tests/test_lottery.py:14: AssertionError

[praxis-dev]

Hi!

I've encountered this error while performing test as stated at 6:29 moment of the course. There is something with the math - sums from assert functions appear to be one zero greater than it is needed. Any suggestions?

Here it is:

____________________________________________________________________ test_get_entrance_fee _____________________________________________________________________

    def test_get_entrance_fee():
        account = accounts[0]
        lottery = Lottery.deploy(
            config["networks"][network.show_active()]["eth_usd_price_feed"],
            {"from": account},
        )
    
>       assert lottery.getEntranceFee() > Web3.toWei(0.023, "ether")
E       AssertionError: assert 2544944580762219 > 23000000000000000
E        +  where 2544944580762219 = <ContractCall 'getEntranceFee()'>()
E        +    where <ContractCall 'getEntranceFee()'> = <Lottery Contract '0xE7eD6747FaC5360f88a2EFC03E00d25789F69291'>.getEntranceFee
E        +  and   23000000000000000 = <function to_wei at 0x7fb0ea211790>(0.023, 'ether')
E        +    where <function to_wei at 0x7fb0ea211790> = Web3.toWei

tests/test_lottery.py:14: AssertionError
=================================================================== short test summary info ====================================================================
FAILED tests/test_lottery.py::test_get_entrance_fee - AssertionError: assert 2544944580762219 > 23000000000000000
====================================================================== 1 failed in 12.66s =====================================================================

Here is the code:

lottery.sol

// SPDX-Licence-Identifier: MIT

pragma solidity ^0.6.6;

import "@chainlink/contracts/src/v0.6/interfaces/AggregatorV3Interface.sol";

contract Lottery {
    address payable[] public players;
    uint256 public usdEntryFee;
    AggregatorV3Interface internal ethUsdPriceFeed;

    constructor(address _priceFeedAddress) public {
        usdEntryFee = 50 * (10**18);
        ethUsdPriceFeed = AggregatorV3Interface(_priceFeedAddress);
    }

    function enter() public {
        // $50 minimum
        players.push(msg.sender);
    }

    function getEntranceFee() public view returns (uint256) {
        (, int256 price, , , ) = ethUsdPriceFeed.latestRoundData();
        uint256 adjustedPrice = uint256(price) * 10 * 10**10; //18 decimals
        uint256 costToEnter = (usdEntryFee * 10**18) / adjustedPrice;
        return costToEnter;
    }

    function startLottery() public {}

    function endLottery() public {}
}

test_lottery.py

from brownie import Lottery, accounts, config, network
from web3 import Web3


def test_get_entrance_fee():
    account = accounts[0]
    lottery = Lottery.deploy(
        config["networks"][network.show_active()]["eth_usd_price_feed"],
        {"from": account},
    )

    assert lottery.getEntranceFee() > Web3.toWei(0.023, "ether")
    assert lottery.getEntranceFee() < Web3.toWei(0.027, "ether")


def main():
    test_get_entrance_fee()

[praxis-dev]

uint256 adjustedPrice = uint256(price) * 10 * 10**10; //18 decimals

There was a typo in the code - an unnecessary * 10
Problem solved

[cromewar]

I'm glad you found the solution so quick ;)