Web3js – How to Fix web3.toWei Is Not a Function Error in Testing

There are several possible explanations. It's not possible to be certain because the rest of the contract isn't posted.

1. Possible the contract didn't compile and/or deploy successfully. Be certain there is a valid contract at the address you're sending the transaction.
2. Possible the contract throws instead of successfully executing. For example, this line: if (crowdsaleClosed) throw;. If that is true, then there will be no event emitted.

The commented lines (below) could be suspect.

I'm not certain this is on point, but it might be helpful in this case. In most languages, one can record messages during debugging and the log will indicate things that happened before a crash. In Ethereum, if anything should cause the execution to throw then the state will revert to the pre-transaction state (with gas destroyed).

The effect of an error is that Ether is returned and no events are emitted, as if the transaction never happened. It may be helpful to think of transactions as either 100% successful or 100% failed. We don't get events to help understand failures. That would be a semi-successful transaction which is not allowed.

In practice, this means we can't add events to a problematic function to gain insight into what's going wrong. If something goes wrong at any stage, it means no event will be emitted regardless of the order of steps in the function. It also means we shouldn't assume failure happened early merely because event emission came first. The error might occur further on in processing, but since errors cancel events, we don't get a hint about the step that caused the error.

Below seems to work.

contract Fallback {

    event PayableCalled(bool called);
    bool crowdsaleClosed;

    function () payable {
        PayableCalled(true);   //event registered to ensure that function was called
        if (crowdsaleClosed) throw;
        uint amount = msg.value;
        // balanceOf[msg.sender] = amount; // consider +=
        // amountRaised += amount;
        // Transaction(msg.sender,msg.value,amountRaised);
        // tokenReward.transfer(msg.sender, amount / price);
        // FundTransfer(msg.sender, amount, true);
    }  
}

In Remix to show it working.

Hope it helps.

web3.eth.blockNumber is synchronous. You need to change this to web3.eth.getBlockNumber((err, res) => {})

Alternatively you can restructure this chain with promises:

const Promise = require('bluebird');
const Web3 = require('web3');
const web3 = new Web3(new Web3.providers.HttpProvider(<WEB3_PROVIDER_URL>));

if (typeof web3.eth.getAccountsPromise === 'undefined') {
  Promise.promisifyAll(web3.eth, { suffix: 'Promise' });
}

Then you can do:

web3.getBlockNumberPromise()
.then(_blockNumber => web3.eth.getBlock(_blockNumber))
.then(_block =>   { YOUR BLOCK CODE })