Examples: query, "exact match", wildcard*, wild?ard, wild*rd
Fuzzy search: cake~ (finds cakes, bake)
Term boost: "red velvet"^4, chocolate^2
Field grouping: tags:(+work -"fun-stuff")
Escape special characters +-&|!(){}[]^"~*?:\ - e.g. \+ \* \!
Range search: properties.timestamp:[1587729413488 TO *] (inclusive), properties.title:{A TO Z}(excluding A and Z)
Combinations: chocolate AND vanilla, chocolate OR vanilla, (chocolate OR vanilla) NOT "vanilla pudding"
Field search: properties.title:"The Title" AND text
How can you debug a TON smart contract in FunC and print logs or dump variables?

I'm developing a smart contract for TON blockchain in FunC and I'm trying to find a bug in my code. I'm trying to debug the issue and will appreciate something like console.log() from JavaScript so I can add prints / logs in strategic places and understand what's going on. Can this be done?

Posted 8 months ago
Tal Kol
285 × 3 Administrator
Votes Newest


The TVM has a special function for dumping variables in debug - ~dump

Run ~dump(variable_name); to print a variable's contents.

Run ~dump(12345); to print the number 12345.


() recv_internal(int msg_value, cell in_msg, slice in_msg_body) impure {

  ;; let's say I want to print the value of the variable msg_value

Please note that this command will not run on mainnet, so do not deploy production contracts with it. My favorite way to test smart contracts locally is using ton-contract-executor - this awesome library run a local version of the TVM in web-assembly right inside Node.js, which is very convenient for writing JavaScript/TypeScript tests.

To enable debug prints in ton-contract-executor, when you create your contract instance pass debug: true in SmartContractConfig and print the logs after interacting with the contract:

import { SmartContract } from "ton-contract-executor";

const contract = await SmartContract.fromCell(codeCell, dataCell, {
  debug: true // enable debug

const send = await contract.sendInternalMessage(...);

console.log(send.logs); // print the logs
Posted 8 months ago
Edited 8 months ago
Tal Kol
285 × 3 Administrator