03-from-consensus-buff-empty.js

// SIP-039: from-consensus-buff? with empty buffer no longer errors (issue #6683)
// Deploys a contract that calls from-consensus-buff? with an empty buffer.
// Before epoch 3.4 this would trigger a runtime cost error.
// Now it should return none.

const {
  makeContractDeploy,
  ClarityVersion,
  PostConditionMode,
  getAddressFromPrivateKey,
} = require("@stacks/transactions");
const { STACKS_TESTNET } = require("@stacks/network");
const { PRIVATE_KEY, NETWORK, API_URL } = require("./config");
const { broadcast } = require("./broadcast");

const codeBody = `
;; This should return none instead of erroring
(define-read-only (test-empty-buff)
  (from-consensus-buff? uint 0x)
)

;; Sanity check: valid consensus buffer for a uint
(define-read-only (test-valid-buff)
  (from-consensus-buff? uint 0x0000000000000000000000000000002a)
)
`;

async function main() {
  const tx = await makeContractDeploy({
    codeBody,
    contractName: "consensus-buff-empty-test",
    clarityVersion: ClarityVersion.Clarity5,
    senderKey: PRIVATE_KEY,
    network: NETWORK,
    fee: 50000,
    postConditionMode: PostConditionMode.Deny,
  });
  const result = await broadcast(tx, "SIP-039: from-consensus-buff? with empty buffer");
  if (!result.ok) return;

  // Call the read-only functions to verify behavior
  const senderAddress = getAddressFromPrivateKey(PRIVATE_KEY, STACKS_TESTNET);
  const contractId = `${senderAddress}.consensus-buff-empty-test`;

  for (const fn of ["test-empty-buff", "test-valid-buff"]) {
    const res = await fetch(
      `${API_URL}/v2/contracts/call-read/${contractId}/${fn}`,
      {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({ sender: senderAddress, arguments: [] }),
      }
    );
    const data = await res.json();
    console.log(`\n  ${fn}: ${data.result}`);
  }
}

main().catch(console.error);