Fails when passing arguments to call back function used in "then" promise

[willemneal]

Describe the bug

Using promise.then fails when arguments are being passed to the callback function.
The logs confirm that the args are encoded correctly.

export function reverseWordThree(): void {
  const word = new Word("sample")
  const contract = "words.examples"
  const method = "reverse"

  // setup args object for cross-contract call as key-value of contract method parameters
  // note: the method signature in the words contract is reverse(word: Word)
  let reverseArgs = new ReverseArgs(word)

  let promise = ContractPromise.create(
    contract,                             // contract account name
    method,                               // contract method name
    reverseArgs.encode(),                 // serialized contract method arguments encoded as Uint8Array
    10000000,                                    // gas attached to the call
    u128.Zero                             // attached deposit to be sent with the call
  )

  // Setting up args for the callback
  let responseArgs = new ReverseArgs(new Word("elpmas"));
  logging.log(responseArgs); // <-- this encodes it to print it.

  logging.log(context.contractName)

  let callbackPromise = promise.then(
    context.contractName,
    "_onReverseCalledTwo",
    responseArgs.encode(), //<- Passing empty byte array works for function that doesn't expect args
    2
  );

  callbackPromise.returnAsResult();
}

export function _onReverseCalledTwo(word: Word): bool {
  const drow = word;
  let results = ContractPromise.getResults();
  assert(results.length > 0, "should be contract promise result");
  let reverseResult = results[0];
  // logging.log(results[0]);
  // Verifying the remote contract call succeeded.
  if (reverseResult.status == 1) {
    // Decoding data from the bytes buffer into the local object.
    let word = decode<Word>(reverseResult.buffer);
    logging.log(word);
    return word.text == drow.text
  }

  return false
}

To Reproduce
See https://gitpod.io/#https://github.com/near/near-sdk-as/tree/cross_contract_bug

It should fail on start, but to rerun yarn test:vm, or in the vm directory, yarn ts-node test.ts

The test is vm/test.ts and the corresponding AS file is assembly/__tests__/sentences.ts

Expected behavior
Not fail when passing input args to then

Screenshots

Version (please complete the following information):

• nearcore commit/branch
• rust version (if local)
• docker (if using docker)
• mainnet/testnet/betanet/devnet/local

Additional context
Add any other context about the problem here.

[willemneal]

Fixed! Issue was AS specific.