Helper objects for generating ERC20s while testing a Brownie project.

• python3 version 3.6 or greater, python3-dev
• brownie version 1.11.6 or greater
• ganache-cli version 6.11.0 or greater

If you have installed Brownie using pipx, you need to add brownie-token-tester into the same virtual environment:

pipx inject eth-brownie brownie-token-tester

You can install the latest release via pip:

pip install brownie-token-tester

You can clone the repository and use setuptools for the most up-to-date version:

git clone https://github.com/iamdefinitelyahuman/brownie-token-tester.git
cd brownie-token-tester
python3 setup.py install

Import the library from within a Brownie test, script or console:

from brownie_tokens import ERC20, MintableForkToken

You can then make use of the following functionality:

Deploys a generic ERC20 contract for testing purposes.

def ERC20(
    name: str = "Test Token",
    symbol: str = "TST",
    decimals: int = 18,
    success: Union[bool, None] = True,
    fail: Union[bool, str, None] = "revert",
) -> Contract:

• The success kwarg is used to set the token's return value upon a successful call to approve, transfer or transferFrom. Valid values are True, False, and None.
• The fail kwarg sets the token's behaviour upon failed calls to the above methods. Use "revert" if the transaction should revert, or True, False, and None to return a value without reverting.

The resulting deployment adheres to the ERC20 Token Standard and additionally implements one non-standard method:

def _mint_for_testing(target: address, amount: uint256): nonpayable

This method increases the balance of target by amount. It may be called by any account.

MintableForkToken is used to standardize the process of minting tokens when working in a forked mainnet environment. The MintableForkToken class inherits from and may be used interchangeably with the Contract class. It exposes one additional method, _mint_for_testing, with the same API as given above.

For tokens where custom logic is implemented, this is an actual minting event. For most tokens, the "minting" process involves a query to the Ethplorer API to get a list of top token holders, and then transferring their balances to target. If you want to exclude some holders from this process use skip_holders(*addresses). If you have too many requests at a time set $ETHPLORER_API_KEY(see ethplorer.io) as environment variable.

Tokens for which custom logic is currently implemented:

• Aave tokens
• DAI
• EURS
• LinkUSD
• pBTC
• Synthetix synths
• renBTC
• renZEC
• rETH
• RSV
• USDC
• USDN
• USDT
• tBTC
• wBTC
• wZEC

This project is still in early development and should be considered an alpha. Comments, questions, criticisms and pull requests are welcomed.

This project is licensed under the MIT license.