Hardhat issue UNPREDICTABLE_GAS_LIMIT in a script within ethereum development of ERC-721

Question

I have a problem that I really despair of and I think it has maybe to do with an "wait for confirmation?" issue, but I don't know how to activate this.

Issue is, that I get as result of an request against a function of my ERC-721 contract following message in a deployment script :

reason: 'cannot estimate gas; transaction may fail or may require manual gas limit', code: 'UNPREDICTABLE_GAS_LIMIT',

I think it maybe has to do with that the commands are happening to fast after each other because, when I proceed the following steps in a hardhad console manually (npx hardhat console -.network rinkeby), everthing works without this error (even with that <>.confirmations are always 0, what I don't understand)

I have the following commands in a deploy.js I run with:

npx hardhat run -.network rinkeby scripts/deploy.js

async function main() {
    const BBA = await hre.ethers.getContractFactory("mycontract");
    const bba = await BBA.deploy();
    await bba.deployed();
    console.log("mycontract deployed to:", bba.address);

    await bba.safeMint("0x123...", 0, 'https://gateway.pinata.cloud/ipfs/url');

    await bba.lockToken(0, "1644598343");

    console.log(await bba.getLock(0));
    ...
}

With the call await bba.getLock(0) I get the Error: cannot estimate gas; transaction may fail or may require manual gas limit (error={"name":"ProviderError","code":-32000,"_isProviderError":true}, method="call", transaction=...

I build a 1:1 ERC-721 based on openzeppelin contract wizard https://docs.openzeppelin.com/contracts/4.x/wizard .

In this contract I added a simple function:

    mapping(uint256 => uint256) private _locks;

    function lockToken(
        uint256 targetTokenId,
        uint256 since,
    ) public {
        _locks[targetTokenId] = since;
    }
    
   function getLock(uint256 targetTokenId) public view returns (uint256) {
        return _locks[targetTokenId];
    }

I use INFURA with following hardhat.config.js:

const { projectId, mnemonic } = require('./secrets.json');

module.exports = {
    rinkeby: {
      url: "https://rinkeby.infura.io/v3/" + projectId,
      accounts: { mnemonic: mnemonic },
      confirmations: 2,
      gas: 2100000,
      gasPrice: 8000000000,
      saveDeployments: true
    }
  },
  solidity: {
    version: "0.8.4",
    settings: {
      evmVersion: "byzantium",
      optimizer: {
        enabled: true,
        runs: 1500,
      }
    }
  }
};

Anyone could guide me, to the reason of that problem?

Thanks in advance.

Answer 1

after additional research and testing the solution seems very simple.

I just needed to declare a const for the function calls and then needed to call a wait() call on these.

As I read, then the procedure waits for the call to be mined.

I'm still unsure how I can command to wait for two confirmations, but at already fixes the GAS LIMIT issue.

const mint = await bba.safeMint("0x123...", 0, 'https://gateway.pinata.cloud/ipfs/url');

await mint.wait();

const locking= await bba.lockToken(0, "1644598343");

await locking.wait();

console.log(await bba.getLock(0));