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Getting started#

This guide explains how to run the first test in the Woke testing framework.


Before getting started, make sure to have the latest version of a development chain installed.

This is especially important in the case of Anvil, because it is under active development. To install the latest version of Anvil, run the following command:


Generating pytypes#

pytypes are Python-native equivalents of Solidity types. They are generated from a Solidity source code and are used in tests to interact with smart contracts.

The first step is to generate pytypes by running the following command:

woke init pytypes -w

Configuring compilation

Woke uses default configuration options that should work for most projects. However, in some cases, it may be necessary to configure the compilation process. For more information, see the Configuration page.

This command will create a pytypes directory in the current working directory. The -w flag tells Woke to watch for changes in the smart contracts and automatically regenerate the pytypes when a change is detected.

When a compilation error occurs, Woke generates pytypes for the contracts that were successfully compiled. pytypes for the contracts that failed to compile are not generated.

Writing the first test#


Solidity source code for all examples in this guide is available in the Woke repository.

To collect and execute tests, Woke uses the pytest framework under the hood. The test files should start with test_ or end with to be collected. It is possible to use all the features of the pytest framework like fixtures.

The recommended project structure is as follows:

├── contracts
│   └── Counter.sol
├── pytypes
└── tests

Connecting to a chain#

In single-chain tests, it is recommended to use the default_chain object that is automatically created by Woke. The connect decorator either launches a new development chain or connects to an existing one, if the second argument is specified. It is possible to connect using:

  • a HTTP connection (e.g. http://localhost:8545),
  • a WebSocket connection (e.g. ws://localhost:8545),
  • an IPC socket (e.g. /tmp/anvil.ipc).
from woke.testing import *

# launch a new development chain
# or connect to an existing chain
# @default_chain.connect("ws://localhost:8545")
def test_counter():

To run the test, execute the following command:

woke test tests/ -d

The -d flag tells Woke to attach the Python debugger on test failures.

Deploying a contract#

Every Solidity source file has its equivalent in the pytypes directory. These directories form a module hierarchy that is similar to the one in the contracts directory. The Counter contract from the previous example is available in the pytypes.contracts.Counter module.

Every contract has a deploy method that deploys the contract to the chain. The deploy method accepts the arguments that are required by the contract's constructor. Additionally, it accepts the following keyword arguments:

Argument Description
from_ Address, Account or a hex address string that will be used to deploy the contract (the transaction sender)
value amount of Wei to be sent to the contract
gas_limit maximum amount of gas that can be used in the transaction (max, auto or number)
return_tx True to return the full transaction object, False to return the return value (contract instance)
chain Chain to which the contract should be deployed

Sending transactions from any account

The from_ argument can be used to send transactions from any account (including contract) or address. However, this may come at a cost of decreased performance (see Performance considerations).

When sending transactions from an account with code (contract), the contract behaves as if it had no code during the execution of the transaction!

from woke.testing import *

from pytypes.contracts.Counter import Counter

def test_example():
    counter = Counter.deploy(from_=default_chain.accounts[0])

Interacting with a contract#

Woke testing framework distinguishes between two types of interactions with a contract:

  • calls - read-only requests that do not change the state of the blockchain,
  • transactions - requests that change the state of the blockchain.

By default, Woke uses calls to execute pure and view functions. It uses transactions to execute all other functions.

There are two more keyword arguments that the deploy method does not accept:

Argument Description
to Address, Account or a hex address string of the contract to which the request should be sent
request_type type of the request (call or tx)


The to argument can be used to override the address of the contract that is being called. This can be useful when a contract should be called through a proxy contract.

contract.initialize(owner, to=proxy)

If no from_ argument is specified:

  • default_chain.default_call_account is used to execute calls,
  • default_chain.default_tx_account is used to execute transactions.

default_call_account is initialized to the first account in the chain's account list. default_tx_account is left unset by default.

from woke.testing import *

from pytypes.contracts.Counter import Counter

def test_counter():
    default_chain.default_tx_account = default_chain.accounts[1]

    counter = Counter.deploy(from_=default_chain.accounts[0])
    assert counter.count() == 1

    # increment performed as a call does not change the state
    assert counter.count() == 1

    # setCount can only be called by the owner
    counter.setCount(10, from_=default_chain.accounts[0])
    assert counter.count() == 10

    # this will fail because the default account is not the owner
    with must_revert():
    assert counter.count() == 10