Warning

Pytest-Ethereum is still under active development, and yet to reach a stable release. It should not be used in production yet.

Overview¶

This library is designed to make deploying and testing smart contracts simple, using Py-EthPM and pytest.

Vyper¶

This library automatically reveals a vy_deployer fixture available to compile and package your vyper contracts. The vy_deployer fixture will automatically compile all vyper contracts found in a subdirectory “contracts/” of the current working directory into a manifest according to the EthPM spec(link).

Solidity¶

This library automatically reveals a solc_deployer fixture available to package up a given solidity manifest, expose a Deployer instance. To create a manifest (link).

from ethpm import Package

@pytest.fixture
def owned_deployer(solc_deployer):
    owned_manifest_path = Path('to/owned/manifest.json')
    owned_deployer = solc_deployer(path=owned_manifest_path)
    return owned_deployer.deploy("Owned")

Deployer¶

A Deployer object is created to help create contract instances for any provided contracts.

To deploy any of the available contract types onto the default w3 instance, simply call deploy on the deployer and a newly created Package instance (which contains the newly created contract instance in its deployments) will be returned, along with the address of the newly deployed contract type.

from ethpm import Package
from eth_utils import is_same_address

@pytest.fixture
def owned_deployer(solc_deployer):
    owned_manifest_path = Path('to/owned/manifest.json')
    owned_deployer = solc_deployer(path=owned_manifest_path)
    return owned_deployer.deploy("Owned")

def test_owned_contract(owned_deployer)
    owned_package, owned_address = owned_deployer
    assert isinstance(owned_package, Package)
    owned_contract_instance = owned_deployer.deployments.get_deployment_instance("Owned")
    assert is_same_address(owned_contract_instance.address, owned_address)

Deployer.deploy(contract_type)¶: Deploys an instance of given contract_type if sufficient data is present in the manifest.

Deployer.register_strategy(contract_type, strategy)¶: If a contract_type requires linking, then you must register a valid strategy constructed with the Linker before you can deploy an instance of the contract_type.

Linker¶

If a contract factory requires linking, you must register a “strategy” for a particular contract factory with the deployer. It is up to you to design an appropriate strategy for a contract factory.

Two linker functions are made available:

deploy(contract_name, *args=None)¶: To deploy an instance of contract_name. If the contract constructor requires arguments, they must also be passed in.

link(contract_name, linked_type)¶: Links a contract_name to a linked_type. The linked_type must have already been deployed.

For example, the Escrow contract factory requires linking to an instance of the SafeSendLib before an Escrow contract instance can be deployed. This is how you would set up a strategy for Escrow

@pytest.fixture
def escrow_deployer(solc_deployer, w3, manifest_dir):
    escrow_manifest_path = manifest_dir / "escrow_manifest.json"
    return solc_deployer(escrow_manifest_path), w3


@pytest.fixture
def escrow_contract_instance(escrow_deployer):
    deployer, w3 = escrow_deployer
    escrow_strategy = linker(
        deploy("SafeSendLib"),
        link("Escrow", "SafeSendLib"),
        deploy("Escrow", w3.eth.accounts[0]),
    )
    deployer.register_strategy("Escrow", escrow_strategy)
    linked_escrow_package, _ = deployer.deploy("Escrow")
    return linked_escrow_package.deployments.get_deployment("Escrow")