Merge pull request #260 from KPrasch/pyevm-dev

Custom private chain genesis parameters

.travis.yml

@@ -6,6 +6,10 @@ python:
 install:
 - pip install pipenv --upgrade
 - pipenv install --dev --three
+before_script:
+- VENV=$(pipenv --venv)
+- wget https://github.com/ethereum/solidity/releases/download/v0.4.23/solc-static-linux -O "${VENV}/bin/solc"
+- chmod +x "${VENV}/bin/solc"
 script:
 - pipenv run -- pytest --cov=nkms -v tests
 - codecov

tests/blockchain/eth/utilities.py

@@ -1,5 +1,9 @@
 from typing import List
 
+import pkg_resources
+from eth_tester import PyEVMBackend
+from eth_tester.backends import is_pyevm_available
+from eth_tester.backends.pyevm.main import get_default_genesis_params, get_default_account_keys, generate_genesis_state
 from web3 import Web3
 
 from nkms.blockchain.eth.agents import MinerAgent
@@ -39,3 +43,49 @@ def generate_accounts(w3: Web3, quantity: int) -> List[str]:
     assert accounts == 10, fail_message
 
     return addresses
+
+
+class TesterPyEVMBackend(PyEVMBackend):
+
+    def __init__(self, genesis_overrides=None):
+        """
+        Example overrides
+        ---------------------------------
+        coinbase: address_bytes
+        difficulty: int(default: 131072)
+        extra_data: bytes
+        gas_limit: int(default: 3141592)
+        gas_used: int(default: 0)
+        nonce: bytes
+        block_number: int
+        timestamp: int(epoch)
+        """
+
+        self.fork_config = {}
+
+        if not is_pyevm_available():
+            raise pkg_resources.DistributionNotFound(
+                "The `py-evm` package is not available.  The "
+                "`PyEVMBackend` requires py-evm to be installed and importable. "
+                "Please install the `py-evm` library."
+            )
+
+        self.reset_to_genesis(overrides=genesis_overrides)
+
+    def reset_to_genesis(self, overrides=None):
+        from evm.chains.tester import MainnetTesterChain
+        from evm.db import get_db_backend
+        from evm.db.chain import ChainDB
+
+        db = ChainDB(get_db_backend())
+        genesis_params = get_default_genesis_params()
+
+        # Genesis params overrides
+        if overrides is not None:
+            genesis_params.update(overrides)
+
+        account_keys = get_default_account_keys()
+        genesis_state = generate_genesis_state(account_keys)
+        chain = MainnetTesterChain.from_genesis(db, genesis_params, genesis_state)
+
+        self.account_keys, self.chain = account_keys, chain

tests/eth_fixtures.py

@@ -6,10 +6,9 @@ import tempfile
 import pytest
 import shutil
 import time
-from eth_tester import EthereumTester, PyEVMBackend
+from eth_tester import EthereumTester
 from geth import LoggingMixin, DevGethProcess
 from os.path import abspath, dirname
-from tests.blockchain.eth.utilities import MockMinerEscrowDeployer
 from web3 import EthereumTesterProvider, IPCProvider, Web3
 from web3.middleware import geth_poa_middleware
 
@@ -20,22 +19,13 @@ from nkms.blockchain.eth.deployers import PolicyManagerDeployer, NuCypherKMSToke
 from nkms.blockchain.eth.interfaces import Registrar, ContractProvider
 from nkms.blockchain.eth.sol.compile import SolidityCompiler
 from tests.blockchain.eth import contracts, utilities
+from tests.blockchain.eth.utilities import MockMinerEscrowDeployer, TesterPyEVMBackend
 
 
 #
 # Session fixtures
 #
 
-@pytest.fixture(scope='session')
-def solidity_compiler():
-    test_contracts_dir = os.path.join(dirname(abspath(contracts.__file__)), 'contracts')
-    compiler = SolidityCompiler(test_contract_dir=test_contracts_dir)
-    yield compiler
-
-#
-# Web3 provider backends
-#
-
 
 @pytest.fixture(scope='session')
 def manual_geth_ipc_provider():
@@ -113,31 +103,40 @@ def pyevm_provider():
     Provider backend
     https: // github.com / ethereum / eth - tester     # available-backends
     """
-    # TODO:     # eth_tester.backend.chain.header.gas_limit = 4626271
+    overrides = {'gas_limit': 4626271}
-    eth_tester = EthereumTester(backend=PyEVMBackend(),
+    pyevm_backend = TesterPyEVMBackend(genesis_overrides=overrides)
-                                auto_mine_transactions=True)
 
