## Fuzz Tests Setup Now that we have written a lot of unit tests, we are going to write some fuzz tests. Let's create a new folder called `fuzz`. We will create a test file called `test_fuzz.py`. ```python from hypothesis.stateful import RuleBasedStateMachine, initialize, rule from script.deploy_dsc_engine import deploy_dsc_engine from moccasin.config import get_active_network from eth_constants import ZERO_ADDRESS from boa.util.abi import Address USERS_SIZE = 10 class StablecoinFuzzer(RuleBasedStateMachine): def __init__(self): super().__init__() self.dsc = deploy_dsc() self.dsc = deploy_dsc_engine(self.dsc) self.active_network = get_active_network() self.weth = self.active_network.manifest(named="weth") self.wbtc = self.active_network.manifest(named="wbtc") self.eth_usd = self.active_network.manifest(named="eth_usd_price_feed") self.btc_usd = self.active_network.manifest(named="btc_usd_price_feed") self.users = [Address("0x" + ZERO_ADDRESS.hex())] while Address("0x" + ZERO_ADDRESS.hex()) in self.users: self.users = [Address("0x" + ZERO_ADDRESS.hex()) for _ in range(USERS_SIZE)] stablecoin_fuzzer = StablecoinFuzzer.TestCase ``` We are going to import the `rule` from the `hypothesis.stateful` module. We will initialize our test suite here using the `initialize` function, and we need to import the `deploy_dsc_engine` from the `deploy_dsc_engine` module. We will set up all of our contracts. ```python from hypothesis.stateful import RuleBasedStateMachine, initialize, rule from script.deploy_dsc_engine import deploy_dsc_engine from moccasin.config import get_active_network from eth_constants import ZERO_ADDRESS from boa.util.abi import Address USERS_SIZE = 10 class StablecoinFuzzer(RuleBasedStateMachine): def __init__(self): super().__init__() self.dsc = deploy_dsc() self.dsc = deploy_dsc_engine(self.dsc) self.active_network = get_active_network() self.weth = self.active_network.manifest(named="weth") self.wbtc = self.active_network.manifest(named="wbtc") self.eth_usd = self.active_network.manifest(named="eth_usd_price_feed") self.btc_usd = self.active_network.manifest(named="btc_usd_price_feed") self.users = [Address("0x" + ZERO_ADDRESS.hex())] while Address("0x" + ZERO_ADDRESS.hex()) in self.users: self.users = [Address("0x" + ZERO_ADDRESS.hex()) for _ in range(USERS_SIZE)] stablecoin_fuzzer = StablecoinFuzzer.TestCase ``` We are going to create an array of users as well. We will create an array of ten different users, and we can even print the array. ```python from hypothesis.stateful import RuleBasedStateMachine, initialize, rule from script.deploy_dsc_engine import deploy_dsc_engine from moccasin.config import get_active_network from eth_constants import ZERO_ADDRESS from boa.util.abi import Address USERS_SIZE = 10 class StablecoinFuzzer(RuleBasedStateMachine): def __init__(self): super().__init__() self.dsc = deploy_dsc() self.dsc = deploy_dsc_engine(self.dsc) self.active_network = get_active_network() self.weth = self.active_network.manifest(named="weth") self.wbtc = self.active_network.manifest(named="wbtc") self.eth_usd = self.active_network.manifest(named="eth_usd_price_feed") self.btc_usd = self.active_network.manifest(named="btc_usd_price_feed") self.users = [Address("0x" + ZERO_ADDRESS.hex())] while Address("0x" + ZERO_ADDRESS.hex()) in self.users: self.users = [Address("0x" + ZERO_ADDRESS.hex()) for _ in range(USERS_SIZE)] stablecoin_fuzzer = StablecoinFuzzer.TestCase ``` We will import the Boa module and create a rule for our protocol. ```python from hypothesis.stateful import RuleBasedStateMachine, initialize, rule from script.deploy_dsc_engine import deploy_dsc_engine from moccasin.config import get_active_network from eth_constants import ZERO_ADDRESS from boa.util.abi import Address USERS_SIZE = 10 class StablecoinFuzzer(RuleBasedStateMachine): def __init__(self): super().__init__() self.dsc = deploy_dsc() self.dsc = deploy_dsc_engine(self.dsc) self.active_network = get_active_network() self.weth = self.active_network.manifest(named="weth") self.wbtc = self.active_network.manifest(named="wbtc") self.eth_usd = self.active_network.manifest(named="eth_usd_price_feed") self.btc_usd = self.active_network.manifest(named="btc_usd_price_feed") self.users = [Address("0x" + ZERO_ADDRESS.hex())] while Address("0x" + ZERO_ADDRESS.hex()) in self.users: self.users = [Address("0x" + ZERO_ADDRESS.hex()) for _ in range(USERS_SIZE)] stablecoin_fuzzer = StablecoinFuzzer.TestCase @rule def pass_me(): pass ``` Now, we can initialize our test suite and see it print out ten different addresses. ```bash mox test -s -k stablecoin_fuzzer ```