Send ether to contract address in web3.js

Question

I want to send ether to this contract's contribute function using web3.js

I'm trying below code for the same but this doesn't work for me.

var AbiOfContract = 'abi_code';
var contractAddress = "0x8bbc*************************";
var contract1 = web3.eth.contract(JSON.parse(AbiOfContract)).at(contractAddress);

contract1.contribute({"to": contractAddress ,"from": accounts[1], "value": web3.toWei("10.0", "ether")},"password");

contract CrowdFunder {

    function contribute()
    public
    inState(State.Fundraising) payable returns (uint256)
    {
        contributions.push(
            Contribution({
                amount: msg.value,
                contributor: msg.sender
                })
            );
        totalRaised += msg.value;
        currentBalance = totalRaised;
        LogFundingReceived(msg.sender, msg.value, totalRaised);
        checkIfFundingCompleteOrExpired();
        return contributions.length - 1;
    }
}

Any help regarding this will be highly appreciated.

Answer 1

If you want to accept the Ether in a smart contract then you should have a fallback function. The fallback function will be called by default when someone transfers ETH to the contract address.

contract Crowdfunder{
   function() Crowdfunder { }
   function() payable {
      contributions.push(
        Contribution({
            amount: msg.value,
            contributor: msg.sender
            })
        );
    totalRaised += msg.value;
    currentBalance = totalRaised;
    LogFundingReceived(msg.sender, msg.value, totalRaised);
    checkIfFundingCompleteOrExpired();
  }
}

In web3js you can send through the normal transaction.

let send = web3.eth.sendTransaction({from:eth.coinbase,to:contract_address, value:web3.toWei(0.05, "ether")});

For further reference regarding fallback function check here.

Answer 2

At the time of writing, funding a contract is best done with the receive function.

contract CrowdFunder {
  receive () external payable {
    // what to do when receiving funds...
  }
}

You can then trigger the receive function by sending ether directly to the contract address.

web3.eth.sendTransaction({
  from: senderAddress,
  to: contractAddress,
  value: web3.utils.toWei('1', 'ether'),
});

It was previously possible to do so with the fallback function, which now has a limit of 2300 gas to perform operations (the receive function does not have a gas limit).

Answer 3

I was trying to write a test suite in Truffle where I initially fund my smart contract in order to operate certain operations.

Inside my Test script, I had something like this:

it("Funds the Smart Contract With Test Ether", async () => {
  const addressContract = await TriviaContract.address
  await web3.eth.sendTransaction({
    from: accounts[9],
    to: String(addressContract),
    value: String(await web3.utils.toWei("1", "ether"))
  });
  const ContractBalance = await web3.utils.fromWei(await web3.eth.getBalance(TriviaContract.address))
  console.log(ContractBalance);
})

Whenever I will run my test script, I would get an error that looks like this:

My transaction was reverting because I did not enable my Smart Contract to receive Ethers. All I had to do was add a special receive() function inside my smart contract and everything worked after that:

receive () external payable {
    // Do whatever you want when receiving funds...
  }

I hope this helps anyone out there who was experiencing the same issue.

Cheers.