test_fund_me.py returns AttributeError: 'NoneType' object has no attribute 'getEntranceFee'

[klovertexarkana]

I keep getting the above error. Prior to that testing returns:

The active network is development
Deploying Mocks...
Mocks deployed!
Contract deployed to 0x602C71e4DAC47a042Ee7f46E0aee17F94A3bA0B6

So it appear that my deploy script is working fine and I haven't had any issues deploying to development, ganache-local, or Goerli.

Here is test_fund_me.py:

from scripts.helpful_scripts import get_account
from scripts.deploy import deploy_fund_me


def test_can_fund_and_withdraw():
    account = get_account()
    fund_me = deploy_fund_me()
    entrance_fee = fund_me.getEntranceFee()

    tx = fund_me.fund({'from': account, 'value': entrance_fee})
    tx.wait(1)
    assert fund_me.addressToAmountFunded(account.address) == entrance_fee

    tx2 = fund_me.withdraw({'from': account})
    tx2.wait(1)
    assert fund_me.addressToAmountFunded(account.address) == 0

Here is my deploy.py:

from brownie import network, FundMe, MockV3Aggregator, config
from scripts.helpful_scripts import get_account, deploy_mocks, LOCAL_BLOCKCHAIN_ENVIRONMENTS


def deploy_fund_me():
    account = get_account()
    # need to pass appropriate price feed address to the .deploy() method
    if network.show_active() not in LOCAL_BLOCKCHAIN_ENVIRONMENTS:
        price_feed_address = config['networks'][network.show_active()]['eth_usd_price_feed']
    else:
        deploy_mocks()
        price_feed_address = MockV3Aggregator[-1].address


    fund_me = FundMe.deploy(price_feed_address, {'from': account},
                            publish_source=config['networks'][network.show_active()].get('verify'))
    print(f'Contract deployed to {fund_me.address}')


def main():
    deploy_fund_me()

[cromewar]

Hello @klovertexarkana this might happen to several reasons.

1. you should wait one block confirmation before calling the getEntranceFee to ensure the contract was deployed.
2. Check you contract, does the function is called exactly getEntranceFee? may be there is a typo causing the problem.
3. You might have a bad contract cache, so delete the build folder on your project and try again.

I hope any of this info might help.

[klovertexarkana]

Due to the fact that this is returned: "AttributeError: 'NoneType' object has no attribute 'getEntranceFee'", but I get the print out that my contract was deployed successfully, I can't help but think that the contract gets deployed correctly and that for some reason brownie's test command is having a problem connecting to it. Hence, 'NoneType' object. Brownie is not able to utilize the getEntranceFee method because it has not contract to find the getEntranceFee method.

1. you should wait one block confirmation before calling the getEntranceFee to ensure the contract was deployed.

I tried the below to see if it would work and it did not:

from scripts.helpful_scripts import get_account
from scripts.deploy import deploy_fund_me


def test_can_fund_and_withdraw():
    account = get_account()
    fund_me = deploy_fund_me()
    fund_me.wait(1)
    entrance_fee = fund_me.getEntranceFee()

    tx = fund_me.fund({'from': account, 'value': entrance_fee})
    tx.wait(1)
    assert fund_me.addressToAmountFunded(account.address) == entrance_fee

    tx2 = fund_me.withdraw({'from': account})
    tx2.wait(1)
    assert fund_me.addressToAmountFunded(account.address) == 0

2. Check you contract, does the function is called exactly getEntranceFee? may be there is a typo causing the problem.

Here is my getEntranceFee() from FundMe.sol:

function getEntranceFee() public view returns (uint256) {
    // minimumUSD
    uint256 minimumUSD = 50 * 10**18;
    uint256 price = getPrice();
    uint256 precision = 1 * 10**18;
    return (minimumUSD * precision) / price;

3. You might have a bad contract cache, so delete the build folder on your project and try again.

I deleted my build folder, re-compiled and deployed to 'ganache-local' and Goerlie and there was not problem at all. Testing still produced the same error output.

[cromewar]

Ok I found your problem on the deploy script deploy_fund_me you must return fund_me at the end, otherwise when you go fund_me = deploy_fund_me() it will be empty. Check it out the code repo: https://github.com/PatrickAlphaC/brownie_fund_me/blob/main/scripts/deploy.py

[klovertexarkana]

Wow, well that certainly makes sense! And yes it now works fine. Thank you!

[cromewar]

I'm glad is solved now.