64 Encoding/Decoding

/**
  * A custom function that encodes or decodes base64.
  *
  *@param {"R29vZ2xl"} data The string to encode/decode.
  *@param {1} encode 1/true = encode (default).0/false = decode.
  *@param {1} charsetStr The character set to use. Allowed values are "UTF-8" and "US-ASCII". Defaults to UTF-8.
  *@param {0} websafe Whether the output string should be safe for use in URLs or not. Defaults to false.
  *@param {0} asString Whether the decoded value should be returned as a string (default) or byte array.
  *@result {"Google"} The result to be returned.
  *@customfunction
  */
function BASE64EITHER(data,encode,charsetStr,websafe,asString) {
  if(data==="" || data==null){return ""}
  if(encode==="" || encode==null){encode=1}
  else if(encode != 1 && encode!=0 && encode!= true && encode!= false){return "Encode?";}
  if(encode==true){encode=1;}
  else if(encode==false){encode=0;}
  if(charsetStr==="" || charsetStr==null){charsetStr="UTF-8"}
  else if(charsetStr!="UTF-8" && charsetStr!="US-ASCII"){return "Charset?"}
  if(charsetStr=="UTF-8" || charsetStr==1){var charset = Utilities.Charset.UTF_8;}
  else{var charset = Utilities.Charset.US_ASCII;}
  if(websafe==="" ||websafe==null){websafe=0}
  else if(websafe != 1 && websafe!=0 && websafe!= true && websafe!= false){return "Websafe?";}
  else if(websafe==true){websafe=1;}
  else if(websafe==false){websafe=0}
  if(asString==="" ||asString==null){asString=1}
  else if(asString != 1 && asString!=0 && asString!= true && asString!= false){return "AsString?";}
  else if(asString==true){asString=1;}
  else if(asString==false){asString=0}
  var value;
  if(encode==0){
    if(websafe==0){
      if(asString==0){
        value= Utilities.base64Decode(data, charset);
      }else{
        value= Utilities.newBlob(Utilities.base64Decode(data, charset)).getDataAsString(charsetStr);
      }
    }else{
      if(asString==0){
        value= Utilities.base64DecodeWebSafe(data, charset);
      }else{
        value= Utilities.newBlob(Utilities.base64Decode(data, charset)).getDataAsString(charsetStr);
      }
    }
  }
  else{
      if(websafe==0){
        value= Utilities.base64Encode(data, charset);
    }
    else{value= Utilities.base64EncodeWebSafe(data, charset);}
  }
  return value;
}

/**
  * A custom function that ENcodes into base64 by forwarding the call to the BASE64 function.
  *
  *@param {"{"residentUserId"=14,"dob":"2020/01/01-12:34:56 CST"}"} data The string to encode.
  *Defaults to 1/true = encode
  *Defaults to UTF-8.
  *Defaults to false.
  *@result {"eyJyZXNpZGVudFVzZXJJZCI9MTQsImRvYiI6IjIwMjAvMDEvMDEtMTI6MzQ6NTYgQ1NUIn0="} The result to be returned.
  *@customfunction
  */
function BASE64ENCODE(data) {
  return BASE64EITHER(data, 1)
}

/**
  * A custom function that DEcodes from base64 by forwarding the call to the BASE64 function.
  *
  *@param {"eyJyZXNpZGVudFVzZXJJZCI9MTQsImRvYiI6IjIwMjAvMDEvMDEtMTI6MzQ6NTYgQ1NUIn0="} data The string to decode.
  *Defaults to 0/false = decode
  *Defaults to UTF-8.
  *Defaults to false.
  *@result {"{"residentUserId"=14,"dob":"2020/01/01-12:34:56 CST"}"} The result to be returned.
  *@customfunction
  */
function BASE64DECODE(data) {
  return BASE64EITHER(data, 0)
}