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Description:

pytestevm 0.2.0

pytest-evm

The testing package containing tools to test Web3-based projects

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Package's source code is made available under the MIT License
Quick Start
There are few features simplifying your testing with pytest:

Fixtures
Test Reporting
Usage Example

Fixtures
make_wallet
This fixture simplify creating wallet instances as fixtures. Wallet instances are from evm-wallet package
import os
import pytest
from typing import Optional
from evm_wallet.types import NetworkOrInfo
from evm_wallet import AsyncWallet, Wallet

@pytest.fixture(scope="session")
def make_wallet():
def _make_wallet(network: NetworkOrInfo, private_key: Optional[str] = None, is_async: bool = True):
if not private_key:
private_key = os.getenv('TEST_PRIVATE_KEY')
return AsyncWallet(private_key, network) if is_async else Wallet(private_key, network)

return _make_wallet

You can specify whether your wallet should be of async or sync version. Instead of specifying RPC, you only have to provide
chain's name. You can also specify a custom Network, using NetworkOrInfo.
import pytest

@pytest.fixture
def wallet(make_wallet):
return make_wallet('Optimism')

As you can see, a private key wasn't passed. This because of by-default make_wallet takes it from
environment variable TEST_PRIVATE_KEY. You can set environment variables using extra-package python-dotenv.
# conftest.py

import pytest
from dotenv import load_dotenv

load_dotenv()

@pytest.fixture(scope="session")
def wallet(make_wallet):
return make_wallet('Polygon')

Here is the content of .env file
# .env

TEST_PRIVATE_KEY=0x0000000000000000000000000000000000000000

You can install python-dotenv along with pytest-evm:
pip install pytest-evm[dotenv]

zero_address
This fixture returns ZERO_ADDRESS value
import pytest
from evm_wallet import ZERO_ADDRESS

@pytest.fixture(scope="session")
def zero_address():
return ZERO_ADDRESS

eth_amount
This fixture returns 0.001 ETH in Wei, which is the most using minimal value for tests
import pytest
from web3 import AsyncWeb3

@pytest.fixture(scope="session")
def eth_amount():
amount = AsyncWeb3.to_wei(0.001, 'ether')
return amount

Test Reporting
If your want to test one transaction, you can automatically assert transaction status and get useful report after test,
if it completed successfully. To do this, you need to add mark pytest.mark.tx to your test and you must return
transaction hash in test
import pytest

@pytest.mark.tx
@pytest.mark.asyncio
async def test_transaction(wallet, eth_amount):
recipient = '0xe977Fa8D8AE7D3D6e28c17A868EF04bD301c583f'
params = await wallet.build_transaction_params(eth_amount, recipient=recipient)
return await wallet.transact(params)

After test, you get similar report:

Usage Example
Here is example of testing with pytest-evm:
import pytest
from bridge import Bridge

class TestBridge:
@pytest.mark.tx
@pytest.mark.asyncio
async def test_swap(self, wallet, eth_amount, bridge, destination_network):
return await bridge.swap(eth_amount, destination_network)

@pytest.mark.tx
@pytest.mark.asyncio
async def test_swap_to_eth(self, wallet, eth_amount, bridge):
return await bridge.swap_to_eth(eth_amount)

@pytest.fixture
def wallet(self, make_wallet):
return make_wallet('Optimism')

@pytest.fixture
def bridge(self, wallet):
return Bridge(wallet)

@pytest.fixture
def destination_network(self):
return 'Arbitrum'

Installing pytest-evm
To install the package from GitHub you can use:
pip install git+https://github.com/blnkoff/pytest-evm.git

To install the package from PyPi you can use:
pip install pytest-evm