+    eth_tester = EthereumTester(backend=pyevm_backend, auto_mine_transactions=True)
     pyevm_provider = EthereumTesterProvider(ethereum_tester=eth_tester)
+
     yield pyevm_provider
 
 
 @pytest.fixture(scope='session')
-def web3(auto_geth_dev_ipc_provider):
+def solidity_compiler():
-
+    test_contracts_dir = os.path.join(dirname(abspath(contracts.__file__)), 'contracts')
-    w3 = Web3(providers=auto_geth_dev_ipc_provider)
+    compiler = SolidityCompiler(test_contract_dir=test_contracts_dir)
-    w3.middleware_stack.inject(geth_poa_middleware, layer=0)
+    yield compiler
-
-    assert len(w3.eth.accounts) == 1
-    utilities.generate_accounts(w3=w3, quantity=9)
-    assert len(w3.eth.accounts) == 10
-
-    yield w3
 
 
 #
 # Module Fixtures
 #
 
+
+@pytest.fixture(scope='session')
+def web3(pyevm_provider):
+
+    w3 = Web3(providers=pyevm_provider)
+    w3.middleware_stack.inject(geth_poa_middleware, layer=0)
+
+    if len(w3.eth.accounts) == 1:
+        utilities.generate_accounts(w3=w3, quantity=9)
+    assert len(w3.eth.accounts) == 10
+
+    yield w3
+
+
 @pytest.fixture(scope='module')
 def contract_provider(web3, registrar, solidity_compiler):
     tester_provider = ContractProvider(provider_backend=web3, registrar=registrar, sol_compiler=solidity_compiler)
@@ -153,9 +152,10 @@ def registrar():
 
 
 @pytest.fixture(scope='module')
-def chain(contract_provider):
+def chain(contract_provider, airdrop=False):
     chain = TesterBlockchain(contract_provider=contract_provider)
 
+    if airdrop:
         one_million_ether = 10 ** 6 * 10 ** 18  # wei -> ether
         chain._global_airdrop(amount=one_million_ether)
 
@@ -166,11 +166,11 @@ def chain(contract_provider):
 
 
 # 
-# API #
+# Deployers #
 # 
 
 
-@pytest.fixture()
+@pytest.fixture(scope='module')
 def mock_token_deployer(chain):
     token_deployer = NuCypherKMSTokenDeployer(blockchain=chain)
     token_deployer.arm()
@@ -178,7 +178,7 @@ def mock_token_deployer(chain):
     yield token_deployer
 
 
-@pytest.fixture()
+@pytest.fixture(scope='module')
 def mock_miner_escrow_deployer(token_agent):
     escrow = MockMinerEscrowDeployer(token_agent=token_agent)
     escrow.arm()
@@ -186,7 +186,7 @@ def mock_miner_escrow_deployer(token_agent):
     yield escrow
 
 
-@pytest.fixture()
+@pytest.fixture(scope='module')
 def mock_policy_manager_deployer(mock_miner_escrow_deployer):
     policy_manager_deployer = PolicyManagerDeployer(miner_agent=mock_token_deployer)
     policy_manager_deployer.arm()
@@ -195,22 +195,23 @@ def mock_policy_manager_deployer(mock_miner_escrow_deployer):
 
 
 #
+# Agents #
 # Unused args preserve fixture dependency order #
 #
 
-@pytest.fixture()
+@pytest.fixture(scope='module')
 def token_agent(chain, mock_token_deployer):
     token = NuCypherKMSTokenAgent(blockchain=chain)
     yield token
 
 
-@pytest.fixture()
+@pytest.fixture(scope='module')
 def mock_miner_agent(token_agent, mock_token_deployer, mock_miner_escrow_deployer):
     miner_agent = MinerAgent(token_agent=token_agent)
     yield miner_agent
 
 
-@pytest.fixture()
+@pytest.fixture(scope='module')
 def mock_policy_agent(mock_miner_agent, token_agent, mock_token_deployer, mock_miner_escrow_deployer):
     policy_agent = PolicyAgent(miner_agent=mock_miner_agent)
     yield policy_agent