Forking

Creating a copy of the mainnet to be used within our internal environment

  • use dummy acc

  • but do not deploy mocks

  • add env variable: FORKED_BLOCKCHAIN_ENV

Create mainnet-fork-dev, add to brownie networks

  1. add fork network to brownie [call it mainnet-fork-dev]

  2. add it to development category

  3. brownie networks add development mainnet-fork-dev cmd=ganache-cli host=http:// 127.0.0.1 fork='https://mainnet.infura.io/v3/$WEB3_INFURA_PROJECT_ID' accounts=10 mnemonic=brownie port=8545

  • the single quotes in the fork link -> run as is

  • without single quotes: our env variable would be actualized into the URL

Infura forking typically has issues, so alchemy is suggested:

brownie networks add development mainnet-fork-dev cmd=ganache-cli host=http://127.0.0.1 fork=https://eth-mainnet.alchemyapi.io/v2/j13raIIaPyTnV9ZVv2UnQm48PUFcPDkL accounts=10 mnemonic=brownie port=8545

** mainnet-fork-dev is a development env. it wont have anything in deployment. cannot interact with existing contracts.

Note: brownie comes with mainnet-fork, no idea what the setup is. PatrickACollins: he deletes and use mainnet-fork-dev as default.

Run testing

brownie test --network mainnet-fork-dev

import pytest
from brownie import FundMe, accounts, network, exceptions
from multiprocessing.connection import wait
from scripts.fund_and_withdraw import fund 
from scripts.helpful_scripts import *
from scripts.deploy import deploy_fund_me

def test_fund_withdraw(): 
    account = get_account() 
    fund_me = deploy_fund_me() 
    print(f"THIS WORKS {fund_me.address}") 
    
    entrance_fee = fund_me.getEntranceFee() + 100 
    tx = fund_me.fund({"from": account, "value": entrance_fee}) 
    tx.wait(1) print(entrance_fee) 
    assert fund_me.addressToAmountFunded(account.address) == entrance_fee 
    
    tx2 = fund_me.withdraw({"from": account}) 
    tx2.wait(1) 
    assert fund_me.addressToAmountFunded(account.address) == 0
  • use our own dummy accounts

  • deploy new instances of our contracts (fork is dev).

  • ensure ganacheUI isn't running, else we cannot reference the cloned mainnet contracts

can take awhile for the forked node to respond. cos its coming from alchemy API. wait till you get response.

-- also, if you have ganache running, close it.

-- for some reason brownie attaches to it instead of pulling data from the fork host API.

-- test then fails, cos' there are no deployed contracts to pull price.

Git stuff

git init -b main (init branch called main) git config user.name "" git config user.email "calnix.289@gmail.com"

::push :: git add . _> cache files to staging area git status -> shows files in staging to be pushed

git commit -m 'first commit' git remote add origin git push -u origin main

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