To ensure compatibility, follow these guidelines when uploading a custom JavaScript decoder. The decoder function should be denoted as `Decoder(bytes, port)`.

Here's a simple example of a custom JavaScript decoder function conforming to the required function signature:

/**
* Custom decoder function for decoding data.
* @param bytes - The payload data to be decoded (an array of bytes).
* @param port - The port number used during decoding.
* @returns {string} - The decoded result as a string.
*/
function Decoder(bytes, port) {
  // Your decoding logic here
  let decodedResult = {}; //empty object that holds all UDT tag values
  decodedResult.Measurement = bytes[1]
  decodedResult.BatteryLevel = bytes[2]
  decodedResult.Temperature = bytes[3]
  return decodedResult;
}

• Function Signature: The decoder function must have the following signature: function Decoder(bytes, port) { Your decoding logic here }
  • Other functions can be used in the file can called from the Decoder function, but the Decoder(…) function acts as the main function.

• GraalVM Support: Ensure that the JavaScript code used in the decoder is compatible with GraalVM's JavaScript engine. GraalVM supports most ECMAScript 5.1 features and some ECMAScript 2015 (ES6) features. Refer to GraalVM's documentation for the specific version details and supported features.

* bytes: This parameter represents the input data that needs to be decoded. It is an array of bytes that is gathered from an uplink's payload.

* port: This parameter denotes the port number that might be used within the decoder function or during the decoding process.

- Dependency Management: Ensure that any external dependencies used in your JavaScript code are compatible with GraalVM. Double-check that any libraries or modules you include are compatible with the JavaScript engine in GraalVM.

- Runtime Limitations: Be aware of the runtime limitations and constraints of GraalVM. For example, certain features or APIs available in other JavaScript engines may not be present in GraalVM. Refer to the GraalVM documentation for any restrictions you should consider while writing your custom decoder.

- Testing: Before uploading the custom JavaScript decoder, thoroughly test it in a GraalVM environment. Ensure that it performs as expected and adheres to the function signature mentioned above.