Calls (.name() and .symbol()) to ERC20/ERC721 contracts return not human-readable strings.

[mckrava]

Ethers Version

5.6.9

Search Terms

decode string, decode contract call result

Describe the Problem

Hi!
I have problem with some contracts in Moonbeam network in some blocks range (in earlier blocks issue can occur but later not). For instance:

blockHeight -  171962
contractAddress -  0x8e70cd5b4ff3f62659049e74b6649c6603a0e594
name() ->  0006648936.1ec7 (typeof === 'string')
symbol() ->  0006648936.1ec7 (typeof === 'string')

But later (sort of after 400000) this contract returns name() -> Tether USD. Probably it's a problem with specific contracts but I'm trying figure out how to decode this weird string value (0006648936.1ec7) and is there some function in ethers which can help me with this.

Code Snippet

const wsProvider = new ethers.providers.WebSocketProvider('wss://wss.api.moonbeam.network');
const contractInst = new ethers.Contract('0x8e70cd5b4ff3f62659049e74b6649c6603a0e594', erc20ContractAbi, wsProvider); // "erc20ContractAbi" it's default ERC20 contract ABI

const contractName = await contractInst.name({blockTag: 171962}); // -> 0006648936.1ec7
const contractName = await contractInst.name(); // -> Tether USD

Contract ABI

[
  {
    "constant": true,
    "inputs": [],
    "name": "name",
    "outputs": [
      {
        "name": "",
        "type": "string"
      }
    ],
    "payable": false,
    "stateMutability": "view",
    "type": "function"
  },
  {
    "constant": false,
    "inputs": [
      {
        "name": "_spender",
        "type": "address"
      },
      {
        "name": "_value",
        "type": "uint256"
      }
    ],
    "name": "approve",
    "outputs": [
      {
        "name": "",
        "type": "bool"
      }
    ],
    "payable": false,
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "constant": true,
    "inputs": [],
    "name": "totalSupply",
    "outputs": [
      {
        "name": "",
        "type": "uint256"
      }
    ],
    "payable": false,
    "stateMutability": "view",
    "type": "function"
  },
  {
    "constant": false,
    "inputs": [
      {
        "name": "_from",
        "type": "address"
      },
      {
        "name": "_to",
        "type": "address"
      },
      {
        "name": "_value",
        "type": "uint256"
      }
    ],
    "name": "transferFrom",
    "outputs": [
      {
        "name": "",
        "type": "bool"
      }
    ],
    "payable": false,
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "constant": true,
    "inputs": [],
    "name": "decimals",
    "outputs": [
      {
        "name": "",
        "type": "uint8"
      }
    ],
    "payable": false,
    "stateMutability": "view",
    "type": "function"
  },
  {
    "constant": true,
    "inputs": [
      {
        "name": "_owner",
        "type": "address"
      }
    ],
    "name": "balanceOf",
    "outputs": [
      {
        "name": "balance",
        "type": "uint256"
      }
    ],
    "payable": false,
    "stateMutability": "view",
    "type": "function"
  },
  {
    "constant": true,
    "inputs": [],
    "name": "symbol",
    "outputs": [
      {
        "name": "",
        "type": "string"
      }
    ],
    "payable": false,
    "stateMutability": "view",
    "type": "function"
  },
  {
    "constant": false,
    "inputs": [
      {
        "name": "_to",
        "type": "address"
      },
      {
        "name": "_value",
        "type": "uint256"
      }
    ],
    "name": "transfer",
    "outputs": [
      {
        "name": "",
        "type": "bool"
      }
    ],
    "payable": false,
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "constant": true,
    "inputs": [
      {
        "name": "_owner",
        "type": "address"
      },
      {
        "name": "_spender",
        "type": "address"
      }
    ],
    "name": "allowance",
    "outputs": [
      {
        "name": "",
        "type": "uint256"
      }
    ],
    "payable": false,
    "stateMutability": "view",
    "type": "function"
  },
  {
    "payable": true,
    "stateMutability": "payable",
    "type": "fallback"
  },
  {
    "anonymous": false,
    "inputs": [
      {
        "indexed": true,
        "name": "owner",
        "type": "address"
      },
      {
        "indexed": true,
        "name": "spender",
        "type": "address"
      },
      {
        "indexed": false,
        "name": "value",
        "type": "uint256"
      }
    ],
    "name": "Approval",
    "type": "event"
  },
  {
    "anonymous": false,
    "inputs": [
      {
        "indexed": true,
        "name": "from",
        "type": "address"
      },
      {
        "indexed": true,
        "name": "to",
        "type": "address"
      },
      {
        "indexed": false,
        "name": "value",
        "type": "uint256"
      }
    ],
    "name": "Transfer",
    "type": "event"
  }
]

Errors

No response

Environment

node.js (v12 or newer)

Environment (Other)

No response

[zemse]

// eth_call resp for contract.name()
{
    "jsonrpc": "2.0",
    "result": "0x0000000000000000000000000000000000000000000000000000000000000020000000000000000000000000000000000000000000000000000000000000000f303030363634383933362e316563370000000000000000000000000000000000",
    "id": 44
}
// which decodes to "0006648936.1ec7" as mentioned in OP

I don't think this is an issue with ethers.js as, the response from node is in that way. You can reach out to Moonbeam support or Tether support regarding this.

Some info:

• Block 172217 gives "Tether USD" while 172216 gives the other value.
• The contract is upgradable, so I think Tether might have upgraded the implementation in block 172217 to reflect the correct value. Though I was not easily able to find any transaction related to that on their block explorer.